ERCBH2S A Model for Calculating Emergency Response and

ERCBH2S A Model for Calculating Emergency Response and
ERCBH2S
A Model for Calculating Emergency
Response and Planning Zones
for Sour Gas Wells, Pipelines, and
Production Facilities
Volume 3: User Guide, Version 1.20
ERCBH2S was developed for the Energy Resources Conservation Board (ERCB) by:
Michael J. Zelensky, M.Sc., P.Eng.
Public Safety and Air Quality Management (PSAQM Inc.)
Brian W. Zelt, Ph.D., P.Eng.
Zelt Professional Services Inc.
The project was managed by Gary Neilson, B.Sc. (Hons), P.Phys. of the ERCB’s Field
Surveillance and Operations Branch. The Emergency Management Group’s patience and creative
suggestions are gratefully acknowledged.
The models and reports were prepared for the ERCB Field Surveillance and Operations Branch.
The Emergency Management Group’s support, patience and creative suggestions are gratefully
acknowledged.
Clearstone Engineering Ltd. provided the real fluids thermodynamic program ERCBFLASH.
Special thanks go to Dr. David J. Wilson, P.Eng. of the University of Alberta, who provided expert
technical guidance and several new solutions for hazard analysis implemented in the models.
This project has benefited from a review by stakeholders. The Canadian Association of Petroleum
Producers also sponsored a peer-review of the science, provided funding for the batch input
function and participated in a Pilot Project to test the model. Thank-you for your comments and
support.
The December 2006 draft was prepared by Brian Zelt. The January 2008 draft was revised by
Michael Zelensky. The April 2008 release was revised by Kathy Hubbard of the ERCB with
assistance from Brian and Michael. The July 2008 release was revised by Kathy Hubbard with
final editing by Michael J. Zelensky. The December 2010 release was revised by Hua Deng with
final editing by Michael J. Zelensky.
ENERGY RESOURCES CONSERVATION BOARD
ERCBH2S: A Dispersion Model for Calculating Emergency Response and Planning Zones for Sour
Wells, Sour Pipelines, and Sour Production Facilities, Volume 3: User Guide, Version 1.20
December 2010
Published by
Energy Resources Conservation Board
Centennial Place
Suite 1000, 250 – 5 Street SW
Calgary, Alberta T2P 0R4
Telephone: 403-297-2625
Fax: 403-297-3520
Web site: www.ercb.ca
Liability Disclaimer
These models, software and documentation were prepared by the ERCB (Energy Resources
Conservation Board) and/or Clearstone Engineering Ltd., to the specifications set by ERCB.
ERCB warrants that the SOFTWARE will perform substantially in accordance with the provided
documentation. Neither ERCB and/or Clearstone Engineering Ltd., nor any person acting on their
behalf, makes any warranty, guarantee, or representation, expressed or implied, that the software
and related materials, without limitation, are free of errors, are consistent with any standard of
merchantability or will meet user's requirements for a particular application, that any calculations
performed by the software are correct or accurate, that the software is compatible with particular
computer systems, computer peripherals and other software packages, or that the software will run
uninterrupted.
EXCEPT AS PROVIDED ABOVE, THIS DOCUMENTATION AND SOFTWARE IS LICENSED "AS IS"
WITHOUT WARRANTY AS TO ITS PERFORMANCE. NO OTHER WARRANTIES APPLY. ERCB AND/OR
CLEARSTONE ENGINEERING LTD., DISCLAIM ALL OTHER WARRANTIES, EITHER EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THIS LIMITED WARRANTY GIVES YOU SPECIFIC LEGAL
RIGHTS. YOU MAY HAVE OTHERS, WHICH VARY FROM PROVINCE TO PROVINCE.
IN NO EVENT SHALL ERCB AND/OR CLEARSTONE ENGINEERING LTD., OR THEIR SUPPLIERS BE
LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING, WITHOUT LIMITATION, DAMAGES FOR
LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION,
CONSEQUENTIAL DAMAGES, OR OTHER PECUNIARY LOSS, HOWSOEVER ARISING OUT OF THE USE,
ATTEMPTED USE OF OR INABILITY TO USE THIS PRODUCT, EVEN IF ERCB AND/OR CLEARSTONE
ENGINEERING LTD. HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
TABLE OF CONTENTS
1.
Introduction...................................................... 1
Emergency Response and Planning Zone Requirements........................................ 1
Where to begin?............................................................................................................ 2
ERCBH2S Components................................................................................................ 3
User Qualifications ....................................................................................................... 3
Suitable Technical Background
4
ERCBH2S Users
5
Further Information ...................................................................................................... 6
How this Document is Organized ............................................................................... 6
2.
Installation ....................................................... 7
Minimum System Requirements ................................................................................. 8
About this Guide........................................................................................................... 8
Where to Go for Help.................................................................................................... 9
ERCB Support
9
Overview of the Installation Process.......................................................................... 9
STEP 1: Installing setup.exe: Complete Program Installation .............................. 10
STEP 2: Activating the ERCBH2S Add-In................................................................. 12
Add-In Manager Activation (Recommended)
12
Single Session Activation
14
3.
Quick-Start ..................................................... 16
4.
Program Operation ......................................... 27
Introduction ................................................................................................................. 27
User-Interface.............................................................................................................. 28
Overview – The ERCBH2S Template file in Excel
28
The ERCBH2S Excel Pages
29
Typical or Technical View? Hidden Technical Pages
32
Excel Functionality
33
ERCBH2S Excel Menus
33
Technical Submenu
Batch Submenu
Setup Submenu
34
35
37
ERCBH2S Excel Button-Bar
38
Saving Scenarios as Excel Files
40
Importing and Exporting ERCBH2S BATCH Page
40
ERCBH2S Excel Print Settings
43
ERCBH2S Excel Pages – RED FLAG WARNINGS
43
The ERCBH2S Calculation Process.......................................................................... 43
Run ERCBSLAB
43
Gas Well Calculation Process
46
Liquid Pipeline and Liquid Well Calculation Process
48
Gas Pipeline Calculation Process
48
ESD Closure
Ae/Ap Ratio Search
Calculate EPZ
5.
49
50
51
INPUTS Page .................................................. 53
Entering Data .............................................................................................................. 54
Erasing the Inputs Page............................................................................................. 55
TABLE OF CONTENTS
i
Red Flags and other Warnings.................................................................................. 55
Red Flag Warnings
55
Missing Entry
Out of Bounds Entry
Recalculation Required
56
56
56
Orange Warnings
57
Orange Resets
58
Green Notifications
59
Administrative ............................................................................................................. 59
ERCBH2S Page Labels
63
Sour Operation Type
63
Analysis Type
65
SOURCE MITIGATION - General
Licensee/Applicant Responsibility
66
66
Gas Pipeline ................................................................................................................ 67
Gas Pipeline Group- Source Mitigation Sub-section
71
When to Change the Default Settings
Gas Pipeline Group - Orange Resets
72
74
Gas Well....................................................................................................................... 75
Gas Well - Source Mitigation Sub-section
77
When to Change the Default Settings
Gas Well Group - Orange Resets
78
79
Liquid Pipeline or Liquid Well ................................................................................... 79
Liquid Pipeline and Liquid Well Group - Source Mitigation Sub-section
86
When to Change the Default Settings
Liquid Pipeline or Liquid Well Group - Orange Resets
87
88
Sour Gas Composition............................................................................................... 89
Advanced User Selected Case .................................................................................. 90
6.
Calculation Pages .......................................... 92
Common Pages........................................................................................................... 92
CONSTANTS
92
ERCB Default Inputs
Physical Constants
92
95
SHARED
96
ERCBFLASH
96
ERCBFLASH OUTPUT
96
ERCBSLAB
96
ERCBSLAB OUTPUT
96
TOX OUTPUT
97
MAX OUTPUT
97
METMATRIX
97
HAZARD DISTANCES
98
Gas Pipeline Pages..................................................................................................... 99
SOUR GAS PIPELINE
99
ESD CLOSURE
100
AeAp ITERATION
100
Gas Well Page ...........................................................................................................100
SOUR GAS WELL
100
Liquid Pipeline/Well Page ........................................................................................101
SOUR LIQUID
101
7.
Output Pages................................................ 102
ERP SUMMARY.........................................................................................................102
Erasing Calculation Results
105
HAZARDS ..................................................................................................................106
User Selected Case
106
Maximum of Screening Hazard Cases
108
TABLE OF CONTENTS
ii
GRAPH-MET ..............................................................................................................109
GRAPH-ERCBSLAB (x) ............................................................................................112
GRAPH-TRANSIENT(x).............................................................................................113
GRAPH-STEADY(x)...................................................................................................115
8.
Batch Page ................................................... 117
Introduction ...............................................................................................................117
Working with the BATCH Page – Summary Overview ..........................................118
Data Entry
118
Calculating Emergency Response and Planning Zones
118
Batch Page / Inputs Page Relationship ..................................................................119
General
119
Input Data Connection Between the Pages
119
Calculation Results (Outputs) Data Connection Between the Pages
120
From INPUTS to BATCH
From BATCH to INPUTS
120
121
Entering Data to the Batch Page .............................................................................122
Copying, Deleting, and Editing Rows of Data on the BATCH Page
123
Deleting Rows of Data
124
Checking for Red Flag and Other Warnings
125
Batch Control Group ................................................................................................126
Run or Not Run
126
Print/Save
126
Batch Operations......................................................................................................127
Check for Scenario Duplicates
127
Batch Run ERCBSLAB
128
Batch Calculate EPZ
128
Batch Output Group .................................................................................................129
Errors
129
Output Data Fields
130
Saving a Batch Page as an Excel File ....................................................................130
Creating a Batch Export File for ERCB Submission.............................................131
Batch Page Tutorial ..................................................................................................132
9.
Pipeline Gathering Systems......................... 133
Overview ....................................................................................................................133
Equivalent Segment Length (between ESDs)
134
Equivalent Cumulative Pipeline Volume (between ESDs)
135
Gathering System Analysis .....................................................................................136
NODE
PIPELINE SEGMENT
Example Illustration 1 (Single Segment)
Illustration 1 - Summary Discussion
Example Illustration 2 (Connecting Segments)
Illustration 2 – Summary Discussion
Conclusion
136
137
137
138
138
140
140
Gas Gathering System Analysis – Tutorial ............................................................141
Introduction
141
NODE LABEL
NODE NUMBER
NODE POSITION
PIPELINE SEGMENT LABEL (SCENARIO NAME)
141
141
143
143
Tutorial
143
Tutorial Variation 1 – Complex Node Location
148
Tutorial Variation 2 – Other Licensee Tie-in
150
Formulae for Pipeline Networks..............................................................................153
10. EXAMPLE 1: Gas Pipeline ........................... 154
TABLE OF CONTENTS
iii
Tutorial.......................................................................................................................154
Step-By-Step Procedure
Variation 1: Segment Length
157
164
11. EXAMPLE 2: Gas Well.................................. 168
Tutorial.......................................................................................................................168
Step-By-Step Procedure
Variation 1: Sour Gas Well – Change Time to Ignition
169
177
12. Troubleshooting and FAQs........................... 183
Non-reportable Error Messages..............................................................................183
Reportable Error Messages .....................................................................................183
ERROR #9
ERROR #1004
ERROR #9005
Version Issue
184
184
184
185
Installation Troubleshooting ...................................................................................186
Program Troubleshooting........................................................................................186
Not an ERCBH2S Spreadsheet
186
General Troubleshooting .........................................................................................186
Excel Security Levels and Running the ERCBSLAB Application
Interfacing with other User Spreadsheets
186
187
ERCBFLASH ERRORS .............................................................................................188
ERCBSLAB ERRORS ...............................................................................................189
13. References ................................................... 197
TABLE OF CONTENTS
iv
1. Introduction
ERCBH2S, a Model for Calculating
Emergency Response and Planning Zones
for Sour Gas Facilities
Emergency Response and Planning Zone
Requirements
The Energy Resources Conservation Board (ERCB) has developed ERCBH2S for
Calculating Emergency Response and Planning Zones for Sour Gas Facilities
which are compliant with the requirements of Directive 071 – Emergency
Preparedness and Response Requirements for the Petroleum Industry.
This User Guide is for the ERCBH2S Emergency Response and Planning (ERP)
zones dispersion modelling spreadsheet.
The User Guide outlines how to calculate ERP zones using the model and
provides much of the information about the User inputs required for the
calculations. For a submission to the ERCB, complete requirements are provided
in Directive 071.
1 Introduction
1
Where to begin?
Several chapters in this manual take the user step-by-step through various
applications of the ERCBH2S model, while others are designed for user reference.
To use ERCBH2S it is not necessary to read the entire User Guide. A suggested
format (in order) for a first time user is:
1.
User Qualifications in Chapter 1 (this chapter)
2.
Program Installation – Chapter 2
3.
Quick-Start – Chapter 3
4.
Inputs Page – Chapter 5. This chapter describes the ERCBH2S
INPUTS page in detail, cell by cell. No user should be entering
data to ERCBH2S without referencing this chapter.
5.
*Gas Well Example Tutorial – Chapter 11
6.
Batch Page – Chapter 8
If modelling pipelines, then continue through:
7.
Gas Pipeline Example Tutorial – Chapter 10
8.
Pipeline Gathering Systems – Chapter 9
*Even if a user is not modelling wells, the Gas Well Example Tutorial is
recommended because it requires fewer inputs than pipeline modelling, and it
acquaints the user with the ERCBH2S BATCH page.
1 Introduction
2
ERCBH2S Components
The ERCBH2S model documentation is comprised of several components that are
described in the following table.
Volume
Description
Directive 071: Emergency
Preparedness and Response
Requirements for the Petroleum
Industry
This directive provides the requirements for the
industrial operator. It covers not only sour operations
but any activity where a hazard exists with the potential
to cause a risk to the public.
Overview
Written for industrial operators and public with a
particular interest in ERCBH2S. It provides an overview
of the ERCB hazard management process and presents
a higher level summary of the key components of the
ERCBH2S software.
Written for the technical specialist and to document the
complex science within ERCBH2S. It provides the
science required to calculate the hazard zone and the
basis for selecting the components used to make the
calculations within ERCBH2S.
Volume 1:
Technical Reference Document
Version 1.20
Volume 2:
Emergency Response Planning
Endpoints
Written for the technical specialist with a particular
interest in toxicology. It presents the data available to
choose an EPZ endpoint, toxicological calculations and
the EPZ endpoint values for H2S.
Volume 3:
User Guide
Version 1.20
Written for the ERCBH2S user, it provides a description
of the spreadsheet program usage, including installation
instructions, descriptions of input and output from the
program. Step-by-step tutorials to help familiarize the
user with the program interface and interpret results are
included.
ERCBH2S
Spreadsheet based program used to calculate planning
zones. Includes ERCBSLAB and ERCBFLASH
programs.
All of these documents are available on the ERCB website.
User Qualifications
ERCBH2S is freely distributed to update emergency response planning within
Alberta. ERCBH2S is a complex tool that calculates site-specific ERP zones
1 Introduction
3
using thermodynamics, fluid dynamics, atmospheric dispersion modelling, and
toxicology. Hazard assessment is a multidisciplinary and iterative task with many
assumptions and judgments. The approach, default ERCB inputs and constants
have been carefully selected in order to balance hazard and safety to ensure that
the ERP zones are representative yet err on the side of public safety.
ERCBH2S models were created so that a minimal amount of technical
background is required to run the models. However, there remains some technical
knowledge required to supply suitable inputs and the ability to understand
whether the output is appropriate for the inputs and meets the needs of
stakeholders. The user must recognise that the models are technical in nature and
the correct interpretation of the result may require technical expertise that
proceeds from consequences of the inputs. That is, garbage-in equates to
garbage-out.
The models have been created with a professional commitment to environmental
protection and safeguarding the well-being of the public. It is the responsibility of
the software user to accept and continue this commitment in their application of
the software. The software is supplied as a tool to assist the user to comply with
applicable statutes, regulations and bylaws. Neither the software nor application
of the software is intended to replace statutes, regulations or bylaws.
Suitable Technical Background
Environmental issues are interdisciplinary in nature. The practice of
environmental science requires the integration of diverse disciplines and
philosophies; many projects will require a team of appropriate specialists to
address complex environmental issues. Persons doing the assessment should
undertake only that aspect of environmental work that they are competent to
perform by virtue of training and experience. Thus they should seek out and use
appropriate Environmental Specialists to provide expert advice on certain
environmental issues.
The basis of the models is technical with expertise required in chemistry,
thermodynamics, atmospheric physics, meteorological processes, industrial
processes and regulatory affairs. While the full technical background is not a
requirement to execute the models, the user of the software is required to have a
general engineering and environmental science background; a general knowledge
of the emission sources: wells, pipelines, and pipeline networks; and a working
knowledge of the most current version of:
•
•
•
•
ERCB Directive 071 – Emergency Preparedness and Response
Requirements for the Petroleum Industry
ERCB Directive 056 – Energy Development Applications and Schedules
ERCB Directive 026 – Setback Requirements for Oil Effluent Pipelines
Alberta Environment Air Quality Modelling Guideline.
1 Introduction
4
ERCBH2S Users
1. should develop and maintain a reasonable level of understanding, awareness
and monitoring system (check that outputs are appropriate for model inputs) of
the software, its inputs and its outputs;
2. shall use appropriate expertise of specialists in areas where the user’s
knowledge alone is not adequate to address the input or interpret the output;
3. shall apply professional and responsible judgment in their considerations of the
model inputs and outputs;
4. shall comply with regulatory requirements and endeavour to exceed or better
them;
5. shall disclose information necessary to protect public safety to appropriate
authorities; and,
6. should actively work with others improve their understanding and practices.
There are many technical inputs required by ERCBH2S
to perform the ERP zone calculations. Some have been
prescribed by ERCB mandatory default entries. Others
are input by the User for the specific sour gas facility.
Source Mitigation entries must be based on actual
capabilities.
Use of ERCBH2S and understanding whether the
predictions are appropriate for the user inputs still,
however, requires some specific technical
understanding. If terminology such as “hazards,
endpoints, fluctuations, choked flow, or stability class” is
unfamiliar, you may require further expertise to operate
the model and describe the results.
1 Introduction
5
Further Information
For all of the information related to ERCBH2S and latest updates visit the ERCB
website:
http://www.ercb.ca/portal/server.pt/gateway/PTARGS_0_0_303_263_0_43/http%
3B/ercbContent/publishedcontent/publish/ercb_home/industry_zone/rules__regul
ations__requirements/directives/directive071_model.aspx
How this Document is Organized
This User Guide is organized as both an instructional guide and a tutorial. This
guide does not describe the technical basis (see the companion document
“Volume 1: Technical Reference Document” for a technical description
of the equations and formulations), but describes the installation and use of the
ERCBH2S program. This guide is divided into the following chapters:
Installation
How to install the ERCBH2S program
Quick-Start
A tutorial to familiarize the user with basic functions
to navigate the program
Operation
INPUTS page
Calculation Pages
Output Pages
Batch Processing
Pipeline Gathering Systems
Example 1: Gas Pipeline
Example 2: Gas Well
1 Introduction
How the ERCBH2S program works
A description of the user inputs
A description of the calculation pages
A description of the output pages
A description of how to set up the ERCBH2S
program in batch mode processing
A description of how to set up the ERCBH2S
program for assessment of gas and liquid pipeline
gathering system networks, including a tutorial
example
A tutorial for a gas pipeline segment release
A tutorial for a gas well release
6
2.
Installation
This chapter describes how to install the ERCBH2S software. The install package
includes the following modules:
•
ERCBH2S.xla - a Microsoft®-Excel application software for
Windows® containing macros and detailed calculations to
determine emergency response and planning Zones for gas wells,
gas pipelines and liquid pipelines.
•
ERCBH2S-Inputs(V120).xls- a template spreadsheet that is the
user-interface with intermediate calculations for sour gas
emergency response planning for gas well, gas pipelines, and
liquid pipelines/wells.
•
Example files - spreadsheets using the ERCBH2S-Inputs(V120).xls
with example values already filled in.
•
ERCBSLAB.dll – a stand-alone program based upon the USEPASLAB heavier than air, air quality model. ERCBSLAB includes
calculations for gas well blowouts, gas pipeline blowdowns, liquid
pipeline vapours, indoor exposures and toxic load for sour gas
releases containing hydrogen sulphide (H2S) releases.
•
ERCBFLASH.dll – a stand-alone program to calculate real gas
properties of hydrocarbons required for the characterization of the
releases.
The program extension .dll stands for dynamic link library. Programs are
converted into dlls to allow accessible functionality with Microsoft Excel. The
ERCBH2S installation contains all of the ERCBH2S programs, application and the
template spreadsheets.
2 Installation
7
Minimum System Requirements
ERCBH2S is a Windows® based software
application requiring Microsoft® Excel. The
minimum system requirements* are:
•
•
•
•
•
•
•
•
Windows® 7, Vista, XP, 2000, NT 4.0(SP3 or
greater)
Microsoft® Excel. (Program testing completed on
Office 2000, Office 2002,Office 2003, Office 2007
and Office 2010. The program only runs on 32bit
Office.)
16 MB free hard disk space
800x600 resolution
300 MHz processor
256 MB RAM
Windows® - compatible mouse
Optional: colour or b/w printer (300 dpi or better
recommended)
* The installation of the software requires
Administration level security privileges on the
computer. If you do not have these privileges
About this Guide
The following symbols and conventions are used in this guide
Bold
Used for menu, command, and keyboard selections you
make and screens you will see.
Italics
Used for emphasis and to identify new terms
text
User typed responses or entries
Helpful information about a particular topic.
Important information to prevent problems and ensure that
you are successful in using the software.
link
2 Installation
A hyperlink to a section within the User Guide, an internet
web site or email address
8
Where to Go for Help
For additional help with the ERCBH2S program, its installation and use, contact
the following:
ERCB Support
Check the site below for detailed support for ERCBH2S including the latest
revisions of the model, technical reference document, user guide and for
important user messages:
http://www.ercb.ca/portal/server.pt/gateway/PTARGS_0_0_303_263_0_43/http%
3B/ercbContent/publishedcontent/publish/ercb_home/industry_zone/rules__regul
ations__requirements/directives/directive071_model.aspx
Please send comments, program operation problems and problem spreadsheets to:
[email protected]
Overview of the Installation Process
If you have not already done so, download the installation software from the
ERCB website (see above).
The single install program setup.exe file contains all of the software required for
the ERCBH2S program (including ERCBSLAB, ERCBFLASH and template
spreadsheet) to run within the users existing Microsoft Office (including Excel)
environment.
STEP 1: The install program (provided in the software download) installs the
ERCBH2S as a program in the system registry.
The installation software allows two options for the software installation:
•
Full Installation (Recommended)
Installs ERCBH2S, ERCBSLAB, ERCBFLASH and template
spreadsheet. Creates a subdirectory for the spreadsheet template
files.
•
Custom Installation
Installs only selected components.
2 Installation
9
STEP 2: After you have run the install software, you must complete the
installation using either of two options:
•
You may activate the ERCBH2S Excel add-in so that ERCBH2S is loaded
every time you open Excel, or
•
You can launch the ERCBH2S program for a single Excel session.
The install program will create folders and copy the following files to the folders,
or you may select the destination:
File
Default folder
ERCBH2S.xla
ERCBH2S-inputs(V120).xls
Uninstall ERCBH2S
C:\program files\ERCBModels\ERCBH2S
ERCBSLAB.for
MODULES.for
C:\program files\ERCBModels\ERCBH2S\SOURCE
ERCB_SLAB.dll
ERCB_FLASH.dll
ERCB_THERMOU.dll
C:\windows\system32
The dynamic link library (*.dll) files may be installed
to alternate folder locations during the installation.
STEP 1:
Installing setup.exe:
Complete Program Installation
If you get an error message regarding Administrator
privileges refer to the “Administration Privilege for
Windows” in the “Troubleshooting and FAQs” section,
later in this guide.
To ensure a successful installation, follow the steps outlined below.
2 Installation
10
1.
Using Windows Explorer or the My Computer icon on your computer
desktop, locate the installation file you downloaded from the ERCB
website.
Double click the installation file to open and run the install sequence.
The InstallShield Preparing to Install window will be briefly displayed.
The Welcome to the InstallShield Wizard for ERCBH2S welcome
and loading screen will appear.
Answer Next to continue installing the ERCBH2S software, or Cancel
to end the installation.
2.
The ERCBH2S License Agreement screen will appear.
The License Agreement covers both the ERCBSLAB and ERCBFLASH
programs.
3.
After reading the License Agreement, select I accept the terms of the
license agreement.
Click Next to continue
4.
The Customer Information screen will appear.
5.
Enter you User Name and Company Name.
If there are separate users that log in to use your computer, you can choose
whether you would like all users to be able to use the software or just you.
The All Users option is recommended.
Make your choice and click Next.
The Destination Folder screen will appear.
6.
In the Destination Folder section of the screen, you can see the default
location where the software will be installed. If you wish to change this,
click Browse and choose a new location.
When you are ready, click Next.
The InstallShield Ready to Install the Program window should
appear.
2 Installation
11
7.
Click Install.
The InstallShield Installing… window will briefly appear and display the
status of the installation of the program modules being installed.
The InstallShield Wizard Complete window will appear.
8.
Click Finish to end the wizard InstallShield and complete the installation
of the ERCBH2S program.
STEP 2:
Activating the ERCBH2S Add-In
In STEP 1, the software required for the ERCBSLAB and ERCBFLASH
programs is installed. STEP 2 - Activating the ERCBH2S ADD-In, the
ERCBH2S.xla is configured to run within Microsoft Excel. There are two options
for this configuration:
1. Configure Excel so that ERCBH2S.xla application is loaded every time
Excel is opened. (Recommended)
The advantage with this configuration is that a template file
(ERCBH2S-inputs(V120).xls or example files) can be opened and the
ERCBH2S calculations can be performed without requiring the user to
additionally load the ERCBH2S.xla application program.
2. Run the ERCBH2S.xla program for a single session of calculations.
The advantage with this configuration is that users using Excel
frequently for other than ERCBH2S calculations are not loading the
ERCBH2S.xla application and unnecessarily occupying computer
resources.
The user can change the configuration between the two
options at a later date, by de-activating the ERCBH2S Addin within Excel and using the alternative configuration.
Add-In Manager Activation
(Recommended)
The Excel Add-in Manager is used to activate Excel Add-in applications. Note
that by activating the add-in in this way, it will always be available in the menu
bar when you start Excel (unless you turn it off manually). In this case, you do
not need to change Excel’s security setting.
2 Installation
12
By activating the ERCBH2S.xla Add-in using the Excel Addin Manager, the ERCBH2S application will always be
available in the menu bar when you start Excel (until such
time as you turn it off, also using Excel Add-in Manager).
The ERCBH2S application menu bar is displayed but is
active only with ERCBH2S template files (e.g., ERCBinputs(V120).xls or renamed copies).
Follow these steps to activate the add-in.
1.
Open Microsoft Excel
ERCBH2S is designed to be compatible with Microsoft Excel from Office®
2000 or higher version.
2.
On the main menu bar, click on Tools
Select Add-Ins… from the list of operations.
If “Add-Ins…” is not displayed on the menu, select “»” to display the full
list of menu options. Alternatively, right-click in the tool-bar area, select
Options and un-check the “Menus show recently used commands first”
3.
The Add-Ins manager window will appear
A list of Excel add-ins that are currently registered with the Add-In Manager
are displayed. Several may appear activated, by displaying a check mark
next to the title of the add-in.
Click Browse… to locate the ERCBH2S.xla add-in.
4.
The Browse window will be displayed.
5.
Locate the ERCBSLAB.xla add-in by navigating to the installation folder
you selected during STEP 1 - Software Installation. If you installed to the
default directory, the path is:
C:\Program Files\ERCBMODELS\ERCBH2S
6.
Click on the ERCBH2S.xla file.
A version number may be displayed after the “ERCBH2S” to identify the
program version number.
2 Installation
13
7.
Click OK.
The ERCBH2S add-in will be displayed in the add-in Manager, as shown
below. If the ERCBH2S add-in is not ‘checked’, then click using the
mouse in the box beside “ERCBH2S”, to display a check-mark.
8.
Click OK to complete the process.
ERCBH2S will now be displayed in the main menu bar.
The ERCBH2S button bar will appear when an
ERCBH2S template spreadsheet is opened
9.
Skip the “Single Session Activation” and follow the instructions in the
“Quick-Start” section
Single Session Activation
To launch the ERCBH2S.xla add-in for a single session, follow these steps:
10. Click on the Start menu button on your computer desktop.
Select Programs
2 Installation
14
Select ERCBMODELS
Select ERCBH2S
Select Launch ERCBH2S.xla
11. The Microsoft Excel application window will open.
ERCBH2S will now be displayed in the main menu bar.
The ERCBH2S button bar will appear when an ERCBH2S
template spreadsheet is opened
To change the security setting in Excel, go to the Tools menu then select
Macro and then Security. In the Security window, you can change the
setting to Medium, which will allow you to run the macro.
When Excel is closed the ERCBH2S application will close
also. If Excel is restarted, the ERCBH2S application will not
be opened unless you repeat the procedure described in
this section.
12. Continue to follow the instructions in the “Quick-Start” section.
2 Installation
15
3.
Quick-Start
Now that you have installed the software you will run a Quick-Start tutorial to
become familiar with ERCBH2S and how to calculate Emergency Response and
Planning (ERP) zones. Complete the following steps:
If you have pre-set the install option for ERCBH2S.xla (STEP 2:
Activating the ERCBH2S Add-In on page 12) go directly to step 2 in
this Quick-Start tutorial. Otherwise, begin at step 1.
1.
Click on the Start menu button on your computer desktop.
Select Programs
Select ERCBModels
Select ERCBH2S
Select Launch ERCBH2S.xla
(The ERCBH2S menu in Excel is now launched)
Choose ‘Enable Macros’
2.
Click on the Start menu button on your computer desktop.
Re-select Programs
Re-select ERCBModels
Select ERCBH2S-Inputs(V120).xls
(An ERCBH2S example file in Microsoft Excel is now launched)
3 Quick-Start
16
3.
The example files already contain in the row 11-13 in the BATCH page. It
opens on the ABOUT page, which provides a summary of the Introduction
section of the User Guide and brief Instructions. Notice the Legend and
colour scheme used for cells and sheet tabs. (Some earlier versions of
Excel do not display the page/sheet tabs in colour.)
4.
Are the ERCBH2S menu and menu-bar displayed and activated (non-grey)?
If so, continue to the next step. If not, then ERCBH2S.xla was NOT
launched, and you need to return to step 1 in this Quick-Start tutorial.
5.
Select the INPUTS page.
Scroll up and down. The INPUTS page for example files are already
completed, allowing the user to view example entries.
Because this INPUTS page was created for a tutorial, each of the three
‘details’ sections (Gas Pipeline, Gas Well and Liquid Pipeline/Well) have
been completed with sample user entries. Normally a user completes only
one of the three the details sections – the one related to the sour operation
type being modelled.
Input fields are shown with white background, input prompts and
comments in green, and default or calculation (protected) fields in grey.
All user entries are in column C.
3 Quick-Start
17
6.
The first section of the INPUTS page, titled ADMINISTRATIVE, is
always available for user inputs (column C).
7.
Delete the user entry for ‘BA CODE’ in row 4.
Notice the red flag warning at the top of the page.
The red flag indicates 1 missing entry for the ERCB Submission and the
Required for ERCB submission
warning appears in column E.
Now delete the user entry for Surface Elevation in row 21.
Notice that the red flag remains but the message inside it has changed.
Also, there is now a warning in column E for row 21
Required for calculation
.
This warning appears for missing user inputs that are required for the
ERCBH2S calculations to proceed. Either select the ‘Undo’ button twice (to
replace the last two deleted entries) or replace the “A” entry in row 4 and the
“1000” entry in row 21. The red flag disappears along with the orange
warnings in column E.
For the remainder of this tutorial, you can ignore any red flags that appear
at the top and bottom of the page.
8.
Below ADMINISTRATIVE are three sections titled – GAS PIPELINE,
GAS WELL, and LIQUID PIPELINE OR LIQUID WELL.
3 Quick-Start
18
Access to each of these three sections is controlled by the user selection in
SOUR OPERATIONS TYPE (located within ADMINISTRATIVE).
9.
Locate SOUR OPERATIONS TYPE within the ADMINISTRATIVE
section.
The type of sour gas or sour liquid operation selected determines which part
of the INPUTS page is ‘active’.
Toggle between the eleven sour operations types and observe how the
SELECTED INPUTS FLAVOUR: GAS PIPELINE, GAS WELL and
LIQUID PIPELINE/WELL display changes on the rest of the INPUTS
page. Depending on the user selection, one of the sour operations sections is
available for user input (non-grey) and the other two are greyed-out.
Remember; for this tutorial you can ignore red flags that appear at the top
and bottom of the page. Some selections will generate a red flag.
Also notice that, depending on the selection made, there are some rows
within the ‘Gas Pipeline’ and ‘Liquid Well or Liquid Pipeline’ sections that
are greyed out. Depending on the user selection in SOUR OPERATIONS
TYPE, ERCBH2S does not require all of the inputs within a given section.
10. Within each of the three sour operations sections (GAS PIPELINE, GAS
WELL and LIQUID PIPELINE/WELL), there is a sub-section titled
SOURCE MITIGATION.
SOURCE MITIGATION choices reflect very specific valves and/or
operational settings, along with licensee ‘action’ commitments for reducing
source duration for improved hazard management. Short, smaller amounts
3 Quick-Start
19
of hydrogen sulphide released to the atmosphere equates to a smaller hazard
which equates to smaller ERP zones.
Access to this sub-section is controlled by the user selection for
ANALYSIS TYPE.
11. Locate ANALYSIS TYPE within ADMINISTRATIVE.
Toggle between, NO MITIGATION and WITH MITIGATION and
observe how the display changes within the sour operations group selected.
12. You may have observed that the final two sections of the INPUTS page are
always available for user input.
These two sections are discussed in more detail in other tutorials, and in
Chapter 5 of the ERCBH2S User Guide under Sour Gas Composition and
Advanced User Selected Case.
13. Using the page tabs at the bottom of the screen, select the ERP
SUMMARY page.
The first part of this page to observe is the upper portion – the part above
the title ‘RESULTS’ (in row 36).
The first part of the ERP SUMMARY page is a summary of all of the
inputs related to whatever sour operations type is selected on the INPUTS
page.
If you toggle back to the INPUTS page and change the sour operations
type, the ‘inputs display’ portion of the ERP SUMMARY changes too - it
always displays whatever is currently ‘active’ on the INPUTS page.
14. The ERP SUMMARY page also provides a graphic and tabular summary
of the ERP zones calculated, along with a table describing applicable landuse setback information and certain other details. This information is
3 Quick-Start
20
displayed on the lower part of the page below the title ‘RESULTS’ (in
row 36).
At any given time, there is only one set of calculation
results (outputs) shown on the lower part of the ERP
SUMMARY page. If these results don’t ‘match’ the inputs
on the upper part of the page, a red flag appears at the
top and bottom of almost every ERCBH2S page, including
the ERP SUMMARY page.
For the tutorial example, a red flag can be removed by returning to the
INPUTS page and selecting the SOUR OPERATIONS TYPE ‘LIQUID
PIPELINE/WELL’ and the ANALYSIS TYPE ‘WITH MITIGATION’.
This example input file already received the program ‘run’ command
‘Calculate EPZ’ - therefore these are the calculation results shown at the
bottom of the ERP SUMMARY page.
15. Return to the INPUTS page. To complete the calculations required for
submission to the ERCB you will run a new example file:
Select GAS PIPELINE for the Sour Operations Type.
Select NO MITIGATION for the Analysis Type.
Go to row 13 and change SCENARIO NAME to ‘Scenario 4’.
Observe that these changes caused a red flag to appear at the top of the
page (because the inputs no longer match the calculation results or
‘outputs’).
Select Calculate EPZ from the ERCBH2S menu item, or select
the button bar.
on
As part of the ERP zones’ calculation sequence, the ERCBSLAB program
(among other things) runs a total of 594 times for a pipeline. The program
searches for the worst gas pipeline release ‘failure size’ (the hole size
fraction exit area ratio – there are 11 of them) that produces the largest
hazard zone for each of 54 different meteorological conditions
(combinations of wind speed, atmospheric stability class) to get 54
different worst-release hazard distances. The weighted-averaged value of
these 54 distances is calculated by multiplying the hazard distance in each
of the 54 categories by the fraction of time that each meteorological
condition occurs.
3 Quick-Start
21
It may take several moments to complete the calculations depending on the speed of your computer. Pipeline
calculations take longer than wells because where pipeline a
pipeline calculation runs 11 x 54 times (594 times), a well
runs only 54 times.
16. When the calculations are completed, the ERCBH2S program displays the
ERP SUMMARY page. Review the results. If there is a red flag at the
top and bottom of the page, the calculation results are invalid for ERCB
submission.
Never use predicted ERP zones or include the ERP
SUMMARY page printout in your ERP if a red flag
appears at the top and bottom of the ERP SUMMARY
page.
If a printout is required, use the printer icon
, in the ERCBH2S buttonbar. The ERP SUMMARY page will be sent to your default printer.
Now you will create the export file required for ERCB submission, by first
saving the completed scenario to the BATCH page.
3 Quick-Start
22
17. Return to the INPUTS page. Go to ‘ERCBH2S’ on the menu-bar, select
‘Batch’, then select ‘Save INPUTS and Results to Batch Page’.
Alternatively, select the Save INPUTS and Results to Batch Page
command
from the button-bar.
Select the BATCH page tab at the bottom of the screen. Notice that the
BATCH page has four records (rows) on it. There were already three
completed records in it when you opened the Quick-Start tutorial file, and
you just added another one.
Each row on the BATCH page represents a column of user inputs (from
column C on the INPUTS page), and calculation results that correspond to
those inputs. The BATCH page is very large and can hold hundreds of
scenarios of all different sour operations types.
It is the electronic copy of the BATCH page a licensee/applicant is required
to submit to the ERCB. Make a habit of scrolling over to column DO to
verify that there is no error messages (red flags) listed before you create
the export file for submission.
3 Quick-Start
23
18. Go to ‘ERCBH2S’ on the menu-bar, select ‘Technical’, then select
‘Batch Export’.
A prompt will appear for you to name the export file. The ERCB requires
licensees/applicants to use the following file naming protocol:
BA code - ERP Plan Ref# - Date (DD/MMM/YY)
For example, if a company with the BA code of WXYZ submits a file on
July 5th, 2008, the file would be named:
WXYZ-1234-05Jul08.csv
The .csv file extension - ‘comma separated variable - is automatically
attached to the file name. This is the file required for ERCB submission.
The .csv file does not contain user information added to the NOTES page.
19. OPTIONAL Return to the INPUTS page. Select other combinations of
sour operations type and with/without mitigation, or try changing required
numerical inputs. After making some changes, selecting Calculate EPZ
will activate the required calculation sequence, and a revised ERP
SUMMARY page will be displayed.
20. OPTIONAL How does ERCBH2S perform all of these predictions? To
see the more detailed intermediate calculation pages and results, the user
can select a different ‘view’ – the technical view.
Return to the INPUTS page, and go to the menu item
ERCBH2S→Setup→Hide Technical Sheets. With ‘hide technical
sheets’ checked, the detailed calculation pages are hidden, and only certain
3 Quick-Start
24
pre-selected input and output pages are displayed and menu-bar buttons are
active. This is considered a ‘typical view’.
Click to remove the check-mark and observe that many more page tabs are
displayed at the bottom of the screen. Visit the pages and view the
displayed information. This is considered a ‘technical view’.
Most users prefer the ‘typical view’, because it provides the necessary
information to determine the ERP zones. However, some ERP Planners
may choose the ‘technical view’ to better understand the hazards and how
they can be mitigated at the source.
21. OPTIONAL Return to the INPUTS page, and go to the menu item
ERCBH2S→About ERCBH2S. The following window box will
appear:
This provides the information about the program and the version numbers.
By clicking on the OK button, the macros are reset and the display
disappears.
3 Quick-Start
25
22. Exit without saving (to prevent over-writing the Quick-Start tutorial
file).
Now that you have run the Quick-Start tutorial you can learn more about the
inputs, calculations, outputs, batch processing, and try a few more examples.
To continue working with the ERCBH2S program, the next chapter to review is
Chapter 5 – Inputs. This chapter provides detailed instruction for what to enter
(and what not to enter) into the ERCBH2S INPUTS page. Until a user is well
acquainted with ERCBH2S, Chapter 5 should always be referenced when
completing the INPUTS page.
Until a user is well acquainted with ERCBH2S, Chapter 5
should always be referenced when completing the
INPUTS page.
3 Quick-Start
26
4.
Program Operation
This chapter provides the following information about the general operation of the
ERCBH2S program:
•
what the principal files are and how they work together
•
what the buttons/menu items do
•
overview of the calculation processes
•
importing and exporting model inputs
•
printing the results
Introduction
The ERCBH2S program uses the familiar Microsoft Excel as host for the
calculations. The ERCBH2S application consists of two parts
•
ERCBH2S.xla program (the macros and detailed calculations with links to
the dynamic link library - .dll), and
•
ERCBH2S-INPUTS.xls.
To run the ERCBH2S program, both the ERCBH2S.xla
program and an ERCBH2S – INPUTS.xls file must be open.
If the ERCBH2S application is configured as an Add-in for
automatic loading when Excel is started, it is not necessary
to open both the .xla and .xls files each time. ERCBH2S.xla
will open automatically every time an .xls file is opened.
See Activating the ERCBH2S Add-In in Chapter 2.
ERCBH2S.xla is a set of macros and programming that runs as a Microsoft Excel
add-in (an application that runs within Excel, adding extra functions and
capabilities). One of its many functions is linking to the .dll program files.
Dynamic link library files (.dll) are program files loaded into your
computer when ERCBH2S is installed. These programs; ERCBSLAB,
and ERCBFLASH are accessed (linked) via ERCBH2S.xla.
4 Program Operation
27
ERCBH2S-INPUTS.xls contains the user-interface for the calculations, allowing
the user to input information and view calculation results.
ERCBH2S-INPUTS.xls is an Excel spreadsheet file (.xls)
that acts as a template file for the ERCBH2S application.
All inputs and outputs are stored within the ERCBH2SINPUTS. xls template file. Although technical debugging
files are stored in separate text files in the same directory as
the ERCBH2S template file, most users do not require using
these extra text files.
User-Interface
Overview – The ERCBH2S Template file in Excel
All user input and output are controlled using an ERCBH2S template file for
Microsoft Excel. The template file (.xls) contains several Excel worksheets
(pages). While user inputs for the ERCBH2S calculations are on a single page,
calculations and outputs are displayed on several pages - all within the same
template file.
You may use either a template (blank) or example file
to build your release scenario. It is recommended that
you create a new folder for your scenario files. It is
also recommended that you create a file naming
convention for your scenario files to avoid over-
writing the ‘pre-packaged’ blank template or example
files. Following this advice allows the user to create new
projects from the same known starting point.
If you accidentally overwrite the blank template or example
files, you can re-install them by
1. re-naming the existing template and example files;
and
2. re-running the install program to re-install selected
components.
4 Program Operation
28
Within the single blank template or example file (both ‘.xls’ files), initial user
selections on the INPUTS page lead to one of three sour operation ‘types’ (or
‘flavours’):
1.
GAS PIPELINE. Used to model gas pipeline releases. A gas
pipeline release has a transient flow rate (transient jet).
2.
GAS WELL. Used to model gas well releases. A gas well
release has a steady in flow rate (steady jet).
3.
LIQUID PIPELINE OR LIQUID WELL. Used to model
liquid releases from pipelines or wells. A liquid release creates a
pool of liquid on the ground, with the sour gas rapidly coming
out of solution. The release has a steady flow rate (steady jet).
ERCBH2S calculation process differs for each of the sour operation types.
Processes details are described later in this chapter under Calculation Process.
The ERCBH2S Excel Pages
ERCBH2S has the following four types of pages in the Excel user interface – each
category identified by name and page tab colour (for Office 2002 and newer
versions of Excel only):
USER INFORMATION
ERCB contacts, brief instructions and error code descriptions, and
a blank page for user ‘notes’. (Blue page tabs)
INPUTS
Prompts and data entry boxes for user specified values for the
ERCBH2S models. (Green page tabs)
TECHNICAL/CALCULATION (INTERMEDIATE)
Intermediate steps in the modelling process: for the input into
ERCBSLAB or ERCBFLASH; and for post-processing of the data
into a user-friendly format. Calculations are divided between
Excel (the user can view these calculations within Excel) and
compiled code programs, ERCBSLAB, and ERCBFLASH (the
equations used in these programs are described in the Technical
Reference Document and in the USEPA SLAB User Guide).
(Yellow page tabs)
SUMMARY GRAPHICS (OUTPUT)
Output information summarized in both tabular and graphical
form. (Pink page tabs)
4 Program Operation
29
Tabs for the page types are colour coded for Office 2002
and newer versions of Excel (earlier versions do not display
the page colours).
User information pages are blue, input pages are green,
calculation pages are yellow, and output pages are pink.
Recall that the ERCBH2S model uses an industry standard
model (US EPA SLAB model), modified to perform
additional calculations. The input / output format used by
the ERCBH2S model is adapted from the USEPA SLAB
model. ERCBH2S reconfigures the user-specific inputs into
the proper format for the ERCBH2S model.
A complete list of user-interface pages are described in the following table:
4 Program Operation
30
Page Name
Purpose
ABOUT
User
Information
ERROR CODES
User
Information
NOTES
User
Information
BATCH
View
Typical
Technical
Description
General information and instructions for use of the spreadsheet and
submission of the results to the ERCB. Use this sheet to link to the latest
information regarding ERCBH2S.
Error code listing. Consult this sheet to interpret error codes.
A formatted sheet for the User to record details about the inputs.
Input
and Results
User input for batch processing (multiple scenarios in a single file) and
pipeline gathering system plus summary of results.
INPUTS
Input
User input for administrative, facility, mitigation and sour gas composition
data.
CONSTANTS
Input
SHARED
Calculation
ERCBFLASH
Calculation
ERCBFLASH OUTPUT
Read Only Data
ERCBSLAB
Calculation
ERCBSLAB OUTPUT
Read Only Data
TOX OUTPUT
Read Only Data
MAX OUTPUT
Read Only Data
ERP SUMMARY
Output
HAZARDS
Tabular
Summary
ERCB default inputs, not editable.
Includes calculations of chemical/physical properties and gas composition
that are common to all ERCBH2S analysis flavours, not editable
ERCBFLASH input variables are created from the calculations on other
pages.
Output variables from ERCBFLASH.
ERCBSLAB input variables are created from the calculations on other
pages.
Variables from ERCBSLAB. Selected values from this page are graphed on
the GRAPH-ERCBSLAB(x).
Predictions from ERCBSLAB for user selected case. Provides
concentrations and toxic load-equivalent concentrations as a function of
down wind distance. Data from this page are graphed on the GRAPHTRANSIENT EVENT (X) or GRAPH-STEADY EVENT (X).
Maximum of predictions from ERCBSLAB for all screening cases. Provides
concentrations and toxic load-equivalent concentrations as a function of
down wind distance. Data from this page are graphed on the GRAPHTRANSIENT EVENT (X) or GRAPH-STEADY EVENT (X).
Summary of Inputs and Emergency Response and Planning Zones. This
page to be included for each well and pipeline segment in the Emergency
Response Plan.
Summary of Release Description, User Selected Case Hazard Distances,
Maximum of Screening Hazard Cases ERP Zones.
GRAPH-MET
Graphic
Summary
Tabular and graphical representation of the METMATRIX data. Hazard
distances for the range of meteorological conditions and wind speeds.
Presented in tabular and graphical format. The maximum computed
distance is highlighted.
GRAPH-ERCBSLAB(x)
Graphic
Summary
Graph showing how variables change as the release moves away from the
source.
METMATRIX
Tabular
Summary
Hazard distances for the Screening Matrix of 54 different stability class /
wind speed combinations.
HAZARD DISTANCES
Tabular
Summary
Calculates worst-release with worst-dispersion distance and worst-release
with averaged-dispersion distance.
SOUR GAS PIPELINE flavour
SOUR GAS PIPELINE
Calculation
Calculates inputs to ERCBFLASH and uses output from ERCBFLASH to
calculate inputs to ESD CLOSURE and ERCBSLAB.
ESD CLOSURE
Tabular
Summary
Intermediate calculation page to determine ESD valve closure time for the
input settings for the user selected AeAp.
AeAp-ITERATION
Tabular and
Graphic
Summary
Intermediate calculation page to determine the pipeline source exit area to
pipeline area that leads to the largest ERP Zones
GRAPH-TRANSIENT
EVENT(x)
Graphic
Summary
Graphical representation of the TOX OUTPUT and MAX OUTPUT
concentrations. The Planning and Alert Criteria are highlighted on the graph
4 Program Operation
31
View
Typical
Technical
SOUR GAS WELL flavour
Page Name
Purpose
Description
SOUR GAS WELL
Calculation
Calculates inputs to ERCBFLASH and uses output from ERCBFLASH to
calculate inputs to ERCBSLAB.
GRAPH-STEADY
EVENT(x)
Graphic
Summary
Graphical representation of the TOX OUTPUT and MAX OUTPUT
concentrations. The Planning and Alert Criteria are highlighted on the graph
SOUR LIQUID PIPELINE/WELL flavour
SOUR LIQUID
Calculation
Calculates inputs to ERCBFLASH and uses output from ERCBFLASH to
calculate inputs to ERCBSLAB.
GRAPH-STEADY
EVENT(x)
Graphic
Summary
Graphical representation of the TOX OUTPUT and MAX OUTPUT
concentrations. The Planning and Alert Criteria are highlighted on the graph
Hidden Technical Pages
All ERCBH2S Excel pages (sheets) are available in the blank template or example
files. Because most users require only a few of the pages, the blank template and
example files open with most of the technical pages ‘hidden’. This is referred to
as the ‘typical view’. The typical view displays five page tabs – ABOUT,
NOTES, BATCH, INPUTS and ERP SUMMARY. Most users prefer the
typical view because it provides the necessary information to determine the ERP
zones.
Some ERP Planners prefer access to all ERCBH2S Excel pages to better
understand the hazards and how they can be mitigated at the source. This view is
referred to as the ‘technical view’. To access this view, from the INPUTS page
the user must go to the menu item ERCBH2S→Setup→Hide Technical
Sheets. With ‘hide technical sheets’ checked, the detailed calculation pages are
hidden, and only five pre-selected input and output pages are displayed (the
typical view).
4 Program Operation
32
With the check-mark ‘clicked’ for removal, all the ERCBH2S Excel page tabs are
displayed at the bottom of the screen. This is the technical view.
For users choosing the technical view, a copy of the
ERCBH2S User-Interface Page Guide will provide handy
reference (previous section).
Excel Functionality
The ERCBH2S user-interface was developed within Excel to provide a relatively
common platform for most technical users. The Excel spreadsheet also provides a
transparent implementation of the model as opposed to compiled code. Because
Excel is used as the interface, much of the Excel functionality is retained within
the ERCBH2S program. That is, user input boxes can accept numeric or text
information, as well as calculations including Excel function calls.
Using function calls, a technical user can link input cells
(such as on the BATCH page, see page 117) to other
spreadsheets.
Information can be copied to and from the template files using standard Excel
methods, such as the Cut, Copy and Paste edit commands.
The ERCBH2S program template spreadsheets include
security protection on non-user-input cells and pages. You
will not be able to Cut or Paste to these cells.
ERCBH2S Excel Menus
The ERCBH2S application menu is added to the main menu-bar for Excel when
the ERCBH2S application is loaded using the Add-in Manager or when the XLA
file is opened using File→Open→ERCBH2S.xla. The ERCBH2S application
menu is shown below. These options link to the principal ERCBH2S program
operations.
4 Program Operation
33
BUTTON
DESCRIPTION
Run the ERCBSLAB calculation for the
inputs on the INPUTS page for the user
selected wind speed, meteorological stability
and exit area ratio.
Run the ESD Closure calculation for the gas
pipeline entries on the INPUTS page
Run the Ae/Ap Ratio Search (exit area
ratio) for the gas pipeline entries on the INPUTS
page for the user selected wind speed and
meteorological stability.
Calculate EPZ for the inputs on the
INPUTS page to determine the ERP zones for
all wind speeds, meteorological stabilities and
(for sour gas pipelines) exit area ratio and ESD
timing.
Print the ERP SUMMARY page.
Many selections shown under menu item ERCBH2S (and some of the sub-menu
items) also appear as ‘Buttons’ on the ERCBH2S Button-bar.
Technical Submenu
The Technical submenu is shown below with a description of the menu items.
These operations are provided for the technical user or for operations debugging.
These operations allow the user to complete individual program steps
(ERCBFLASH and ERCBSLAB) as described below.
4 Program Operation
34
BUTTON
Run ERCBFLASH Only…
Run ERCBSLAB Only…
DESCRIPTION
Runs the ERCBFLASH calculations for the
current model configuration
Runs ERCBFLASH and then runs the
ERCBSLAB calculations for the current model
configuration and the current ERCBFLASH
output information
Erase all output fields in the template
spreadsheet file (does NOT erase output data
stored on the BATCH page).
Erase all input fields on the INPUTS page (does
NOT erase input data stored on the BATCH
page)
Imports a BATCH export file to the BATCH
page.
Exports a BATCH import file (input and ERP
SUMMARY Results) with data stored on
BATCH page.
Batch Submenu
The BATCH submenu is shown below with a description of the menu items. The
BATCH page is very large and can hold hundreds of scenarios of all different
sour operations types. BATCH operations assist in loading and saving
information from the INPUTS page. While ERP zone calculations can be done
directly from the BATCH page, information can be moved back and forth
between the BATCH page and INPUTS page. Other menu items are for
selecting run-time functions for testing or full processing.
4 Program Operation
35
ERCB Submission Requirements – Licensees/applicants are required to
submit an electronic copy (export file) of the BATCH page for the subject
submission. Details about the BATCH page (including the ERCB file naming
protocol) are in Chapter 8 - Batch Page.
BUTTON
DESCRIPTION
INPUTS page is active: Saves
parameters from the INPUTS page and results
to a new line (row) on the Batch page, or
overwrite an existing record with the same
Scenario Name.
BATCH page is active: Copy the
selected INPUT record from the BATCH page
to the INPUTS page (calculation results are
NOT brought over to the ERP SUMMARY
page).
INPUTS page is active: Fetch the first
record on the BATCH page to the INPUTS page
(calculation results are NOT brought over to the
ERP SUMMARY page).
INPUTS page is active: Fetch the
previous record on the BATCH page to the
INPUTS page. The previous record is ‘above’
the record with the “Scenario Name” that
matches what is currently displayed on the
INPUTS page (calculation results are NOT
brought over to the ERP SUMMARY page).
4 Program Operation
36
INPUTS page is active: Fetch the
next record on the BATCH page and read
(copy) the records to the INPUTS page. The
next record is ‘below’ the record with the
“Scenario Name” that matches what is currently
displayed on the INPUTS page (calculation
results are NOT brought over to the ERP
SUMMARY page).
INPUTS page is active: Fetch the last
record on the BATCH page to the INPUTS page
(calculation results are NOT brought over to the
ERP SUMMARY page).
Batch Run ERCBSLAB for each record
marked RUN on the BATCH page. This is a
‘test run’ and is not sufficient for ERCB
submission – user must run the Batch
Calculate EPZ calculation for ERCB
submission.
Batch Calculate EPZ calculates ERP
Zones for each record marked RUN on the
BATCH page.
Check for Scenario Duplicates
Check the scenario name of each record on the
BATCH page for duplicate names.
Setup Submenu
The Setup submenu is shown below with a description of the menu items.
4 Program Operation
37
BUTTON
Hide Technical Sheets
ERCBSLAB debug
Silent Start
DESCRIPTION
This toggle switch hides/shows the technical
calculation pages (typical or technical view). Most
users will not require viewing of the technical sheets.
This toggle switch is used to turn on/off the creation of
text output file generation of the output from the
ERCBSLAB model to the current working folder.
This toggle switch is used to turn off/on the
confirmation prompts for when BATCH calculations
are about to be performed, and suppresses error
message dialog pop-ups. This switch is useful when
automating BATCH processes.
ERCBH2S Excel Button-Bar
The ERCBH2S application button bar is added to the Excel window when the
ERCBH2S application is loaded using the Add-in Manager or when the XLA file
is opened using File→Open→ERCBH2S.xla. The ERCBH2S application
button bar (shown below) displays principal commands for ERCBH2S program
operation. All of the buttons are also listed as choices under ERCBH2S in the
menu-bar.
BUTTON
DESCRIPTION
Print the ERP SUMMARY page.
Erase all output fields in the template spreadsheet file
(does NOT erase output data stored on the BATCH
page).
INPUTS page is active: Save INPUTS and
Results to a new line (row) on the Batch page, or
overwrite an existing record with the same Scenario
Name.
BATCH page is active: Copy the selected
record from the BATCH page to the INPUTS page
(calculation results are NOT brought over to the ERP
SUMMARY page).
INPUTS page is active: Fetch the first
record on the BATCH page to the INPUTS page
(calculation results are NOT brought over to the ERP
SUMMARY page).
4 Program Operation
38
INPUTS page is active: Fetch the previous
record on the BATCH page to the INPUTS page. The
previous record is ‘above’ the record with the
“Scenario Name” that matches what is currently
displayed on the INPUTS page (calculation results are
NOT brought over to the ERP SUMMARY page).
INPUTS page is active: Fetch the next
record on the BATCH page and read (copy) the
records to the INPUTS page. The next record is
‘below’ the record with the “Scenario Name” that
matches what is currently displayed on the INPUTS
page (calculation results are NOT brought over to the
ERP SUMMARY page).
INPUTS page is active: Fetch the last record
on the BATCH page to the INPUTS page (calculation
results are NOT brought over to the ERP SUMMARY
page).
‘Test run’ the BATCH page inputs. This command
runs the ERCBSLAB calculation for each record
marked RUN on the BATCH page. This is not
sufficient for ERCB submission – user must run the
Batch Calculate EPZ calculation for ERCB
submission.
Run the Batch Calculate EPZ calculation for
each record marked RUN on the BATCH page.
Run the ERCBSLAB calculation for the inputs on
the INPUTS page for the user selected wind speed,
meteorological stability and exit area ratio.
Run the ESD Closure calculation for the gas
pipeline entries on the INPUTS page
Run the Ae/Ap Ratio Search (exit area ratio) for
the entries on the INPUTS page for the user selected
wind speed and meteorological stability.
Run the Calculate EPZ for the inputs on the
INPUTS page to determine the ERP zones for all wind
speeds, meteorological stabilities and (for sour gas
pipelines) exit area ratio and ESD timing.
Note that as you move your cursor across the button-bar that active buttons are
framed and in colour. If the button is inactive, it will appear gray in colour. The
activity depends on the Sour Operations Type, if the technical sheets are hidden or
what sheet is active.
4 Program Operation
39
Saving Scenarios as Excel Files
ERCBH2S scenarios are saved as Excel files. It is recommended that you save
scenarios with a logical description, such as the pipeline segment name or
scenario name. Remember not to overwrite the original blank template file. This
ensures new scenarios have consistent ‘starting data’ to help minimize calculation
problems.
If using the ERCBH2S ‘Gathering System Analysis’ feature on the BATCH page
(Chapter 9 - Pipeline Gathering Systems), refer to the suggested scenario naming
format in Chapter 9 under Pipeline Segment Label (Scenario Name).
Unless saving a BATCH file for ERCB submission needs, it is recommended that
you choose another file naming convention. The required file naming protocol
for ERCB submissions is described in this chapter under Importing and Exporting
ERCBH2S Batch Files.
To save a scenario file:
1. Click File in the menu-bar and select Save As.
2. Create a file name for your scenario and click the Save button. This
method of file saving also stores any information added to the NOTES
page.
You are not restricted in your selection of folder in which to
save your scenario files. It is recommended that you create
a new folder and naming convention to store related
scenarios.
You may also use the BATCH Page (see page 117) to
store multiple scenarios or sensitivity tests within a single
file.
Importing and Exporting ERCBH2S BATCH Page
The input and certain key ERP output data stored on the BATCH page can be
exported to an ERCBH2S export file for convenient email transfer or backup.
From the menu-bar, ERCBH2S→Technical→ Batch Export... prompts the
user using common windows file dialog window for a folder and a file name.
4 Program Operation
40
For ERCB submissions, licensees/applicants are required to use the following
file naming protocol:
BA code - ERP Plan Ref# - Date (DD/MMM/YY)
For example, if a company with the BA code of WXYZ submits a file on July 5th,
2008, the file would be named:
WXYZ-1234-05Jul08.csv
The .csv file extension (comma separated variable) is automatically attached to
the file name. The variable names are those expected by ERCBH2S to match the
INPUTS page - the order of the variables in the file is not important.
The batch export file can be viewed using Excel or Notepad or other text
editor. Note that the .csv file does not contain user information added to the
NOTES page.
An ERCBH2S batch export file can be reloaded to a BATCH page using the
batch-import function ERCBH2S→Technical→Batch Import... from the
menu bar.
BATCH page submissions to the
ERCB must not have any error
codes in column DO!
An example .csv export file is provided in the listing below.
4 Program Operation
41
ERCBH2S File Version,1
ERCBH2S Version, 1.2
ERCBH2S Spreadsheet Version,1.21.0002
ERCBH2S Macro Version,1.21.0002
ERCBSLAB Version, 001.002.0001
ERCBFLASH Version, 001.000.0001
[START ------------------------------------------- ]
Admin_BAcode,A
Admin_Licensee,B
Admin_Address,C
Admin_City,D
Admin_PostalCode,E
Admin_ContactName,F
Admin_Phone,G
Admin_Fax,H
Admin_eMail,I
Calc_ScenarioName,Label 3 Gas Well
Calc_SubstanceType,1
Calc_AnalysisType,1
Admin_FacilityName,Label 1
Admin_FacilityLicense,K
Admin_SurfaceLocation,Label 2
Admin_SurfaceLocation_Start,M
Admin_SurfaceLocation_End,N
Admin_Elevation,1000
Admin_EPZExisting,na
Admin_Datum,7
Pipeline_StartX,O
Pipeline_StartY,P
Pipeline_EndX,Q
Pipeline_EndY,R
Pipeline_MOP,9930
Pipeline_Pressure,5000
Pipeline_OutsideDiameter,273.1
Pipeline_WallThickness,9.3
Pipeline_SegmentLengthActual,1000
Pipeline_EquivalentLength,5420
Pipeline_EquivalentVolume,
Pipeline_GOR,
Pipeline_H2SMax,14
Pipeline_H2SConcentration,7
Pipeline_Ti,
Pipeline_ESDTclose,
Pipeline_ESDPressureTrigger,
Pipeline_ESDPROCTrigger,
Pipeline_ESDTpoll,
Pipeline_TESDManual,
Pipeline_TimeBeforeMitigation,
Well_Phase,2
Well_IsCritical,1
Well_UniqueWellIdentifier,O
Figure 1: Export/Import CSV file sample
4 Program Operation
42
ERCBH2S Excel Print Settings
Each page has been paginated for proper display of the data on Letter size paper
(North American, 8.5in ×11in or 216mm×279mm). Any page may be printed by
clicking the standard Excel print icon.
The ERCBH2S→PRINT REQUIRED command,
ERP SUMMARY page to the default printer.
, automatically sends the
ERCBH2S Excel Pages – RED FLAG WARNINGS
A red flag warning appears as a banner at the top of many ERCBH2S Excel
pages when user inputs are missing, outside of allowable ranges, or have changed
since the last calculation sequence was performed. It is important to
remember that at any one time, there is only one current set of calculation results
displayed on the ERCBH2S Excel pages (other than the BATCH page, which can
store many different sets of calculation result records). Red flag warnings are
described in detail under Red Flag Warnings in Chapter 5.
The ERCBH2S Calculation Process
Calculations are controlled by the ERCBH2S.xla application file. All user input,
intermediate calculations and output displays are done in the ERCBH2S template
file for Microsoft Excel, ERCBH2S-INPUTS.xls. Major calculations are done
in the dynamic link library programs (dll) as directed by ERCBH2S.xla.
Run ERCBSLAB
There are eight steps in the basic calculation process known as Run
ERCBSLAB with the button
, as described below and shown in the flow
diagram that follows:
1.
Basic information about the scenario Flavour and release description are
entered on the INPUTS page. The user then presses the
ERCBH2S→ERCBSLAB command to start the sequence of calculations.
2.
Intermediate calculations are immediately performed by Excel when data
changes on the INPUTS page. Depending on the scenario Flavour,
calculations are performed on one of the SOUR GAS PIPELINE, SOUR
4 Program Operation
43
GAS WELL or SOUR LIQUID pages. The intermediate calculations
prepare a model input file for the ERCBFLASH program.
The model input file is listed on the ERCBFLASH page. The input file is
compared to the previous input file for ERCBFLASH. If the input is the
same as the previous file, the ERCBFLASH is not required to be executed
again, and the results from the previous run are still valid. In this case, the
ERCBH2S program calculations will continue at step 4. If the input file is
new, then the calculations continue at Step 3.
3.
After the ERCBFLASH program has completed its calculations of real gas
properties for the gas composition and physical parameters input, output
data is displayed on the ERCBFLASH OUTPUT page. The ERCBH2S
program resumes the calculation process.
4.
Intermediate calculations then proceed on either the SOUR GAS
PIPELINE, SOUR GAS WELL or SOUR LIQUID pages depending on
the scenario flavour, using the real gas properties calculated by the
ERCBFLASH program for the physical conditions entered in the INPUTS
page.
5.
Intermediate calculations are performed by Excel on either the SOUR GAS
PIPELINE, SOUR GAS WELL or SOUR LIQUID pages to calculate
source parameters for dispersion modelling using the ERCBSLAB program.
The intermediate calculations prepare a model input file for the ERCBSLAB
program.
The model input file is listed on the ERCBSLAB page. The input file is
compared to the previous input file for ERCBSLAB. If the input is not the
same as the previous file, the red flag may appear, indicating that the
previous results are invalid. Different than the ERCBFLASH process, the
ERCBH2S program will always re-run the ERCBSLAB program when the
Run ERCBSLAB command is used.
4 Program Operation
44
6.
After the ERCBSLAB program has completed its dispersion calculations for
the real gas properties and physical parameters input, output data is
displayed on the intermediate calculation technical ERCBSLAB
OUTPUT and TOXOUT pages.
7.
The Intermediate calculations then proceed on the GRAPH-ERCBSLAB
(x), GRAPH-TRANSIENT(x), or GRAPH-STEADY(x) pages,
depending on the scenario flavour. These pages display the technical
intermediate calculation results in a graphical format. Each of these graphs
display information as a function of downwind distance or x-distance.
8.
After the ERCBSLAB program has completed its dispersion calculations for
the parameters input, output data is displayed on the intermediate
calculation technical MET MATRIX page.
The final results of the calculations are displayed on the HAZARD
DISTANCES page, in the form of a table. The table lists the calculated
Worst-Release Hazard Distance for the meteorological stability class, wind
speed and exit area ratio on the INPUT page.
4 Program Operation
45
Gas Well Calculation Process
There are two basic flow sequences for the WELL flavour as shown in the
following calculation flow graphic. The basic ‘once through’ Run ERCBSlab
sequence (A) is a single iteration of the overall calculation process as shown
in the preceding graphic. The calculation is performed using the single
meteorological stability class and wind speed entered on the INPUTS page.
A series of calculation processes is performed for the Calculate EPZ
command to iterate automatically to calculate the Dispersion Condition
Probability Weighted Hazard Distances. The calculation process is shown as flow
pattern (B) in the following graphic. The overall process is similar to the process
(A), except that the ERCBSLAB calculations are repeated many times to calculate
the Worst-Release Hazard Distances for different meteorological stability class
and wind speed. The iteration process in (B) is repeated 54-times for the various
combinations of meteorological conditions and results 54 Hazard Distances. The
dispersion condition probability weighted value of these 54 distances is calculated
by multiplying the hazard distance in each of the 54 categories by the fraction of
time that each meteorological condition occurs, and results the Worst-Release
with Averaged-Dispersion Hazard Distances. The final results of the calculations
are displayed on the HAZARD DISTANCE page, in the form of a table.
For the detailed technical description of the calculations and methods used in the
programs see Volume 1 - Technical Reference Document Version
1.20.
4 Program Operation
46
FLAVOR
FLAVOR
GAS WELL & LIQUID GAS WELL & LIQUID
PIPELINE/WELL
PIPELINE/WELL
INPUTS
INPUTS
Run ERCBSLAB
CALCULATE EPZ
User Selected
Wind speed
Stability Class
Ae/Ap Ratio
ERCB_FLASH.dll
ERCB_FLASH.dll
ERCB_SLAB.dll
TOX output
Loop for new wind
speed and stability
ERCB_SLAB.dll
TOX output
ERCBSLAB output
GRAPHS
The results reflect the userselected meteorological stability,
windspeed, and Ae/Ap ratio
A
4 Program Operation
ERCBSLAB output
GRAPHS
Worst-release Hazard Distance
for 54 meteorological conditions
Dispersion condition
Probability Weighted
Distances
B
47
Liquid Pipeline and Liquid Well Calculation Process
There are also two basic flow sequences for the LIQUID flavour. The
parameters are entered for the LIQUID flavour on the INPUTS page and
intermediate calculations are provided on the technical LIQUID page. The
LIQUID calculation process is the same as the WELL calculation process
illustrated as process (A), and (B) in the above graphic.
Gas Pipeline Calculation Process
There are three basic flow sequences for the PIPELINE flavour as shown in the
following calculation flow graphic. The basic ‘once through’ sequence (C) is a
single iteration of the overall calculation process, already described in Run
ERCBSLAB. The calculation is performed using the selected meteorological
stability class, wind speed and pipeline exit area ratio entered on the INPUTS
page.
For the PIPELINE Flavour, a release and the calculated downwind
concentrations are a function of the hole size, which is expressed as the exit area
to pipeline area ratio (Ae/Ap). Ae/Ap ratios vary from 0.01 (a small hole) to 2.00
(the pipeline is severed in two). Ae/Ap ratio affects the rate and duration at which
sour gas is released from the pipeline and input to ERCBSLAB.
For large Ae/Ap ratio, the release is a suddenly large cloud of gas with a short
duration. For small Ae/Ap ratio, the release is long duration and relatively
steady in release rate. Often the intermediate release holes can produce the largest
ERP zones. To assist in the search for the worst release exit area ratio, the
ERCBH2S program has been automated to repeat the overall calculation process
for a range of hole size ratios. The calculation process is represented as the flow
pattern (D) in the following graphic. The Worst-Release Hazard Distance is
estimated based on the iteration for exit area ratio using the selected
meteorological stability class and wind speed entered on the INPUTS page. The
results are listed on the METMATRIX page (Hazard Distances for
Meteorological Matrix).
A third calculation process is performed for the PIPELINE flavour, to iterate
automatically to use the Worst-Release condition (the exit area ratio that produces
the largest hazard zone) for each of different meteorological conditions to get
different Worst-Release Hazard Distances. The calculation process is shown as
flow pattern (E) in the following graphic. The overall process is similar to the
process (D), except that the ERCBSLAB calculation is repeated many times for
different meteorological and release conditions. The iteration process in (E) is
4 Program Operation
48
repeated 54-times for the various combinations of meteorological stability and
wind speeds and 11-times for each of the exit area ratios.
For the detailed technical description of the calculations and methods used in the
programs see Volume 1 - Technical Reference Document Version
1.20.
FLAVOR
FLAVOR
FLAVOR
GAS PIPELINE
GAS PIPELINE
GAS PIPELINE
INPUT
INPUT
INPUT
Run ERCBSLAB
Ae/Ap ITERATION
CALCULATE EPZ
User Selected
Windspeed, Stability
Class, Ae/Ap Ratio
User Selected
Windspeed, Stability
Class, Ae/Ap Ratio
User Selected
Windspeed, Stability
Class, Ae/Ap Ratio
ERCB_FLASH.dll
ERCB_FLASH.dll
ERCB_FLASH.dll
EDS Closure Timing
EDS Closure Timing
2
EDS Closure Timing
ERCB_SLAB.dll
ERCB_SLAB.dll
TOX output
ERCBSLAB output
TOX output
ERCBSLAB output
GRAPHS
The results reflect the userselected meteorological stability,
windspeed, and Ae/Ap ratio
C
Loop for new
Ae/Ap
GRAPHS
Ae/Ap that produces
worst-release hazard
distance for user
specified meteorology
D
ERCB_SLAB.dll
Loop for new
Ae/Ap
1
Loop for new
windspeed and
stability
TOX output
ERCBSLAB output
GRAPHS
Ae/Ap that produces worst-release
hazard distance
Worst-release hazard distances
for 54 meteorological conditions
Dispersion Condition Probability
weighted hazard distances
E
ESD Closure
For an Ae/Ap ratio, the rate of release is used to determine how fast the
automated emergency shut down (ESD) valves can respond to the release rate.
The ESD valves can respond in three ways: by the responding to a drop in
pressure from the current operating pressure (ESD Valve Low Pressure Setting,
Pesd, on the INPUTS page); on the rate of change of pressure (ESD Valve Pressure
rate of change, dP/dt, on the INPUTS page); or by manual closure time (on the
INPUTS page). The pressure changes at the valve are used to determine which
of the two automation controls will trigger the valve closure first and then
4 Program Operation
49
compared to the manual valve closure time. This timing plus the time it takes to
the ESD to close, is used to calculate the amount of gas that passes through the
valve from the time of the release to the closing of the valve. The total release
volume is the calculated standing volume between ESD valves plus the above
estimated extra volume that flows by the valves before they close.
command.
This calculation is started using the ERCBH2S→ESD Closure
Results are displayed on the ESD CLOSURE page for the selected hole size
ratios.
The user can vary the parameters such as distance between ESD valves, pipe
sizes, ESD closure settings, or hole size, to investigate the effects these
parameters have on the calculated ESD Closure timing. For large holes, the
results demonstrate that either pressure ratio or the pressure rate of change can
trigger the closing of the valve depending on the site-specific parameters entered.
Pressure rate of change settings can have a strong influence on reducing release
volumes. For small holes, the ESD Closure calculations indicate that that neither
the pressure ratio nor the pressure rate of change settings may trigger the closing
of the valve, rather manual closure is required.
The ESD CLOSURE page is described in more detail on page 100.
Ae/Ap Ratio Search
For the PIPELINE flavour scenario, a release and the calculated downwind
concentrations are a function of the hole size, which is expressed as the exit area
to pipeline cross-section area ratio (Ae/Ap). To assist in the search for the worst
case exit area ratio, the ERCBH2S program has been automated to repeat the
overall calculation process for a range of hole size ratios. This iteration process is
command and
started using the ERCBH2S→Ae/Ap Ratio Search
intermediate calculations are displayed on the AeAp-Iteration page where the
selected hole size ratios are listed. This calculation process calls on the ESD
Closure routine to determine the ESD closure timing which determines the
release rate and duration for each of 11 hole sizes.
The exit area ratio iteration is initialized by completing the Basic Calculation
sequence, Ae/Ap Ratio Search. A Worst-Release Hazard Distance is
estimated based on the iteration for exit area ratio using the single meteorological
stability class and wind speed entered on the INPUTS page. The results are listed
on the HAZARD DISTANCES page. Intermediate results are displayed on the
AeAp-Iteration that also displays a tabular matrix of results and also a
graphical representation. These results were calculated for a selected
meteorological wind speed and stability class entered in the INPUTS page. The
user can vary the parameters such as distance between ESD valves, pipe sizes,
4 Program Operation
50
ESD closure settings, hole size or meteorological parameters, to investigate the
effects these parameters have on the calculated ERP zones.
The exit area ratio iteration is relatively quick but may take
several moments to complete the various calculations. It is
recommended that you do not use your computer for other
purposes during the calculations.
If a user-specific Ae/Ap Ratio is entered on the INPUTS
page, the CALCULATE EPZ calculation is performed for
all meteorological cases for the user-specific Ae/Ap Ratio,
thus by-passing the Ae/Ap search. Red flag are
displayed to warn the user that results displayed do not
represent the complete EPZ calculation process. The userspecific Ae/Ap Ratio field must be cleared in order to
complete the EPZ calculation process.
The AeAp-ITERATION page is described in more detail on page 100.
Calculate EPZ
The ERP zones are determined for the WELL, PIPELINE and LIQUID flavours,
by iterating to determine the meteorological stability class, wind speed and exit
area ratio (for PIPELINE flavour) that is associated with the Dispersion
Condition Probability Weighted Hazard Distances. The iteration process is started
using the ERCBH2S→Calculate EPZ
command.
The iteration process is repeated 54-times for the various combinations of
meteorological stability and wind speeds. For the PIPELINE flavour, the ESD
Closure timing and Ae/Ap Ratio Search calculations are also performed for
11 release area fractions.
The iteration for calculating Worst-Release Hazard
Distance is relatively quick but may take several
moments to complete the numerous calculations. It is
recommended that you do not use your computer for
other purposes during the calculations.
If a user-specific Ae/Ap Ratio is entered on the
INPUTS page, the CALCULATE EPZ calculation is
performed for all meteorological cases for the userspecific Ae/Ap Ratio, thus by-passing the
Ae/Ap Search. Red flags are displayed to warn
the user that results displayed do not represent the
complete EPZ calculation process. The user-specific
Ae/Ap Ratio field must be cleared in order to complete
the EPZ calculation process.
4 Program Operation
51
The run progress is shown at the bottom of the Excel
page. You may stop the Screening Matrix calculations
at any time by clicking the Space Bar or the ESC
key.
The results are listed in sections METMATRIX (page 97), GRAPH-MET (page
110), HAZARDS (page 107), and HAZARD DISTANCE (page 99).
.
4 Program Operation
52
5.
INPUTS Page
Input pages have a green sheet tab (note that some versions of Windows do not
display the page/sheet tabs in colour). In this section, the INPUTS page is
described in detail. The BATCH page is described on page (117). There are
many parameters required by ERCBH2S and these have been divided into the
following logical sections:
SECTION
ENTRY
DESCRIPTION
Administrative
Mandatory
Information about the applicant, the location under
study, the scenario name, and selection of the
Flavour for the template and analysis type.
Gas Pipeline
Mandatory
If the Flavour is GAS PIPELINE, physical
characteristics of the pipeline are specified.
Gas Well
Mandatory
If the Flavour is GAS WELL, physical
characteristics of the well are specified.
Liquid Pipeline
or Liquid Well
Mandatory
Sour Gas Composition
Mandatory
Advanced User Selected
Case
Optional – user
entries in this
section are not
acceptable for
ERCB submission
If the Flavour is LIQUID PIPELINE/WELL,
physical characteristics of the liquid release are
specified.
A representative chemical composition of the gas
phase in the pipeline or well is specified (dry).
For Advanced Users Only
This section allows the user to control calculations
for selected meteorological conditions and
pipeline release hole size rather than running the
complete screening matrix.
The WITH MITIGATION analysis may be helpful to
determine ignition commitments or advanced technology to
mitigate the hazard.
The input cells have conditional formatting that can be overwritten when cells are copied from one location to another.
If the INPUTS page does not look quite right, open the
blank ERCBH2S-Inputs.xls and re-enter the data.
5 Inputs Page
53
Entering Data
User specific data is entered in the ERCBH2S program following steps below:
1.
Select Launch ERCBH2S.xla. Then open an ERCBH2S-Inputs.xls
file or a ERCBH2S example file, such as ERCBH2S-Pipeline.xls or
ERCBH2S-Well.xls. These files can be found using Windows Explorer
and navigating to the installation directory for the ERCBH2S program.
Alternatively, links to these file have been included under the Windows
desktop START menu, under the ERCBH2S program.
2.
Navigate to the INPUTS page by clicking the “INPUTS” tab for the
worksheet.
3.
The cells and pages are presented in colours to assist in the data entry
process. Note that earlier versions of Excel do not display the page/sheet
tabs in colour.
LEGEND
cells
Prompt description or comment
cells
Entry prompt
cells
Protected or locked calculation
cells
Warning regarding a prompt or calculation that requires special attention
cells
Default value, Locked
cells
Protected or locked calculation output
sheet tabs Inputs
sheet tabs Summary/Graphics
sheet tabs Calculations
sheet tabs User Information
5 Inputs Page
54
Erasing the Inputs Page
The INPUTS page can be completely cleared by selecting ‘Erase all inputs
fields’ from the Technical sub-menu as shown below. This command does not
erase inputs on the BATCH page.
Red Flags and other Warnings
Red Flag Warnings
A red flag warning appears as a banner at the top of many ERCBH2S Excel
pages when user inputs are missing, outside of allowable ranges, or have changed
since the last calculation sequence was performed. It is important to
remember that at any one time, there is only one current set of calculation results
displayed on the ERCBH2S Excel pages (other than the BATCH page, which can
store many different sets of calculation result records).
A BATCH page export file, without red flags or other
error messages, is required for a licensee/applicant’
submission to the ERCB.
5 Inputs Page
55
Missing Entry
There are two types of missing input data flags. Missing entries for ERCB
Submission do not effect the calculation but are required for completeness:
**(1) Missing entry(s) for ERCB Submission**
Missing entries for calculations will effect the calculation. Notice that as a result,
inputs to several other programs have changed so the displayed outputs do not
match the inputs.
Out of Bounds Entry
Out of bounds entries must be corrected before submission. The program will
calculate the ERP zones based on the model inputs (either on user inputs or model
‘orange re-sets’ – described later in this section), but the error flag will continue.
**(1) Out of bounds entry(s)**
Recalculation Required
Calculations in the ERCBH2S program can be computationally intensive,
requiring several minutes to complete. Rather than recalculate output for every
change of input or immediately erasing all output when input information
changes, ERCBH2S displays the following:
ERCBH2S describes the individual program components that must be re-run
based on the changed inputs. Selecting ‘Calculate EPZ’ automatically runs the
necessary programs, and these descriptions in the red flag will be removed (if
there are no other errors encountered).
If the flavour selected is a pipeline and the User Selected Case (bottom of the
INPUTS page) includes an entry for the Gas Pipeline Release Hole Size
Fraction, the following flag will appear if you just ran Calculate EPZ:
INPUTS DO NOT MATCH DISPLAYED OUTPUT PAGES -- RECALCULATIONS REQUIRED: ,AeAp Calculation
5 Inputs Page
56
Delete the Gas Pipeline Release Hole Size Fraction and Run
Calculate EPZ to remove the flag. User ‘over-rides’ of default entries in ‘User
Selected Case’ on the INPUTS page always create a red flag and are therefore
not suitable for ERCB submission. Work in this section of the INPUTS page is
reserved for the advanced technical user to investigate intermediate calculations
and mitigation strategies for a selected meteorological and/or Gas Pipeline
Release Hole Size (Fraction).
A red flag can also be displayed if the user has not selected a flavour for the
current scenario; either, GAS PIPELINE, GAS WELL or LIQUID
PIPELINE/WELL. Calculations cannot proceed without selecting a flavour.
To remove red flags that contain calculation messages, the CALCULATE
EPZ command must be run. This command runs all the calculations for the GAS
PIPELINE, GAS WELL or LIQUID PIPELINE/WELL flavours for all
screening meteorological cases, and will end by running the individual
meteorological case specified on the INPUTS page.
To remove red flags with calculations messages, the
CALCULATE EPZ command must be run.
If default settings in User Selected Case have been
changed, a red flag will occur. These calculation results
are not acceptable for ERCB submission.
Orange Warnings
Notice the right hand column (column E) on the ERCBH2S INPUTS page. The
heading for this column (as shown in the next section on ‘Administrative’) is:
Warnings
(if applicable)
Try deleting a few of the Administrative entries. Note that entries with the
warning Required for ERCB submission
are required for ERCB submission but are
not required for the calculation to proceed.
Entries with the warning Required for calculation
are required for
ERCBH2S calculations to proceed and must be entered. Note that all fields accept
text input and have a general format.
5 Inputs Page
57
Orange Warnings will cause a red flag error message. If not addressed by the
user, this flag will be attached to the calculation results. Calculation results with a
red flag error message are not acceptable for ERCB submission.
The user must verify that the data is entered in accordance
with the units specified beside each data entry location.
If not addressed by the User, Orange Warnings cause a
red flag error message which will persist through to the
calculation results. Calculation results with a red flag
error message attached to them are not acceptable for
ERCB submission.
The ERCBH2S-INPUTS.xls template worksheets are
security protected to prevent accidental overwriting of the
intermediate calculations or general formatting. Although
the formulae in the worksheets cannot be changed, the
formulae can be viewed by selecting the worksheet cell and
tracing the logic.
Orange Resets
Many user inputs have an ERCB prescribed value range – a minimum and
maximum value that can be entered. The allowable range for each row (where
applicable) is shown to the right of the INPUTS page in columns H and I.
Column J describes the ‘model action’ associated with user inputs that are outside
of the acceptable range. Observe that some model actions are listed as ‘resets’.
These are referred to as ‘orange resets’.
For rows with orange reset actions, if the user entry is below the minimum limit,
the model resets the entry to the lowest allowable value. If the entry is above the
maximum limit, the model resets the entry to the highest allowable value. For
model ‘resets’, it is important to remember that the user entry (in column C) is not
changed - instead the reset value appears in column E and is coloured orange to
warn the user that one of their entries has been reset.
If orange reset entries appear on the INPUTS page, ERCBH2S
calculations will be based on these values (for the applicable field), and
NOT the user entry. To remove the orange reset warning from column E
(and subsequently a red flag error message attached to the calculation
results); the user must change their entry to be within the allowable limits
BEFORE activating any ERCBH2S program run commands.
5 Inputs Page
58
When ERCBH2S resets a user entry, the ‘reset’ model entry
(shown in column E on the INPUTS page) appears in
orange, and planning zone calculations will be performed
using the orange reset entry. To remove the orange reset
warning, the user must change their entry (column C) to be
within allowable limits. If this is not done, there will be a
red flag error message attached to the calculation results,
and the results are not acceptable for ERCB submission.
Green Notifications
Green notifications that appear in column E on the INPUTS page are for user
information purposes only. A red flag error message is not generated.
An example of this notification can be found next to Datum for Surface
Optional
Locations:
. The entry field is included to assist
the user in data record management, but relates to location inputs in each details
group.
Administrative
In the Administrative input section, shown below, input is required to identify the
licensee, contact information, scenario name, sour operation type, analysis type,
and certain operation location descriptions/identifiers.
5 Inputs Page
59
5 Inputs Page
60
The following table describes the data required in the Administrative input
section.
Field
Description
BA Code
Licensee/Applicant
Mailing Address
City and Province
Postal Code
Contact
Name
Phone
Fax
E-mail
Business Associate code assigned by ERCB.
The name of the licensee or prospective licensee.
The complete address to be used for mail correspondence relating
to the submission.
The name of the individual responsible for submitting the evaluation.
This person may be contacted for additional information or
supporting assessments regarding the submission.
Each analysis must be given a unique identifying scenario name.
This is especially important for operating the ERCBH2S program in
Batch mode, where the Scenario Name is used as the identifier
for the record in the database.
Scenario Name
If using the ERCBH2S ‘Gathering System Analysis’ feature on the
BATCH page (Chapter 9 - Pipeline Gathering Systems), refer to
the suggested scenario naming format in Chapter 9 under Pipeline
Segment Label (Scenario Name).
See Page Label 3.
Sour Operation Type
This selection determines which one of three modelling methods the
user will activate. Depending upon the choice made, two of the
three sour operations details groups (further down the INPUTS
page) will be ‘greyed out’. See Sour Operation Type later in this
chapter for further details.
This selection turns off/on access to SOURCE MITIGATION
entries in the applicable sour operations details group (shown
further down on the INPUTS page). While access to SOURCE
Analysis Type
Name of Well or Pipeline
Licence Number
MITIGATION allows a user to deviate from ERCB default source
mitigation values, justification, proof and/or a demonstration of the
licensee/applicant’s ability to conduct/apply the mitigative control
within the specified time-frame (for each deviation) may be
requested by the ERCB. See Analysis Type later in this chapter
for further details.
As per the licence or application. For new pipeline applications
without a licence number, enter “na”.
See Page Label 1.
5 Inputs Page
61
Field
Well Licence Number or
Application Number
Description
As per the well licence or application. For a pipeline or new well,
enter “na”.
The well’s surface location or the pipeline line number.
Legal Surface Location of
Well or Pipeline Line
Number
If modelling a portion of a pipeline line number, attach an
alphabetical character to the line number - describing the subsegment being modelled and the extent of sub-segments possible.
For example, if modelling the second ‘sub-segment’ of line number
17 and the line is modelled in five sub-segments, enter ‘Line 17b
of e’.
See Page Label 2.
Pipeline From Location
As per the pipeline licence or application. If modelling a portion of a
pipeline line number, enter the LSD/SEC/TWP/RGE/MER location
of the upstream/start of the pipeline sub-segment. If modelling a
well, enter “na”.
Pipeline To Location
As per the pipeline licence or application. If modelling a portion of a
pipeline line number, enter the LSD/SEC/TWP/RGE/MER location
of the downstream/end of the pipeline sub-segment. If modelling a
well, enter “na”.
Surface Elevation
The average EPZ elevation (metres above sea level, as determined
from topographical maps) is used to determine the average
atmospheric pressure and is important to accurately convert mass
emissions of H2S into volume concentrations of parts per million
(ppm). If this cell is left blank, a value of zero (for sea level) is used
by ERCBH2S.
For a well, enter the well’s surface elevation. For a pipeline, enter
the pipeline’s average elevation (+/- 100 m).
Existing EPZ Distance
For the implementation phase of ERCBH2S, the existing EPZ
distance for a facility, in kilometres, is required for comparison. For
new facilities, enter “na”.
5 Inputs Page
62
Field
Description
To accommodate the various mapping standards that may be
applied by users, each application can specify the datum and
projection adopted for the entry of mapped locations. The datum
and project may be one of:
Datum for surface locations
•
UTM NAD27 zone 11
•
UTM NAD27 zone 12
•
UTM NAD83 zone 11
•
UTM NAD83 zone 12
•
10TM NAD83
•
WGS84 (latitude/longitude)
• Other
This optional entry allows ERCBH2S to integrate with GIS systems
used for ERP and mapping. If “Other” is specified
•
the user may elect not to enter mapping coordinates in the
facility details group (further down on the INPUTS page),
or
•
the applicant may choose to enter mapping coordinates in
the facility details group (further down on the INPUTS
page), however, the application should* clearly indicate the
mapping datum and projection referenced (*if the user
wishes to integrate with a graphics package).
ERCBH2S Page Labels
Each ERCBH2S page has a label attached to it so you can track the pages. The
label is derived from certain user inputs in the Administrative group on the
INPUTS page, described below.
For a well, the label is created using:
Well name (Label 1)/Legal surface location (Label 2)/Scenario name (Label 3)
For a pipeline, the label is created using:
Pipeline licence No. (Label 1)/Line number (Label 2)/Scenario name (Label 3)
Sour Operation Type
There are three sour operations types (analysis flavours): GAS PIPELINE,
GAS WELL and LIQUID PIPELINE/WELL. One of the three flavours must
be selected in order for calculations to proceed.
5 Inputs Page
63
SOUR OPERATION
TYPE
DESCRIPTION
Determined by the pipeline substance category as defined by
ERCB Directive 056, with the exception of the substance ‘Acid
Gas’. Acid Gas is defined as
Gas that is separated in the treating of solution or nonassociated gas that contains hydrogen sulphide (H2S),
totally reduced sulphur compounds, and/or carbon
dioxide (CO2).
For ERCBH2S, the ERCB requires that pipelines containing
Acid Gas be identified separately from other Sour Gas
pipelines, even though they are licensed as ‘Sour Gas’
pipelines. ‘Gas Pipeline’ modelling is also required for Oil
Effluent pipelines with:
•
GAS PIPELINE
(transient jet)
a Gas to Liquid Ratio (GLR) > 1000 (at stock-tank
conditions of 15º C and 101.325 kPa), and
•
an H2S concentration ≥0.01 % (mole percent,
equivalent to 0.1 mol/kmol or 0.0001 mole fraction or
100 ppm) in the gas phase (dry).
Gas pipeline releases are characterized by a high pressure
transient jet (a non-steady release rate). Pipeline releases are
assumed to occur at the midpoint of the pipeline segment.
Special notice concerning HVP pipelines that contain H2S;
- these pipelines must be modelled in ERCBH2S to compare
the size of the resulting EPZ with that derived from an HVP
model (see Directive 071). Because HVP is NOT one of the
pipeline substances listed on the ERCBH2S INPUTS page,
the user must select the “LVP Products Pipeline with GLR ≤
1000” from the Sour Operation Type drop-down list. Be aware
that the gas being modelled must be from stock-tank conditions
of 15°C and 101.325 kPa (dry analysis).
Primarily used for gas wells containing sour gas (hydrogen
sulphide, H2S), ‘Gas Well’ modelling is also required for wells
of any substance (including liquids) with:
•
GAS WELL
(steady jet)
5 Inputs Page
a Gas to Liquid Ratio (GLR) > 1000 (at stock-tank
conditions of 15º C and 101.325 kPa), and
•
an H2S concentration ≥0.01 % (mole percent,
equivalent to 0.1 mol/kmol or 0.0001 mole fraction or
100 ppm) in the gas phase (dry).
Gas well releases are characterized by a steady flow rate jet at
the specified rate. Gas well releases of sour gas are not
permitted to discharge continuously and may be required to be
ignited.
64
SOUR OPERATION
TYPE
DESCRIPTION
Primarily used for oil and produced water, ‘Liquid Pipeline or
Liquid Well’ modelling is required for any fluid with:
•
LIQUID PIPELINE
or LIQUID WELL
(steady jetl)
a Gas to Liquid Ratio (GLR) ≤ 1000 (at stock-tank
conditions of 15º C and 101.325 kPa), and
•
an H2S concentration ≥0.01 % (mole percent,
equivalent to 0.1 mol/kmol or 0.0001 mole fraction or
100 ppm) in the gas phase (dry).
Liquid releases are characterized by a steady flow jet of gas
and a pool of liquid on the ground. The release leads to the
immediate volatile liberation of sour solution gas.
If modelling a drilling well with potential to encounter both gas and liquid H2S
bearing formations (e.g. one zone is gas while another is liquid), the user must
model the Cumulative H2S Release Rate using only the Gas Well portion of the
INPUTS page.
Analysis Type
(Source Mitigation… it’s all about time)
NO MITIGATION
1
WITH MITIGATION
The Analysis Type, either, NO MITIGATION or WITH MITIGATION,
effectively turns off or on user access to the subsection called
SOURCE MITIGATION contained within each of the three details groups GAS WELL, GAS PIPELINE, and LIQUID PIPELINE or LIQUID WELL.
For a NO MITIGATION analysis, user inputs are set to ERCBH2S DEFAULT
values and cannot be changed. The SOURCE MITIGATION descriptions and
values appear greyed-out, and the values listed under the Model Input heading
(column E) are used. Any user inputs are formatted to appear invisible because
the model does not use them. After completing a NO MITIGATION analysis,
the user may choose to assess the site-specific source mitigation inputs in more
detail.
NO MITIGATION
2
WITH MITIGATION
When the user selects a WITH MITIGATION analysis type, the
SOURCE MITIGATION subsection is ‘opened up’ (appears non-grey) and the
5 Inputs Page
65
input parameters are unlocked. The user may now deviate from the recommended
ERCBH2S DEFAULT values in the WITH MITIGATION, provided the user
input is within allowable limits.
SOURCE MITIGATION - General
Allowable Limits
The lower (minimum), upper (maximum) and ‘Model Action’ for each
SOURCE MITIGATION row is shown to the immediate right on the INPUTS
page, in columns H, I and J. Observe that the ‘Model Action’ is always ‘Resets’.
This means that if the user enters a value outside of the allowable limits, the
model automatically ‘resets’ the user entry, and the reset entry is displayed in
column E under MODEL INPUT. The resulting ‘orange reset’ creates a
red flag error message. For more details on managing an ‘orange reset’, see
Orange Resets in this chapter. There is a detailed discussion of the source
mitigation options for each of the details groups within each section (Gas
Pipeline, Gas Well, and Liquid Pipeline or Liquid Well).
Licensee/Applicant Responsibility
When changing ERCB default entries in the SOURCE MITIGATION
subsection of any of the details groups, the licensee/applicant is required to
document and be prepared to defend the model input values, as they must do with
any of the other model inputs.
A WITH MITIGATION analysis may result in smaller calculated ERP zones
because the source duration is reduced. As source mitigation improves, the size
of the hazard decreases. Note that while some planning zones sizes decrease with
changes to the source mitigation time, significant EPZ changes are not realized
until mitigation time is reduced to 3 hours (180 minutes) or less.
The user should provide documented justification in the
Audit Package for each entry in a WITH MITIGATION
analysis that deviates from the ERCB default value.
Note that while some planning zones sizes decrease with
changes to the source mitigation time, significant EPZ
changes are not realized until mitigation time is reduced
to 3 hours (180 minutes) or less.
For ERCB submission, applicants are required to activate
the program run command ‘Calculate EPZ’, and submit
either the NO MITIGATION or the
WITH MITIGATION analysis – depending on mitigation
controls available to the operation being modelled.
5 Inputs Page
66
Remember that source mitigation requires
commitments to earlier ignition, shut in of flow,
specified emergency shutdown valve closure or other preplanned actions that stop the release of H2S.
Gas Pipeline
The Gas Pipeline details group is also designed for Oil Effluent pipelines with a
Gas to Liquid Ratio (GLR) > 1000 as measured at stock-tank conditions of 15º C
and 101.325 kPa (dry gas analysis). Gassy Oil Effluent pipelines are included in
this group because they will have a transient blow-down.
The Gas Pipeline details group has two sections. The first section is open to any
user whose initial selection (in SOUR OPERATIONS TYPE) brought them to
this group. The second ‘sub-section’, titled SOURCE MITIGATION, is only
open to those users who selected the analysis type WITH MITIGATION. When
the NO MITIGATON analysis is selected, the source mitigation inputs are
disabled as shown below. General details on allowable entry limits, and
licensee/applicant responsibility for changing default entries in SOURCE
MITIGATION can be found under Source Mitigation - General in this chapter.
Details specific to the Source Mitigation subsection for the Gas Pipeline group are
described later in this section.
5 Inputs Page
67
Notice the Comments column (column D) to the right of the user input column
(column C). It contains additional information on some of the cell requirements.
Field
Description
Pipeline Segment From
Location Coordinates
The ‘beginning/upstream’ pipeline segment (or sub-segment)
coordinates according to the mapping datum and projection
selected in the Administrative inputs section. These entries
are optional and may be left blank.
Pipeline Segment To
Location Coordinates
The ending/downstream’ pipeline segment (or sub-segment)
coordinates according to the mapping datum and projection
selected in the Administrative inputs section. These entries
are optional and may be left blank.
Licenced Maximum
Operating Pressure
Expected Maximum
Operating Pressure
The maximum operating pressure (MOP) for which the
pipeline is licensed, kPa (gauge).
The highest operating pressure expected – under any
circumstances, kPa (gauge). This pressure must not be
exceeded without first recalculating the emergency planning
zones and proceeding with an ERP modification/update in
accordance with ERCB Directive 071 requirements
Emergency planning zone calculations are referenced from
the Expected Maximum Operating Pressure. This pressure
can be lower than the licenced maximum operating pressure,
but under no circumstances can it be higher.
Pipeline Outside Diameter
Pipeline Wall Thickness
The diameter of the pipe outside diameter, mm
The wall thickness of the pipe, mm
The length of pipeline segment being modelled (entered in
metres). It must be one continuous piece of pipe with
consistent characteristics such as describe a pipeline licence
line number – governed by ERCB Directive 056.
Segment Length
5 Inputs Page
Smaller ‘sub-segments’ can be modelled as defined by ‘node’
locations (see Gas Gathering System Analysis - Tutorial in
Chapter 9). Nodes are defined as changes in operating
conditions, physical pipe changes, substance changes, tie-ins,
ESD valves and check valves.
68
Field
Description
The equivalent length of pipeline between emergency shut
down valves (entered in metres), as determined by the
pipeline gathering system network analysis, or by manual
calculation. See Chapter 9 - Pipeline Gathering Systems
(which also describes the manual calculation).
*Equivalent Segment Length
between ESDs
(enter Length or Volume below)
The Equivalent Segment Length can be the same as the
Segment Length (above) IF, when all flow control valves are in
a closed position, there is no additional pipeline substance
material that can flow into the subject pipeline segment.
Under no circumstances can the Equivalent Segment Length
be less than the Segment Length.
The user must enter either this Equivalent Segment Length
OR the Equivalent Cumulative Pipeline Volume (next row
down on the INPUTS page). Do not enter both values.
When one value is entered, the other row is greyed-out.
Emergency planning zone calculations are referenced from
the Equivalent Segment Length.
The equivalent cumulative pipeline volume between
emergency shut down valves, as determined by the formula
described in the pipeline gathering system network analysis
(entered as m3). See Equivalent Cumulative Pipeline Volume
(between ESDs in Chapter 9).
*Equivalent Cumulative Pipeline
Volume between ESDs
(enter Volume, or Length above)
The user must enter either this Equivalent Cumulative
Pipeline Volume OR the Equivalent Segment Length (previous
row on the INPUTS page). Do not enter both values. When
one value is entered, the other row is greyed-out.
Emergency planning zone calculations are referenced from
the Equivalent Segment Length calculated from the equivalent
cumulative pipeline volume.
*Next to ‘Equivalent Segment Length between ESDs’ and ‘Equivalent Cumulative Pipeline Volume’,
observe that the ‘comment’ cell in column D on the INPUTS page is ‘active’. When one of the two
entries is provided by the user, ERCBH2S calculates the ‘missing’ user entry and displays the
result in column D. If the user entered the Equivalent Segment Length, column D immediately
displays the calculated volume (next to the Equivalent Cumulative Pipeline Volume). If the user
entered the Cumulative Pipeline Volume, column D immediately displays the calculated length
(next to the Equivalent Segment Length between ESDs).
Expected Maximum
Gas to Liquid Ratio
5 Inputs Page
The modelled solution gas to liquid ratio (m3/m3) as measured
at stock tank conditions of 15º C and 101.325 kPa (dry gas).
This row is only applicable to Oil Effluent pipelines. In the
Sour Operations Type (Administrative section of INPUTS
page), if the user selected a pipeline substance of Sour Gas,
Natural Gas or Acid Gas, this row is greyed-out.
69
Field
Description
The maximum H2S concentration of the pipeline licence
(entered in percent (%). The maximum H2S concentration
does not have to match the reference composition provided in
the gas composition (lower portion of INPUTS page).
Licensed Maximum H2S
Concentration
Pipelines directed to this category with an H2S below 0.01 %
(mole percent, equivalent to 0.1 mol/kmol or 0.0001 mole
fraction or 100 ppm) do not have to be modelled (ERCB
Directive 071). If they are modelled, the results do not need to
be submitted to the ERCB.
The highest H2S expected – under any circumstances,
entered in percent (%). This H2S must not be exceeded
without first recalculating the emergency planning zones and
proceeding with an ERP modification/update in accordance
with ERCB Directive 071 requirements.
This H2S can be lower than the licensed maximum H2S, but
under no circumstances can it be higher.
Expected Maximum H2S
Concentration
If the H2S entry is lower than the licensed maximum, it must
not be exceeded during pipeline operations. The H2S entered
must accommodate all production scenarios – with
consideration given to scenarios where only the highest H2S
well is producing through the pipeline if other wells are shut-in.
The Expected Maximum H2S Concentration does not have to
match the reference composition provided in the gas
composition (lower portion of INPUTS page).
Note that emergency planning zone calculations are
referenced from the Expected Maximum H2S Concentration,
and not the Licensed Maximum.
Pipelines with an Expected Maximum H2S below 0.01 % (mole
percent, equivalent to 0.1 mol/kmol or 0.0001 mole fraction or
100 ppm) do not have to be modelled (ERCB Directive 071).
If they are modelled, the results do not need to be submitted
to the ERCB.
5 Inputs Page
70
Field
Description
The pipeline operating temperature in degrees Celsius (ºC).
Although some pipelines may be heated to avoid hydrate
formation, it is the normal minimum temperature in a pipeline
segment that should be entered.
Minimum Gas Pipeline
Temperature
(ºC)
If the user entry cell is left blank a default value of 5°C (ground
temperature), is used. The allowable temperature range is
shown to the right of the INPUTS page, in columns H and I.
Observe that in column J, the ‘model action’ for this row is
‘resets’. This means that if a user entry is outside the
allowable range, an ‘orange reset’ will be applied. To
understand more about orange resets (and why a user must
change their entry to remove them) see Orange Resets in this
chapter.
Notice that the comment in cells M38 and M39 are ‘active’. They provide the
H2S release volume (m3) based on the User Inputs of pressure (kPa), equivalent
pipeline length (m), pipeline inside diameter (mm), H2S Concentration (licenced
and normal, %) and temperature (°C). The licenced release volume in Cell M38
uses atmospheric pressure of 101.325 kPa and the licenced maximum operating
pressure to determine the absolute pressure, the model input temperature and the
equivalent segment length. It is used for the pipeline release volume calculation
and Level Designation. The actual release volume in Cell M39 uses the
calculated atmospheric pressure which is less than 101.325 kPa and the expected
maximum operating pressure to determine the absolute pressure, the model input
temperature and the equivalent segment length. The display may note that the
volumes are for an ideal gas. To determine the real gas values run
ERCBH2S→Technical→Run ERCBFlash Only....
Gas Pipeline Group- Source Mitigation Sub-section
If the WITH MITIGATION analysis was selected in the Administrative section
of the INPUTS page, several more parameters are available for entry to manage
pipeline emergency response planning. The WITH MITIGATION analysis
entries (see below) include mitigation controls for emergency shutdown (ESD)
valves on the pipeline. ERCBH2S accounts for five ESD valve mitigation
measures: the time it takes the valve to close once it has been activated to close;
the low pressure setting that will trigger the valve to close, the Pressure Rate of
Change (PROC) that will trigger the valve to close (including an instrument
sampling time to determine the pressure rate of change), the time to manually
trigger valve closure; and the time to ignite/draw-down or otherwise terminate the
release.
5 Inputs Page
71
For additional information on a licensee/applicant’s responsibility when changing
default entries in the SOURCE MITIGATION section, see Source Mitigation Licensee/Applicant Responsibility in this chapter.
When to Change the Default Settings
The ERCB default settings in this group result in no effective ESD control for a
pipeline release.
A user should only change the valve settings (over-ride the default settings) IF the
material flow of the pipeline segment being modelled is completely controlled
by ESD valves, or a combination of ESD and back-flow check valves. This
includes other pipelines tying into the modelled segment (if these other
pipelines can contribute material to the subject pipeline segment in the event of a
release).
At each point where material can enter the subject pipeline – both upstream and
downstream – the user must follow the source(s) back until a flow control device
is located. The flow control device with the lowest setting is the setting that can
be modelled. If there is any instance where a flow control device cannot be
located, then the default settings in this group must not be changed. Note that for
modelling purposes, check valves are assumed to close immediately and
completely.
Pre-set ERCBH2S valve settings DO NOT PROVIDE
EFFECTIVE ESD CONTROL for a pipeline. The user must
adjust the setting if the material flow (both to and from the
pipeline segment) is COMPLETELY controlled by ESDs or a
combination of ESDs and back-flow check valves.
The ERCB default settings in this group result in no effective
ESD control for a pipeline release
When modelling a pipeline segment with multiple valve
settings (as happens in some gathering systems), the lowest
valve setting must be used.
Note that while some planning zones sizes decrease with
changes to the source mitigation time, significant EPZ
changes are not realized until mitigation time is reduced
to 3 hours (180 minutes) or less.
The model assumes infinite flow from both upstream and
downstream of a pipeline. If the ESD valve does not have a
LP trigger setting, then the default of 10 % of the expected
maximum operating pressure is used.
A low pressure trigger of 10 % means that the pipeline has to
depressure to of its total operating MOP before the ESDs will
close. This means the associated EPZ will be very large,
5 Inputs Page
72
almost equal to a case suing no mitigation.
If the user has an ESD valve, the recommended LP trigger
setting is at least 50 % of the expected maximum operating
pressure.
A low pressure trigger of 90 % is generally unreasonable, as
daily fluctuations in pipeline pressure would cause the ESDs
to close.
Field
ESD Valve Closure Time
once Triggered
(s)
Description
The closure time is the time it takes the ESD valve to close
once it has been activated to close, either by low pressure
setting or pressure rate of change, (seconds). If the cell is left
blank then the large default value of 60 s is used.
The normal low pressure (LP) setting is entered as kPa
(gauge).
If the ESD valve does not have a LP trigger setting, then the
cell is left blank and the default of 10 % of the expected
maximum operating pressure is used.
ESD Valve Low Pressure
Trigger, Pesd
(kPa gauge)
If the user has an ESD valve, the recommended LP trigger
setting is at least 50 % of the expected maximum operating
pressure.
Note that the ERCB may field verify valve settings. The
percent that was modelled (ratio of Valve Setting to Expected
Maximum Operating Pressure) will be applied to the actual
operating pressure. Licensee must ensure their pipeline is not
operating with valve settings (percent/ratio) any lower than
what was modelled.
ESD Valve Pressure Rate of Change
(PROC) Trigger, dP/dt
(kPa/s)
5 Inputs Page
The pressure rate of change (PROC) trigger setting is used to
control the closure of the ESD valve based upon how quickly
the pressure is changing at the ESD. PROC is entered in
units of kPa/s.
If the ESD valve does not have a PROC trigger setting, then
the cell must be left blank. The default pressure drop of the
normal operating pressure over 1 second will be used – which
effectively cancels any potential mitigation advantage due to
PROC.
73
Field
Description
The pressure rate of change (PROC) is determined by the
valve instrumentation using a sampling time (seconds).
ESD Valve Pressure Rate of Change
(PROC) Sampling Time
(s)
If the ESD valve does not have a PROC trigger setting, then
the cell is left blank and a large default is used (3600 s) –
which effectively cancels any potential mitigation advantage
due to PROC.
The time it takes from the moment the release occurs to
manually (or remotely) close the valve (minutes). The total
time entered must provide time to
Time from initial release until
ESDs manually or remotely closed
(minutes)
•
detect the release (usually through odour complaint),
•
contact the operator,
•
travel to the site,
•
verify a release is occurring, and
• trigger valve closure.
Unless the licensee can perform the above actions, for all
related valves (that ensure complete pipeline isolation) in less
than 720 minutes (12 hours), this field should be left blank.
The time it takes from the moment the release occurs to
igniting the release, plugging the hole or a drawdown of the
pressure (minutes). Effectively the H2S release is completely
stopped. The total time entered must provide time to
Time from initial release
until ignition or stop flow
(minutes)
•
detect the release (usually through odour complaint),
•
contact the operator,
•
travel to the site,
•
verify a release is occurring, and
•
perform a prescribed, pre-planned action that prevents
additional H2S from being released, such as ignition.
Unless the licensee can perform the above actions in less than
720 minutes (12 hours), this field should be left blank.
Gas Pipeline Group - Orange Resets
The lower (minimum), upper (maximum) and Model Action for each
SOURCE MITIGATION row is shown to the immediate right on the INPUTS
page, in columns H, I and J. Observe that the ‘Model Action’ is always ‘Resets’.
This means that if the user enters a value outside of the allowable limits, the
model automatically ‘resets’ the user entry, and the reset entry is displayed in
column E under MODEL INPUT. The resulting ‘orange reset’ creates a
red flag error message which must be dealt with.
For details on why orange resets occur, why they must be managed and how, see
Orange Resets in this chapter.
5 Inputs Page
74
Gas Well
The Gas Well details group is also designed for liquid and other wells with a Gas
to Liquid Ratio (GLR) > 1000 as measured at stock-tank conditions of 15ºC and
101.325 kPa. These gassy wells are included in this group because they will have
a steady jet release.
The Gas Well details group has two sections. The first section is open to any user
whose initial selection (in SOUR OPERATIONS TYPE) brought them to this
group. The second ‘sub-section’, titled SOURCE MITIGATION, is only open
to those users who selected the analysis type WITH MITIGATION. When the
NO MITIGATON analysis is selected, the source mitigation inputs are disabled
as shown below. For general details on allowable entry limits and
licensee/applicant responsibility for changing default entries in SOURCE
MITIGATION, see Source Mitigation - General in this chapter. Details specific
to the Source Mitigation subsection for the Gas Well group are described later in
this section.
Notice the Comments column (column D) to the right of the user input column
(column C). It contains additional information on some of the cell requirements.
Field
Phase of Well Operations?
Is Well Classified as Critical?
Unique Well Identifier
5 Inputs Page
Description
Specify drilling, completion/servicing/workover or
producing/injection/suspended from the dropdown list.
Specify Yes or No using the buttons provided. This
classification is determined from the criteria in Guide 56–
Schedule 4
Specify the unique well identifier as per the well licence
or application.
75
Field
Well Centre
Surface Location Coordinates
Description
The well’s surface location coordinates according to the
mapping datum and projection selected in the
Administrative inputs section. These entries are optional
and may be left blank.
The inside diameter at the exit (in mm), of either the
casing or tubing.
Casing or Tubing Inside Diameter
at Exit
For Oil Effluent wells modelled as gas wells, the area
taken up by the diameter of the sucker rod (pumping
wells only) can be ignored; just use the tubing inside
diameter.
The highest H2S possible (appropriate to the phase of
well operation being modelled), entered in percent (%).
For new wells, this is the H2S provided in the well
licence application.
For existing wells, it is the highest possible H2S from
any formation capable of flowing to surface.
*Expected Maximum H2S
Concentration
The Hazard Modelling H2S Concentration does not have
to match the reference composition provided in the gas
composition (lower portion of INPUTS page). Note
that emergency planning zone calculations are
referenced from the Hazard Modelling H2S
Concentration.
Wells with an H2S below 0.01 % (mole percent,
equivalent to 0.1 mol/kmol or 0.0001 mole fraction or 100
ppm) do not have to be modelled (ERCB Directive 071).
If they are modelled, the results do not need to be
submitted to the ERCB.
5 Inputs Page
76
Field
Description
The volumetric H2S release rate at reference conditions
(m3/s at 15ºC and 101.325 kPa). While surface rates are
preferred (more representative), sand-face rates can be
entered (less representative, but more conservative
because they will be somewhat higher).
For new wells with an ERCB approved pre-submission
release rate, enter the pre-approved rate appropriate to
the phase of well operations being modelled.
*H2S Release Rate
(m3/s)
(Cumulative if Multi-zone)
For new wells without an ERCB approved presubmission release rate, enter the cumulative release
rate estimate provided in the well licence application –
appropriate to the phase of well operations being
modelled. If the well has potential to encounter both gas
and liquid H2S bearing formations (e.g. one zone is gas
while another is liquid), the user must model the
Cumulative H2S Release Rate using only the Gas Well
portion of the INPUTS page.
For existing (drilled) wells, enter a cumulative release
rate based on all formations capable of flowing to
surface.
If the well has a flow control device that restricts flow
AND the flow control device is inside the well’s tubing
(therefore not vulnerable to unexpected damage) AND
the user is modelling a ‘producing’ well scenario, the H2S
release rate may be based on the restricted flow rate at
surface. In this case, the flow control device only affects
the H2S release rate, not the well’s casing or tubing
inside diameter at exit.
Note - ERCBH2S is designed for calculating ERP zones,
not well release rates. Requirements/guidelines for
calculating well release are in other ERCB publications.
ERCBH2S-Gas Well does not recalculate the H2S release rate
when the casing or tubing diameter is changed. If you are
exploring different scenarios by changing the well diameter,
remember to adjust the H2S release rate accordingly.
Gas Well - Source Mitigation Sub-section
If the WITH MITIGATION analysis was selected in the Administrative section
of the INPUTS page, two more parameters are available for entry to manage
5 Inputs Page
77
‘well’ emergency response planning. The WITH MITIGATION analysis entries
(see below) include mitigation controls for Surface Controlled Sub-Surface Safety
Valves (SCSSSV) – a yes/no entry for producing wells only, and time from initial
release until ignition or stop flow (input value).
For additional information on a licensee/applicant’s responsibility when changing
a default entry in the SOURCE MITIGATION section, see Source Mitigation Licensee/Applicant Responsibility in this chapter.
When to Change the Default Settings
A user should only change the default settings (over-ride the default settings) in
this group IF the licensee can perform/coordinate the following actions within the
time frame indicated in this section of the model:
•
detect the release,
•
contact the operator (if the well operation is un-manned),
•
travel to the site (if the well operation is un-manned),
•
verify a release is occurring (if the well operation is un-manned), and
•
perform a prescribed, pre-planned action that prevents additional H2S from
being released (such as igniting the well or closing a valve).
Unless the licensee can perform the above actions in less than the time shown as a
default entry for this group, this field should be left blank. Note that the default
setting for ‘Time from initial release until ignition or stop flow’ changes with the
phase of well operation – which indicates if the site is manned or un-manned
(subsequently affecting the time to implement mitigation measures). In addition,
producing wells with a Surface- Controlled Sub-Surface Safety Valve (SCSSSV)
have a significantly reduced default setting.
Note that while some planning zones sizes decrease with
changes to the source mitigation time, significant EPZ
changes are not realized until mitigation time is reduced
to 3 hours (180 minutes) or less.
5 Inputs Page
78
The ERCB may request documentation that supports a
licensee’s non-default Time from Initial Release
until Ignition or Stop Flow values
Gas Well Group - Orange Resets
The lower (min.), upper (max.) allowable values for ‘Time from initial release
until ignition or stop flow’ change with the phase of well operation, and with the
presence of a SCSSSV. The allowable limits are shown to the immediate right on
the INPUTS page, in columns H and I. Observe that in column ‘J’ the ‘Model
Action’ is ‘Resets’. This means that if the user enters a value outside of the
allowable limits, the model automatically ‘resets’ the user entry, and the reset
entry is displayed in column E under MODEL INPUT. The resulting ‘orange
reset’ creates a red flag error message which must be dealt with.
For details on why orange resets occur, why they must be managed and how, see
Orange Resets in this chapter.
Liquid Pipeline or Liquid Well
The Liquid Pipeline or Liquid Well details group is designed for both pipelines
and wells with a Gas to Liquid Ratio (GLR) ≤ 1000 as measured at stock-tank
conditions of 15º C and 101.325 kPa. These fluid releases contain no free gas –
the solution gas is released from the pool of liquid that forms as the liquid pumps
onto the ground. The release is modelled as a steady jet.
The Liquid Pipeline or Liquid Well details group has two sections. The first
section is open to any user whose initial selection (in SOUR OPERATIONS
TYPE) brought them to this group. The second ‘sub-section’, titled SOURCE
MITIGATION, is only open to those users who selected the analysis type WITH
MITIGATION. When the NO MITIGATON analysis is selected, the source
mitigation inputs are disabled as shown below. For general details on allowable
entry limits and licensee/applicant responsibility for changing default entries in
SOURCE MITIGATION, see Source Mitigation - General in this chapter.
Details specific to the Source Mitigation subsection for the Liquid Pipeline or
Liquid Well group are described later in this section. The following ‘screen
capture’ is for a pipeline.
5 Inputs Page
79
The look changes if a well is selected, as shown below:
5 Inputs Page
80
Notice the Comments column (column D) to the right of the user input column
(column C). It contains additional information on some of the cell requirements.
Depending on the user’s selected SOUR OPERATIONS TYPE (in the
Administrative section of the INPUTS page), certain cells/rows will appear
greyed-out. While some rows pertain only to pipelines and others to wells, most
rows are pertinent to both pipelines and wells.
Field
Phase of Well
Operations?
Is Well Classified as
Critical?
Unique Well Identifier
Well Centre Surface
Location Coordinates,
or Pipeline Segment
From Location
Coordinates
Pipeline Segment To
Location Coordinates
Description
Specify drilling, completion/servicing/workover or
producing/injection/suspended from the dropdown list.
For pipelines, this entry is greyed-out.
Specify Yes or No using the buttons provided. This classification is
determined from the criteria in Guide 56–Schedule 4
For pipelines, this entry is greyed-out.
Specify the unique well identifier as per the well licence or
application.
For pipelines, this entry is greyed-out.
The well surface coordinates or the ‘beginning/upstream’ pipeline
segment (or sub-segment) coordinates, according to the mapping
datum and projection selected in the Administrative inputs section.
These entries are optional and may be left blank.
The ‘ending/downstream’ pipeline segment (or sub-segment)
coordinates, according to the mapping datum and projection
selected in the Administrative inputs section. These entries are
optional and may be left blank.
For wells, these entries are greyed-out.
Licenced Maximum
Operating Pressure
if oil effluent pipeline
For oil effluent pipelines only. For other pipeline substances and
wells, this entry is greyed-out.
The maximum operating pressure (MOP) for which the pipeline is
licensed, kPa (gauge). The Land Use Setback volume calculations
use Licenced Maximum Operating Pressure.
*Pipe Outside
Diameter
The pipe outside diameter, (mm). For wells, this is the tubing (for
the producing phase) or the casing (for the drilling or servicing
phase). For pumping wells with a ‘producing’ well phase, the area
taken up by the diameter of the sucker rod can be ignored; just use
the tubing inside diameter.
*Pipe Wall Thickness
The pipe wall thickness, (mm). For wells, this will be the tubing (for
the producing phase) or the casing (for drilling or servicing phase).
5 Inputs Page
81
Field
Description
For oil effluent pipelines only. For other pipeline substances and
wells, this entry is greyed-out.
Segment Length
if oil effluent pipeline
Length of oil effluent pipeline segment being modelled (m). It must
be one continuous piece of pipe with consistent characteristics such
as described by a pipeline licence line number – governed by ERCB
Directive 056.
Smaller ‘sub-segments’ can be modelled as defined by ‘node’
locations (see Gas Gathering System Analysis - Tutorial in
Chapter 9). Nodes are defined as changes in operating conditions,
physical pipe changes, substance changes, tie-ins, ESD valves and
check valves.
For oil effluent pipelines only. For other pipeline substances and
wells, this entry is greyed-out.
**Equivalent Segment
Length between ESDs,
if oil effluent pipeline
(enter Length or
Volume below)
The equivalent length of oil effluent pipeline between emergency
shut down valves, as determined by the pipeline gathering system
network analysis (m), or by manual calculation. See Chapter 9
Pipeline Gathering Systems, which also describes the manual
calculation.
The Equivalent Segment Length can be the same as the Segment
Length (above) IF, when all flow control valves are in a closed
position, there is no additional pipeline substance material that can
flow into the subject pipeline segment. Under no circumstances can
this Equivalent Segment Length be less than the Segment Length.
The user must enter either this Equivalent Segment Length OR the
Equivalent Cumulative Pipeline Volume (next row down on the
INPUTS page). Do not enter both values. When one value is
entered, the other row is greyed-out.
For oil effluent pipelines only. For other pipeline substances and
wells, this entry is greyed-out.
**Equivalent
Cumulative Pipeline
Volume between
ESDs,
if oil effluent pipeline
(enter Volume or
Length above)
5 Inputs Page
The equivalent cumulative oil effluent pipeline volume between
emergency shut down valves, as determined by the formula
described in the pipeline gathering system network analysis (m3)
see Chapter 9 Equivalent Cumulative Pipeline Volume (between
ESDs).
The user must enter either this Equivalent Cumulative Pipeline
Volume OR the Equivalent Segment Length (previous row on the
INPUTS page). Do not enter both values. When one value is
entered, the other row is greyed-out.
82
Field
Description
**Next to ‘Equivalent Segment Length between ESDs’ and ‘Equivalent Cumulative Pipeline
Volume’, observe that the ‘comment’ cell in column D on the INPUTS page is ‘active’. When
one of the two entries is provided by the user, ERCBH2S calculates the ‘missing’ user entry
and displays the result in column D. If the user entered the Equivalent Segment Length,
column D immediately displays the calculated volume (next to the Equivalent Cumulative
Pipeline Volume). If the user entered the Cumulative Pipeline Volume, column D immediately
displays the calculated length (next to the Equivalent Segment Length between ESDs).
Expected Maximum
Liquid Flow Rate of
Pipeline Fluid [m³/d]
Enter the maximum liquid flow rate (oil and water or other liquid),
[m³/d] for PIPELINE fluids.
For wells, this entry is greyed-out.
Expected Maximum
Gas to Liquid Ratio
The modelled solution gas to liquid ratio (m3) as measured at stock
tank conditions of 15º C and 101.325 kPa (dry gas). If the liquid is
pressurized and heated, the gas release is from the liquid that has
been cooled to near atmospheric conditions. This approach allows
for any gas that stays in the liquid.
For oil effluent pipelines only. For all other pipeline substances and
wells, this row is greyed out.
Licensed Maximum
H2S Concentration
if oil effluent pipeline
The maximum H2S concentration of the pipeline licence (entered in
percent (%). The maximum H2S concentration does not have to
match the reference composition provided in the gas composition
(lower portion of INPUTS page).
Note that emergency planning zone calculations are referenced
from the Expected Maximum H2S Concentration, not the Licensed
Maximum. The Land Use Setback volume calculations use the
Licenced Maximum H2S Concentration.
5 Inputs Page
83
Field
Description
FOR PIPELINES
(DESCRIPTIONS FOR WELLS IN NEXT SECTION)
The highest H2S expected – under any circumstance, entered in
percent (%). This H2S must not be exceeded without first
recalculating the emergency planning zones and proceeding with an
ERP modification/update in accordance with ERCB Directive 071
requirements.
For pipelines where the licensed H2S is not representative of the
actual H2S maximum (due to previous requirements of Directive 056
regarding certain pipeline substances), this H2S entry can be higher
than the pipeline licence.
For pipelines with licences that have representative H2S maximums,
this H2S entry cannot exceed the licensed maximum.
Expected Maximum
H2S Concentration
For all pipelines, this H2S entry can be lower than the licensed
maximum provided it is not exceeded during pipeline operations.
The H2S entered must accommodate all production scenarios – with
consideration given to scenarios where only the highest H2S well is
producing through the pipeline if other wells are shut-in.
The Expected Maximum H2S Concentration does not have to match
the reference composition provided in the gas composition (lower
portion of INPUTS page).
Pipelines with an Expected Maximum H2S below 0.01 % (mole
percent, equivalent to 0.1 mol/kmol or 0.0001 mole fraction or 100
ppm) do not have to be modelled (ERCB Directive 071). If they are
modelled, the results do not need to be submitted to the ERCB.
Note that emergency planning zone calculations are referenced
from the Expected Maximum H2S Concentration, not the Licensed
Maximum.
5 Inputs Page
84
Field
Description
FOR WELLS
(DESCRIPTIONS FOR PIPELINES IN PREVIOUS SECTION)
The highest H2S possible (appropriate to the phase of well operation
being modelled), entered in percent (%).
For new wells, this is the H2S provided in the well licence
application.
Expected Maximum
H2S Concentration
For all existing wells, it is the highest possible H2S from any
formation capable of flowing to surface. For pumping wells, it is the
highest possible H2S from any formation being pumped to surface.
For injection or disposal wells, it is the highest possible H2S that can
be released at the surface.
The Expected Maximum H2S Concentration does not have to match
the reference composition provided in the gas composition (lower
portion of INPUTS page).
Wells with an H2S below 0.01 % (mole percent, equivalent to 0.1
mol/kmol or 0.0001 mole fraction or 100 ppm) do not have to be
modelled (ERCB Directive 071). If they are modelled, the results do
not need to be submitted to the ERCB.
Note that emergency planning zone calculations are referenced
from the Expected Maximum H2S Concentration.
5 Inputs Page
85
Field
Description
The volumetric H2S release rate at reference conditions (m3/s at
15ºC and 101.325 kPa). While surface rates are preferred (more
representative), sand-face rates can be entered (less representative,
but more conservative because they will be somewhat higher).
For new wells with an ERCB approved pre-submission release rate,
enter the pre-approved rate appropriate to the phase of well
operations being modelled.
H2S Release Rate of
Well
(Cumulative if Multizone) (m3/s)
For new wells without an ERCB approved pre-submission release
rate, enter the cumulative release rate estimate provided in the well
licence application – appropriate to the phase of well operations
being modelled. If the well has potential to encounter both gas and
liquid H2S bearing formations (e.g. one zone is gas while another is
liquid), the user must model the Cumulative H2S Release Rate using
only the Gas Well portion of the INPUTS page.
For existing (drilled) wells, enter a cumulative release rate based on
all formations capable of flowing to surface.
Note - ERCBH2S is designed for calculating ERP zones, not well
release rates. Requirements/guidelines for calculating well release
are in other ERCB publications.
The minimum liquid temperature in degrees Celsius (ºC) should be
entered.
Expected Minimum
Liquid Temperature
If the user entry cell is left blank a default value of 5°C (ground
temperature), is used. The allowable temperature range is shown to
the right of the INPUTS page, in columns H and I. Observe that in
column J, the ‘model action’ for this row is ‘resets’. This means that
if a user entry is outside the allowable range, an ‘orange reset’ will
be applied. To understand more about orange resets (and why a
user must change their entry to remove them) see Orange Resets in
this chapter.
Liquid Pipeline and Liquid Well Group - Source
Mitigation Sub-section
If the WITH MITIGATION analysis was selected in the Administrative section
of the INPUTS page, two more parameters are available for entry to manage
‘liquid well’ emergency response planning, and one more entry for ‘liquid
pipeline’ emergency planning.
5 Inputs Page
86
The WITH MITIGATION analysis entries (see below) include mitigation
controls for Surface Controlled Sub-Surface Safety Valves (SCSSSV) – a yes/no
entry (producing wells only), and time from initial release until ignition or stop
flow (input value for pipelines or wells).
For additional information on a licensee/applicant’s responsibility when changing
a default entry in the SOURCE MITIGATION section, see Source Mitigation Licensee/Applicant Responsibility in this chapter.
When to Change the Default Settings
A user should only change the default settings (over-ride the default settings) in
this group IF the licensee can perform/coordinate the following actions within the
time frame indicated in this section of the model:
•
detect the release,
•
contact the operator (for wells, consider whether or not it is a manned
operation),
•
travel to the site (for wells, again consider whether or not it is a manned
operation),
•
verify a release is occurring (for wells, again consider whether or not it is
a manned operation), and
•
perform a prescribed, pre-planned action that prevents additional H2S from
being released (such as igniting the well or pipeline, closing a valve, or
‘drawing down’ a pipeline).
Unless the licensee can perform the above actions in less time than shown as a
default entry for this group, this field should be left blank. Note that for wells, the
default setting for ‘Time from initial release until ignition or stop flow’ changes
with the phase of well operation – which indicates if the site is manned or unmanned (subsequently affecting the time to implement mitigation measures). In
addition, producing wells with a Surface- Controlled Sub-Surface Safety Valve
(SCSSSV) have a significantly reduced default setting. To change the SCSSSV
option, a ‘with mitigation’ analysis must be selected.
For pipelines, the default entry and the allowable value range for ‘Time from
initial release until ignition or stop flow’ remain constant. The SCSSSV row is
greyed-out for pipelines.
5 Inputs Page
87
Note that for liquid pipelines, the duration of the release is a function of whether
the release has been manually detected - since emergency shutdown valves are not
normally employed on this type of pipeline. Consequently, production pumps
continue at capacity until the release is detected. For this reason, ERCBH2S
assumes the maximum modelling time of 12 hours before the leak is detected.
Durations longer than 12 hours will not impact the size of the ERP zones. If sitespecific controls are available to limit this time, a WITH MITIGATION analysis
allows the user to change the Time from Initial Release till Stop Flow or
Ignition.
In all cases where SOURCE MITIGATION default values are changed, the
ERCB may request documentation to support a licensee’s entries.
Note that while some planning zones sizes decrease with
changes to the source mitigation time, significant EPZ
changes are not realized until mitigation time is reduced
to 3 hours (180 minutes) or less.
The ERCB may request documentation that supports a
licensee’s non-default Time from Initial Release
until Ignition or Stop Flow values
Liquid Pipeline or Liquid Well Group - Orange Resets
The lower (min.), upper (max.) allowable values for ‘Time from initial release
until ignition or stop flow’ change with the phase of well operation, and with the
presence of a SCSSSV. For pipelines, they remain the same (the SCSSSV row is
greyed-out for pipelines).
The allowable limits are shown to the immediate right on the INPUTS page, in
columns H and I. Observe that in column ‘J’ the ‘Model Action’ is ‘Resets’. This
means that if the user enters a value outside of the allowable limits, the model
automatically ‘resets’ the user entry, and the reset entry is displayed in column E
under MODEL INPUT. The resulting ‘orange reset’ creates a red flag error
message which must be dealt with.
For details on why orange resets occur, why they must be managed and how, see
Orange Resets in this chapter.
5 Inputs Page
88
Sour Gas Composition
In the Sour Gas Composition input section, enter a representative composition of
the sour gas stream according to a reference analysis. The data format is in
component molar fractions input on a dry basis. For the analysis should be for the
gas phase, at standard conditions of 15º C and 101.325 kPa – dry basis.
If a well has multiple zones, if possible - choose the zone with the highest H2S.
Otherwise, as long as the analysis composition is representative of at least one of
the zones, differences from one analysis to another make little difference in the
calculated size of the planning zones. ERCBH2S adjusts the user entered analysis
H2S value to equal the H2S entered for modelling purposes (in the Gas Pipeline,
Gas Well, or Liquid Pipeline or Liquid Well section of the INPUTS page – the
Expected Maximum H2S). All other composition components are pro-rated
according to their new fractional contribution to the total (renormalized). The
adjusted analysis can be immediately viewed on the ERP summary page because
the calculations performed by Excel – no ERCBH2S program ‘run’ commands are
needed for this conversion. All ERCBH2S calculations will reference the adjusted
analysis.
Representative gas composition requirements are as described in other current
ERCB publications, such as Directive 056 and Directive 040.
Data entered must be normalized; that is, the molar fractions of the listed
components must sum to 1.0. ERCBH2S will not correct the data for you. A
warning error next to the will appear when values are not normalized as shown in
the illustration above. This warning is used to prevent user entry errors if gas
components are skipped or miss-entered. Sometimes, due to rounding, a gas
analysis may add up to slightly more than 1. In this event, subtract the ‘extra’
mass from whichever component has the highest mole fraction, and entered the
adjusted values.
5 Inputs Page
89
If the maximum H2S value specified in the Details section is
different than the value specified in the gas composition field,
ERCBH2S readjusts the composition specified to use the
specified value. The stream composition will be renormalized
and then this new composition will be used for all subsequent
calculations.
Advanced User Selected Case
For ERCB submission, the default entries in this section must not be changed.
User over-ride of the default entries creates a red flag error message that will
remain attached to the calculation results.
This section provides an opportunity for the advanced technical user to investigate
intermediate calculations and mitigation strategies for a selected meteorological
and/or Gas Pipeline Release Hole Size (Fraction).
Field
Description
Ambient Wind Speed at measurement
height, Uref
Stability Class
Pipeline Release Hole Size Fraction,
Ae/Ap
5 Inputs Page
Ambient wind speed, in m/s. The DEFAULT value is 2.0
m/s.
Atmospheric turbulence conditions as defined by Pasquill
Gifford stability classes. The DEFAULT stability is
Class F (also represented by a numerical value of 6).
The Pasquill-Gifford scale is:
1 = A: very unstable (very turbulent)
2 = B: moderately unstable
3 = C: slightly unstable
4 = D: neutral conditions (breezy, overcast)
5 = E: moderately stable
6 = F: very stable (calm)
7 = none (default)
The Ae/Ap ratio entered includes the discharge coefficient
due to compressibility effects at the exit orifice.
90
All rows in the User Selected Case group have pre-determined entry limits shown
to the immediate right on the INPUTS page, in columns H and I. Observe that in
column ‘J’ the ‘Model Action’ is ‘Resets’. This means that if the user enters a
value outside of the allowable limits, the model automatically ‘resets’ the user
entry, and the reset entry is displayed in column E under MODEL INPUT.
For details on why orange resets occur, why they must be managed and how, see
Orange Resets in this chapter.
ERCBH2S normally iterates through 54-combinations of
stability class and wind speed for 11 pipeline hole size
fractions to calculate the largest ERP zones (i.e., worstrelease hazard distances) for each of 54 different
meteorological conditions.
To enable the user to perform ‘what-if’ analyses, a user
selected case may be entered to override the automatic
search. These inputs are for the technical user only.
Default over-rides in the User Selected Case group are
not acceptable for ERCB submission. A red flag error
message will be attached to the calculation results.
5 Inputs Page
91
6.
Calculation Pages
Calculation pages have a yellow sheet tab. Intermediate calculation pages are not
displayed for normal operation of the ERCBH2S program. A list of the
intermediate calculation pages is provided in Chapter 4 under “User-Interface”.
Intermediate calculation pages are not displayed for
normal operation of the ERCBH2S program operation.
The Hide Technical Pages switch can be toggled
to display these pages in the ERCBH2S template file.
Some of the intermediate calculation pages are general in nature and are displayed
whenever the Hide Technical Pages toggle is deactivated. Other pages are
only visible depending on the assessment flavour. For example, if the ERCBH2S
flavour has been set to SOUR GAS PIPELINE, then the SOUR GAS WELL
and SOUR OIL related pages will remain hidden.
Common Pages
CONSTANTS
The CONSTANTS page has a green sheet tab for inputs because it contains a
variety of ERCB mandated default input values as well as physical and chemical
constants required for the calculations. There are many parameters in ERCBH2S
that require advanced scientific expertise and judgement. The selected default
values are mandatory parameters for ERCBH2S to avoid arbitrary selection while
providing a common assessment basis for ERP zones calculations. The values on
this page are security protected and are not editable.
ERCB Default Inputs
The following table describes the parameters that have been selected by the
ERCB as default entries.
6 Calculation Pages
92
Source
Description
Release Angle
D Plane Drag Coefficient, CD
Water Content of Sour Gas
Meteorology
Ambient Temperature, Ta
6 Calculation Pages
Orientation of the source release. HORIZONTAL means that the
release is parallel to the ground surface. VERTICAL means that
the release is directed upwards, away from the ground surface.
The DEFAULT is horizontal
Drag Coefficient is an empirical factor to account for losses of
momentum due to the jet release interactions with surfaces, such
as the ground or obstacles. The Drag Coefficient can affect the
dispersion results, especially in the near field, because of the
momentum loss, plume rise and travel time effects. The drag
coefficient is between 0 and 1. The default value is 0.5. Producing
wells are typically free of well site infrastructure; therefore 0.25 is
used as the default.
The water (moisture) content in the gas stream is specified.
The DEFAULT water content of gas is 0 mg of water per standard
m3 of wet gas.
Description
Ambient air temperature. The DEFAULT value is 5°C, a typical
93
annual average temperature in Alberta.
Relative Humidity, rh
Ambient Measurement Height za
Surface Roughness Height, Zo
Exposure
Planning Endpoint, TLeCp
(TLeC=Toxic Load Equivalent
Concentration)
Planning Endpoint Duration tp
Response Endpoint, TLeCr
(TLeC=Toxic Load Equivalent
Concentration)
Response Endpoint Duration tr
Concentration Exponent
for Toxic Load, n
Relative humidity of air. The DEFAULT value is 60 %.
Height at which the wind speed is measured.
The DEFAULT value is 4 m to be consistent with plume dispersion
parameterization used in ERCBSLAB.
Surface roughness height is an effective height of surface
conditions as they affect atmospheric turbulence. Typical values
range from 0.001 m (very smooth) to 2.0 m (hilly or urban).
The DEFAULT value is 0.10 m.
Description
Concentration used in calculating the equivalent toxic load
threshold for planning purposes. The DEFAULT value is 100 ppm.
Duration used in calculating the equivalent toxic load threshold for
planning. The DEFAULT value is 60 minutes.
Concentration used in calculating the equivalent toxic load
threshold for response purposes. The DEFAULT value is 100 ppm.
Duration used in calculating the equivalent toxic load threshold for
Response. The DEFAULT value is 150 minutes.
Exponent used in calculation of toxic load.
The DEFAULT value is 3.5.
Building Air Changes per Hour, ACH
Building air changes is the ventilation rate of the building and is
used to estimate indoor H2S concentrations for sheltering. Values
range from 0 (no exchange) to more than 35 (lots of exchange,
automobile). For buildings, the range is 0.1 to 5 building air
changes per hour.
The DEFAULT value of 0.5 is for leaky residential buildings.
Maximum Exposure Time
Maximum duration, exposure and averaging time for the release.
The DEFAULT value is 10800 seconds (3 hours).
Reference Total Fluctuation Intensity
iref
Reference Time for Reference Total
Fluctuation Intensity
Gas Pipeline
Gas Pipeline Release Height, hs
Pipe Absolute Roughness
Blowdown Inertial Delay Factor, Ki
Gas Well
Gas Well Release Height, hs
6 Calculation Pages
A measure of how much the concentration varies from the average
for a given averaging time. The DEFAULT value is 0.25.
The DEFAULT value is 180 seconds (3 minutes)
Description
Source height for sour gas pipeline releases. The DEFAULT value
is 0 m.
Roughness of the inside wall of the pipeline.
The DEFAULT value is 0.05 mm.
Constant used in calculations to determine the mass release rate.
The DEFAULT value is 0.5.
Description
Height from which the well release occurs, measured in m.
The DEFAULT value is 1 m.
94
Stagnation Temperature, Ti
Liquid Pipeline/Well
Liquid Release Height, hs
Stagnation temperature of the wellhead release includes the
temperature rise that would occur if the flowing gas were stopped to
a velocity of zero. The DEFAULT value is calculated based upon
the average of the ideal gas properties of the release to result in a
dense release and the typical ground temperature of 5 °C.
Description
Source height for sour liquid pipeline/well releases.
The DEFAULT value is 0 m for pipelines and 1 m for wells.
See ERCBH2S document Volume 1: Technical Reference Document
and ERCBH2S document Volume 2: Emergency Response Planning
Endpoint for more information.
Physical Constants
ERCBH2S makes use of several chemical-physical constants. The values used in
ERCBH2S, ERCBFLASH and ERCBSLAB are listed below.
ERCBH2S also calculates the thermodynamics for moist air as listed below.
6 Calculation Pages
95
SHARED
The SHARED page contains gas calculations that are common to all ERCBH2S
analysis flavours. The page includes calculations of chemical/physical properties
and gas composition. The values on this page are security protected and are not
editable.
ERCBFLASH
The ERCBFLASH page lists the inputs to the ERCBFLASH program. The
ERCBFLASH program calculates ‘real gas’ chemical/physical properties for the
well or pipeline release exit conditions. Real gas properties can vary significantly
from ‘ideal gas’ properties due to extreme conditions such as pressure or
temperature. The values on this page are security protected and are not editable.
ERCBFLASH OUTPUT
The ERCBFLASH OUTPUT page displays the ERCBFLASH program output
information. The output consists of a listing of the calculated ‘real gas’
properties. The values on this page are security protected and are not editable.
ERCBSLAB
The ERCBSLAB page lists the inputs to the ERCBSLAB program for H2S
dispersion modeling. A note at the top of the page indicates if the run is dense or
passive/ buoyant. The values on this page are security protected and are not
editable.
The ERCBSLAB input file is similar to the original US EPA
Slab program input file. The input variables that are different
than the original program are highlighted by bold typeface
ERCBSLAB OUTPUT
The ERCBSLAB OUTPUT page displays output from the ERCBSLAB program.
The output from ERCBSLAB is a modified version of the original USEPA SLAB
format, but maintains the same concepts. The values on this page are security
protected and are not editable.
6 Calculation Pages
96
The ERCBSLAB output file can be produced by activating the
ERCBSLAB debug switch ERCBH2S→
Setup→ERCBSLAB Debug. The output file is written to
the default folder.
TOX OUTPUT
The TOX OUTPUT page displays the ERCBSLAB program secondary output
file for toxic load calculations for the User Selected Case of meteorology
and pipeline release fraction. The listing shows concentrations and toxic load
equivalent concentrations with distance for each of the indoor and outdoor,
planning and alert criteria combinations. The values on this page are security
protected and are not editable.
The ERCBSLAB secondary output ToxOutput file can be
produced by activating the ERCBSLAB debug switch
ERCBH2S→ Setup→ERCBSLAB Debug. The output
file is written to the default folder.
MAX OUTPUT
The MAX OUTPUT page displays the ERCBSLAB program secondary output
file for toxic load calculations for all screening meteorology cases and the user
selected pipeline release fraction. The listing shows the maximum concentrations
and toxic load equivalent concentrations with distance for each of the indoor and
outdoor, planning and alert criteria combinations. The values on this page are
security protected and are not editable.
The ERCBSLAB secondary output MaxOutput file can be
produced by activating the ERCBSLAB debug switch
ERCBH2S→ Setup→ERCBSLAB Debug. The output
file is written to the default folder.
METMATRIX
The METMATRIX page displays output from screening matrix calculations.
That stability class and wind speed values specified on the INPUTS page have a
significant effect on the calculated hazard distances. To help efficiently examine
the worst-release hazard distances incurred by varying the stability class and wind
speed values over the possible combinations, the various hazard distances are
6 Calculation Pages
97
calculated and presented in tabular format. In total 54-combinations of stability
class and wind speed based on the regulatory screening matrix are calculated.
The calculation matrix is displayed on the METMATRIX page. If the Pipeline
flavour is selected, then the METMATRIX page will also display the results of
the Ae/Ap Ratio Search for each meteorological condition.
HAZARD DISTANCES
The HAZARD DISTANCES page displays the calculation matrix and predicted
output of the Dispersion Condition Probability Weighted Hazard Distance
that supports the calculated distances for the Planning and Response zones.
The Dispersion Condition Probability Weighted Hazard Distance is a weightedaveraged value of 54 Worst-Release Hazard Distances, which is calculated by
multiplying the hazard distance in each of 54 categories by fraction of time that
each meteorological condition occurs.
The results of Maximum of Primary and Secondary Hazard Distances from the
METMATRIX page are displayed as the Worst-Release Hazard Distances in the
HAZARD DISTANCES page. The model uses the Average Probability of PG
Stability Class and Wind Speed in Alberta (historical data from Alberta
Environment) to determine the fraction of time that each of the dispersion
conditions occurs and weights the Worst-Release Hazard Distances to produce
the Dispersion Condition Probability Weighted Hazard Distance.
Note: The Worst-Release with Worst-Dispersion Distance is also displayed in the
HAZARD DISTANCES page. However, these values are not displayed in the
ERP SUMMARY page.
The Hazard distances are not rounded, but show distances
to a resolution of 1 m. The ERP planner should use these
distances in conjunction with other planning information
(egress routes, population density, etc...) and finalize the
ERP zones to a logical site-specific distance.
Although the ERCBH2S models may predict Hazard
distances greater than 30000 m (30km) the maximum
suggested EPZ, IIZ, or PAZ is 30000 m (30km). This is the
largest distance to where the model predictions can be
applied.
6 Calculation Pages
98
Gas Pipeline Pages
SOUR GAS PIPELINE
The ERCBH2S calculation pages for each sour operations type are divided into
the following sections:
Section Title
Description
Release Description
General data describing pipeline segment and factors
needed for subsequent calculations.
Source Calculations
Input and outputs from ERCBFLASH used to calculate
the Mass Release Rate and Duration and Receptor
Exposure.
Receptor Exposure Calculations
From ERCBFLASH
Exposure calculation data, as defined by user and
release.
Output data from ERCBFLASH. This information will
only be updated after the program has been run.
Data calculated from real fluid
properties
Compares choked flow properties to ERCBSLAB
inputs to determine flow type.
Buoyancy Flux
A comparison of buoyancy values using different
methods to ensure consistency.
Inputs to ERCBSLAB
Jet Expansion Planes, Both Jets
Drag Test Calculations
Input data for the ERCBSLAB program. Uses the
second ERCBFLASH data.
Comparison of gas stream properties for jet expansion
planes (I, E, Q, D and R). R plane data is used as
input for ERCBSLAB.
This section allows the user to determine what drag
coefficient to use based on a velocity or velocity ratio.
It also gives the force required to slow down and
change directions of the jet. Note the default drag
coefficient can not be changed by the user.
The calculations are security protected and are not editable. These calculations
are displayed in order to provide information about the calculation process and aid
in understanding the theory behind the models. You may note that some cells
have the labels “not used” beside them in the page. This is because although
ERCBFLASH calculates these properties they are not used in the ERCBH2S
program. They are presented here for your information only.
The SOUR GAS PIPELINE page uses the input data to calculate the physical
characteristics of the release. Refer to the section on Gas Pipeline Calculation
Process for a general overview of the calculation process. The approach and
6 Calculation Pages
99
assumptions involved in the estimates are described in Volume 1 - Technical
Reference Document.
ESD CLOSURE
The amount of mass released during a pipeline failure can be a function of the
spacing of emergency shut-down (ESD) valves. The blow-down of the pipeline
takes some time for the pipeline to depressurize. The pipeline does not
depressurize uniformly, but in a non-linear fashion from the release location. It
may take some time before the pressure at the location of the ESD is sufficient to
trigger the closure of the valve and will also depend on the pressure set-point of
the valve and its sensitivity. The time required for the triggering of the ESD is
estimated on the ESD Closure page. See also the description of the ESD
Closure on page 49.
AeAp-ITERATION
The AeAp-ITERATION page shows the calculation matrix used to determine
the sensitivity of the ERP Zones for the meteorological case (single wind speed
and stability class) tested and Ae/Ap ratios listed in the table. The results of the
exit area ratio are displayed in a graph below the table showing the variation of
ERP zones with change in Ae/Ap ratio. See also the description of the Ae/Ap
calculation process on page 50.
Gas Well Page
SOUR GAS WELL
The ERCBH2S calculation page sections were described in the SOUR GAS
PIPELINE section of this chapter. The SOUR GAS WELL page uses the input
data to calculate the physical characteristics of the release. Refer to Gas Well
Calculation Process in Chapter 4 for a general overview of the calculations on this
page. The approach and assumptions involved in the estimates are described in
Volume 1 - Technical Reference Document.
6 Calculation Pages
100
Liquid Pipeline/Well Page
SOUR LIQUID
The ERCBH2S calculation page sections were described in the SOUR GAS
PIPELINE section of this chapter. The SOUR LIQUID page uses the input data
to calculate the physical characteristics of the release. Refer to the section on
Liquid Pipeline and Liquid Well Calculation Process for a general overview of the
calculation process. The approach and assumptions involved in the estimates are
described in Volume 1 - Technical Reference Document.
6 Calculation Pages
101
7.
Output Pages
Output pages have a pink sheet tab. Several other output pages are provided and
provide a varying level of sophistication for the technical user. These pages are
briefly described below:
Page Name
Purpose
Description
ERP SUMMARY
Output
HAZARDS
Tabular
Summary
Summary of Release Description, User Selected Case Hazard
Distances, Maximum of Screening Hazard Cases ERP Zones.
GRAPH-MET
Graphic
Summary
Tabular and graphical representation of the METMATRIX data. Hazard
distances for the range of meteorological conditions and wind speeds.
Presented in tabular and graphical format. The maximum computed
distance is highlighted.
GRAPH-ERCBSLAB(x)
Graphic
Summary
Graph showing how variables change as the release moves away from
the source.
GRAPH-STEADY(x)
WELL and LIQUID
Graphic
Summary
Graphical representation of the TOX OUTPUT and MAX OUTPUT
concentrations. The Planning and Alert Criteria are highlighted on the
graph
GRAPH-TRANSIENT(x)
PIPELINE ONLY
Graphic
Summary
Graphical representation of the TOX OUTPUT and MAX OUTPUT
concentrations. The Planning and Alert Criteria are highlighted on the
graph
Summary of Inputs and Emergency Response and Planning Zones.
This page to be included for each well and pipeline segment in the
Emergency Response Plan.
ERP SUMMARY
The ERCBH2S program results are summarized on a single output page called
ERP SUMMARY that displays an executive summary of the information
displayed on the INPUTS and HAZARD DISTANCES pages. It lists
administrative data, the calculated ERP zones for the pipeline, well or liquid
release, and a graphic that represents the relative relationship between calculated
distances.
The red flags may continue to appear if the User has
specified a Gas Pipeline Release Hole Size Fraction on the
INPUTS page. Delete the entry and run Calculate EPZ to
remove the red flags.
7 Output Pages
102
The Advanced User Selected Case on the INPUTS page
can include the wind speed and stability class but not the
Pipeline Release Hole Fraction. Delete the wind speed and
stability class and run Calculate EPZ to remove the
red flags.
The Administrative and Facility Inputs table displays information that was entered
on the INPUTS page. Next the Gas Pipeline Details, Gas Well Details
or Liquid Pipeline/Well Details information that was entered on the
INPUTS page is echoed. A sample is provided below:
7 Output Pages
103
The Results table (see below) displays the calculated Land Use Setback H2S
release rate or volume (if applicable), the Level Designation (if applicable) and
the compressibility factor used based on user input licenced conditions. The
Existing EPZ (user entry on the INPUTS page – Administrative) and the
Normograph EPZ calculation (based on the H2S release rate or volume) are also
provided.
The predictions from the Worst-Release with Averaged-Dispersion Distances on
the HAZARD DISTANCES page are displayed graphically on the ERP
SUMMARY page (see example below).
The graphic displays four predicted distances and represents several concepts:
•
IIZ (Initial Isolation Zone) is colour coded in pink. Within this circle,
sheltering-in place may not be a viable public protection measure; all
persons within this zone should be evacuated immediately. Therefore
sheltering-in place within this zone can only be considered a
temporary response measure. It is based upon the indoor toxic load
criteria.
7 Output Pages
104
•
EPZ (Emergency Planning Zone) is a colour coded in orange. It is the
distance requiring specific emergency response planning, preparedness
and response and is based upon the outdoor toxic load criteria. The
ERCBH2S EPZ must include all people within this radius. The final
EPZ submitted to the ERCB will reflect other considerations such as
egress and local population densities.
•
PAZ (Protective Action Zone) is a pie-wedge area within the EPZ
with a red dash border. It indicates an area downwind of a hazardous
release where outdoor pollutant concentrations may result in lifethreatening or serious and possibly irreversible health effects on the
public. The PAZ endpoint is defined as a 130 ppm concentration of
H2S over a 60-minute exposure time. The PAZ endpoint is protective
of unconsciousness. The PAZ is an emergency response distance and
therefore is dependent upon the meteorology (wind blowing to) at the
time of the incident and must be assessed frequently for change of
direction.
The width of the sectors in the graphic is for presentation
purposes only. The width of the sector during emergency response
must be determined by responders based on field measurements.
The ERP Zones are the Worst-Release with Averaged-Dispersion Distances
from the HAZARD DISTANCES page. For reference, the faction of time that
of each of the dispersion conditions occurs is displayed in the Average Probability
of PG Stability Class and Wind Speed in Alberta table on the HAZARD
DISTANCES page.
Each Emergency Planning and Response zone submitted
as part of an ERP must reflect site-specific features such
as population density, topography, access/egress routes
and any other identifiable factors that may affect timely
implementation of emergency response procedures. Thus
each zone distance calculated by ERCBH2S may require
further consideration for planning or during response. The
implied shape of the combined planning zones
represented by the ERCBH2S outputs, therefore, is a
schematic simplification for display purposes.
Erasing Calculation Results
Calculation results (outputs) on the ERP SUMMARY page can be erased by
selecting “Erase all output fields’ from the technical sun-menu as shown below or
7 Output Pages
105
by selecting the ‘Erase all output fields’ button
from the button bar. This
command also erases outputs from other ERCBH2S ‘Summary/Graphics’ pages,
but does not erase outputs stored on the BATCH page.
HAZARDS
The Hazards page displays output for a single selected meteorological condition
results and the EPZ screening meteorological results that supports the calculated
distances for the Planning zones.
The Release Description displays some of the input information and
calculated properties of the defined case. The release type indicates whether the
release was modelled as transient blow-down (pipeline) or a constant rate release
(well).
User Selected Case
The third table, titled Selected Meteorology Case, displays the hazard zone
distances for both planning and alert limits for the single stability and single wind
speed case. An example is shown below.
7 Output Pages
106
ERCBH2S-Well & Liquid
The Ae/Ap ratio columns are not relevant for the ERCBH2SWell or Liquid flavours.
The Hazard distances are not rounded, but show distances
to a resolution of 1 m. The ERP planner should use these
distances in conjunction with other planning information
(egress routes, population density, etc...) and finalize the
ERP zones to a logical site-specific distance.
Although the ERCBH2S models may predict Hazard
distances greater than 30000 m (30km) the maximum
suggested EPZ, IIZ, or PAZ is 30000 m (30km). This is the
largest distance to where the model predictions can be
applied.
This table displays results for a single selected meteorological case (in the
example shown above: stability Class F and wind speed 2 m/s). The predictions
show in the example are for the Wind Speed and Stability Class specified in the
User Selected Case input group on the INPUTS page. The wind speed and
stability class columns in the Primary Zone section have identical values for each
row based upon the selected meteorology entered and are therefore disabled
(greyed) to avoid confusion.
The Secondary Hazard columns will display data for a situation that can
sometimes occur if the release is initially near the ground and then rises further
down wind (see example below). When a secondary hazard is predicted the table
will populate the Secondary Hazard zone columns and colour code the
prediction (warning-orange). Otherwise, these columns will be blank as shown
above. For more information on the calculation of secondary zones, see
Volume 1: Technical Reference Document. In the example below, EPZ
is shown to have a Secondary Hazard zone with distance prediction having
both a primary distance (1547 m) and a secondary distance (1560 m).
7 Output Pages
107
The classification of Near Field and Far Field densities, displayed in the Source
Conditions table are determined by the density of the release relative to the air
density.
• Near field characteristics are defined by the exit conditions of the
release. The plume trajectory is dominated by the initial conditions.
• Far field is defined when an infinite amount of air is added to the
release. At this point, the plume has reached the final rise.
There is a transition from near-field to far-field for each release, which depends
on the release properties.
Gas Density
is greater than
Air Density
Gas Density
Near Field
(density at exit)
Initially dense
Initially buoyant
Far Field
(equivalent density)
Dense
Buoyant
Classification
is less than
Air Density
Maximum of Screening Hazard Cases
The data in this table is only updated when the Calculate EPZ command has
been run. The Calculate EPZ command searches through all the
meteorological cases and selects the largest predicted hazard distance. As a
result, each row of the Maximum of Screening Hazard Cases table may have
different values in the Wind Speed or Stability Class columns. If there is a
Secondary Hazard detected, these values will be displayed in the Secondary
Hazard columns.
7 Output Pages
108
GRAPH-MET
Once the Calculate EPZ command has been run, the Maximum of the
Screening Hazard Cases section of the HAZARDS page will be updated. The
GRAPH-MET page contains a graphic representation of the METMATRIX
page. The user may select the desired data to display using the drop down list.
The table and the graph are then populated with corresponding data from the
METMATRIX page. An example of the table and graph are shown below.
Many of the matrix cells are greyed (disabled). Within the Pasquill-Gifford (PG)
meteorological classification, these combinations of wind speed and atmospheric
stability have been demonstrated to not occur. Additionally, within Alberta,
Class A stability with winds above 1 m/s does not occur; and therefore have been
removed from the ERP screening matrix for selection of the maximum hazard
distances.
Also, many studies have shown that for ground-based releases, the regulatory
dispersion parameters do not account for plume meandering during low wind
speed stable dispersion conditions resulting in unreasonably high predictions.
Therefore the predictions for Class E at 1 m/s and Class F below 1.5 m/s, have
been removed from the ERP screening matrix for selection of the maximum
hazard distances.
The graph shows the sensitivity of the hazard distances to the meteorological
conditions as a family of curves grouped by atmospheric stability class. Although
this example shows relatively well behaved (i.e., explained curves) the family of
curves can often show complex relationships; in which case, careful consideration
of plume buoyancy, plume rise and dispersion must be included in the
interpretation.
The screening matrix calculation must be performed and
included as part of your submission to the ERCB.
7 Output Pages
109
Wind speeds above 1 m/s for Class A do not occur at
meteorological stations within Alberta, thus these
meteorological conditions are removed from ERP zone
calculation.
The effect of meandering is underestimated in the turbulence
parameterization for 1 m/s Class E and F and 1.5 m/s Class F,
thus these meteorological conditions are removed from ERP
zone calculation.
7 Output Pages
110
Calculations for Scenario: EXAMPLE|1-2-3-4 W5M|
Hazard Distances for Meteorological Matrix
Outdoor Toxic Load Equivalent H2S Concentration
(100 ppm for 60 minutes with n= 3.50)
EPZ1: Outdoor Planning (m)
Wind Speed (m/s) Class A Class B Class C Class D Class E Class F
1
808
54
1422
2225
3370
1005
1.5
619
2155
1161
3146
1720
2454
2
527
818
2812
3951
3008
4132
2.5
464
725
1231
3683
5048
7129
3
423
655
1115
1593
4776
7275
3.5
605
1016
1478
2960
7253
4
554
952
1368
1952
7268
4.5
526
887
1269
1850
5
499
832
1208
1747
8
649
933
10
572
819
15
657
20
557
windspeed that is unlikely for the given stability class
meandering of ground based release underestimated
Maximum Distance=7275m
EPZ1: Outdoor Planning (m)
Class A
Class B
Class C
Class D
Class E
Class F
8000
Maximum Distance=7275m
Distance to Hazard Level (m)
7000
6000
5000
4000
3000
2000
1000
0
0
5
10
15
20
Wind Speed (m/s)
7 Output Pages
111
GRAPH-ERCBSLAB (x)
The GRAPH-ERCBSLAB (x) page presents a graphical display of some of the
technical values calculated by ERCBSLAB. The graph shows the change in
various parameters as the release moves away from the source (instantaneously
spatially averaged cloud parameters). The values for this graph are taken from the
ERCBSLAB Output page. An example is shown below.
The graph displays the information summarized in the following table.
Symbol
Parameter
Units
zc
Profile centre height:
the height above ground of the centre of the
vertical concentration profile.
m
h
Box height:
vertical dimension of the simplified
concentration profile.
m
bb
Box half width:
the half-width of the across-wind dimension of
m
7 Output Pages
112
Symbol
Parameter
Units
the simplified concentration profile.
Ri
Absolute value of Richardson number:
ratio of strength of buoyancy forces compared
to mechanical mixing forces. The Richardson
number can be used as one indicator of the
likelihood that a plume will rise or disperse
parallel to the ground surface.
Unit-less
C(x,0,zp=0)
Time averaged volume concentration on plume
profile centre line and ground level representing
the maximum concentration at each x location
downwind and ground level.
m3 source gas /
m3 mix
C(x,0,z)
Time averaged volume concentration on plume
profile centre line and profile Zc height above
ground representing the maximum
concentration at each x location downwind.
m3 source gas /
m3 mix
GRAPH-TRANSIENT(x)
The GRAPH-TRANSIENT(x) page shows a graph for variation in the toxic
load equivalent concentrations and time averaged concentrations (both indoor and
outdoor) as a function of downwind distance from the release source for the
selected meteorology (top) and for meteorological conditions (bottom). The
distance at which these values exceed the endpoints for planning and alert levels
are indicated by a circle or a square, respectively. An example of the transient
maximum concentrations graph for the selected and all meteorological conditions
is shown below.
The yellow line indicates where the release will be after 180 minutes traveling at
the specified wind speed (in this case, 2 m/s).
Two peaks may occur in the graphs for some of the
predictions. The primary peak (near field or nearest the
source) may occur because: the plume is initially dense; or
the release is near the ground and horizontal. The
secondary (furthest downwind) peak may occur because the
plume reached its final rise height (buoyant plumes) and
dispersion conditions result such that the ground level
concentrations are increasing from the lofted plume.
Secondary peaks flagged by ERCBH2S program must
be carefully considered by the planner.
7 Output Pages
113
7 Output Pages
114
GRAPH-STEADY(x)
The GRAPH-STEADY(x) shows the variation in the toxic load equivalent
concentrations and time averaged concentrations (both indoor and outdoor) as a
function of downwind from the release source for the selected meteorology (top)
and for meteorological conditions (bottom). The distance at which they exceed the
endpoints for planning and response are indicated by a circle or a square,
respectively. An example of a GRAPH-STEADY(x) result for selected and all
meteorological conditions is shown below.
The yellow line indicates where the release will be after 180 minutes traveling at
the specified wind speed (in this case, 2 m/s).
An example of the hazard distances for all meteorological conditions is shown.
The figure was generated from the same conditions as the selected meteorology.
The meteorological conditions that lead to the maximum concentration at a
distance are not related to the meteorological conditions that lead to the maximum
concentration at an adjacent location. Therefore, the predictions are not
necessarily smoothly continuous.
Two peaks may occur in the graphs for some of the
predictions. The primary peak (near field or nearest the
source) may occur because: the plume is initially dense; or
the release is near the ground and horizontal. The
secondary (furthest downwind) peak may occur because the
plume reached its final rise height (buoyant plumes) and
dispersion conditions result such that the ground level
concentrations are increasing from the lofted plume.
Secondary peaks flagged by ERCBH2S program must
be carefully considered by the planner.
7 Output Pages
115
7 Output Pages
116
8.
Batch Page
Introduction
ERCBH2S has a batch processing feature to accommodate calculation of the ERP
zones in sequence for several facilities without user intervention. It functions like
a database wherein each row of data is an input/output record (row in spreadsheet)
and each column is an input/output field (variable on inputs page).
The batch processing database (input/output list) is found on the BATCH page.
Variables on the BATCH page are arranged (horizontally) – in a similar order to
those found on the INPUT page (arranged vertically – column C).
A new input group (Batch Control) appears at the front of the input fields to
control BATCH operations. Two other new groups appear at the end of the input
fields - one for calculating ERP zones for gas and liquid gathering systems (see
‘Performing a Gas Pipeline Network Analysis – Tutorial’ on page 141), and the
other to record ERCBH2S calculation outputs. BATCH processing groups are
listed below.
GROUP
DESCRIPTION
Batch Control
Integer variables to control the operation of the batch
process
Administrative
Information about the applicant and the location
under study
Calculation Controls
Pipeline Details
Well Details
Selection of the Flavour for the template, analysis
type and scenario name.
If the Flavour is GAS PIPELINE, physical
characteristics of the gas pipeline are specified.
If the Flavour is GAS WELL, physical
characteristics of the gas well are specified.
Liquid Details
If the Flavour is LIQUID PIPELINE/WELL,
physical characteristics of the oil/produced water
pipeline/well are specified.
Sour Gas Composition
The chemical composition of the gas released is
specified.
Advanced User Selected
Case
8 Batch Page
This section allows advanced users to control
calculations for selected meteorological conditions
117
and pipeline release hole fraction rather than the
complete screening matrix.
Gas Gathering System
Pipeline Networking
Input variables and calculations for pipeline networks
(see Chapter 9 - Pipeline Gathering Systems)
Liquid Gathering System
Pipeline Networking
Input variables and calculations for pipeline networks
(see Chapter 9 - Pipeline Gathering Systems)
Output
Calculation predictions of the ERP zones from the
HAZARD DISTANCES page are recorded.
Working with the BATCH Page –
Summary Overview
Data Entry
Data Entry (and data removal) is discussed in more detail further on.
Data may be entered directly into the BATCH page, or data may be entered on
the INPUT page and saved to the BATCH page using the SAVE TO BATCH
command on the ERCBH2S menu or button-bar,
. Similarly, the user can
select a row on the BATCH page and copy the input fields to the INPUT page
using the READ command,
. The user can also scroll through BATCH
records FROM the INPUTS page by using the FIRST
NEXT
or LAST
, PREVIOUS
,
commands.
The user may enter numeric values, text or functions for any of the input fields.
This allows the ERCBH2S program to be linked to user specific databases or
calculation spreadsheets. Deleting or moving columns (fields) and re-formatting
is not permitted.
The BATCH page may contain any mixture of Sour Operations Types (Gas
Pipeline, Gas Well or Liquid Pipeline/Well), or pipeline gathering system records.
Calculating Emergency Response and Planning
Zones
Similar to pressing the CALCULATE EPZ command,
is the Batch Calculate EPZ,
8 Batch Page
, the batch equivalent
. Batch Calculate EPZ steps through
118
the entire batch page database of input records, loads each record to the INPUTS
page, executes the CALCULATE EPZ command, and then copies the
calculation results (along with any error codes) back to the ‘Output’ section of the
BATCH record/row.
Because the calculations can be time consuming, the user is prompted “Are you
sure you want to run this ...” before starting the assessment. The user may turn
off this prompt by toggling the SILENT START option from the menu-bar
ERCBH2S→Setup→Silent Start. A progress meter displays the progress of
the BATCH operation calculations. Pressing the CANCEL button on the dialog
or the ESC keyboard button will terminate the batch analysis.
Batch Page / Inputs Page Relationship
General
Before using the batch processing feature, it is vital that the user understand the
relationship between the INPUTS page and the BATCH page.
The INPUTS page is never erased. It always displays whatever data was LAST
entered to it.
ƒ
If the last ERCBH2S action was Calculate EPZ, the INPUTS page
displays the inputs that coordinate with calculation results displayed on the
ERP SUMMARY page.
ƒ
If the last ERCBH2S action was BATCH Calculate EPZ, the INPUTS
page displays the last BATCH record ‘run’ by ERCBH2S.
ƒ
If the last action involved user entries directly to the INPUTS page, then
that page is displayed.
ƒ
If the last action was transferring a BATCH record to the INPUTS page,
then that BATCH record is displayed.
Input Data Connection Between the Pages
For user inputs, data entry is not linked between the INPUTS page and the
BATCH page. While data can be moved from one page to the other, changes to
one page do not affect the other page, even if the scenario names match.
8 Batch Page
119
The following commands move data between the BATCH and INPUTS pages:
.
The READ command
Fetch the FIRST record to the INPUTS page
Fetch the PREVIOUS record to the INPUTS page.
Fetch the NEXT record to the INPUTS page
Fetch the LAST record to the INPUTS page
Save INPUTS to the BATCH page
Input data on the BATCH page is only
changed by either ‘over-writing’ an existing
scenario on the BATCH page with a new
INPUTS page (same scenario name), or by
directly making the data change on the
BATCH page. For any given scenario, there is
no user-input ‘live/active link’ between the
BATCH and INPUTS page.
Calculation Results (Outputs) Data Connection
Between the Pages
From INPUTS to BATCH
When using the ‘Save INPUTS to the BATCH page’ command
, calculation
results (outputs) ALWAYS go too - even if the calculation results do not match
the inputs. Therefore use caution when activating this command. If saving a
completed ‘run’ scenario (has no red flag banner across the top of the INPUTS
page), this is an appropriate command to use.
When saving an input scenario that hasn’t been ‘run’ yet (has a red flag banner
across the top of the INPUTS page), first activate the ‘erase all output fields’
button to re-set calculation results to ‘0’ before moving the INPUTS to the
BATCH page. To store valid results, you must activate the CALCULATE EPZ
, wait until calculations have been completed, and then move the
command
scenario to the BATCH page.
8 Batch Page
120
The ‘Erase all output fields’ button
does not erase
calculation results stored on the BATCH page – it erases
them from the other ERCBH2S pages.
When the ‘erase all output fields’
command is activated, a red flag banner
appears at the top of the INPUTS page, cautioning the user that calculation
results do not match user inputs. This is because calculation results now show ‘0’
distances.
,a prompt will
When using the ‘Save INPUTS to the BATCH page’ button
appear if the scenario name on the INPUTS page matches a scenario name
already recorded on the BATCH page.
STOP AND THINK – do you want to completely overwrite this particular record
on the BATCH page with this new data ‘set’ (Input AND Calculation Results)?
Remember that if there is output data stored on the BATCH page for this
particular scenario, it will be over-written with whatever calculation results
(outputs) are currently displayed on the other Excel pages.
From BATCH to INPUTS
The following commands will move a record (row) from the BATCH page to the
INPUTS page:
The READ command (done from the BATCH page).
Fetch the FIRST record to the INPUTS page (done
from the INPUTS page).
8 Batch Page
121
Fetch the PREVIOUS record to the INPUTS page
(done from the INPUTS page).
Fetch the NEXT record to the INPUTS page (done
from the INPUTS page).
Fetch the LAST record to the INPUTS page (done
from the INPUTS page).
When a record or row is brought from the BATCH page to the INPUTS page,
only the inputs are copied – not the calculation results (outputs). The only way to
change calculation results shown at the bottom of the ERP SUMMARY page is
to activate a program ‘run’ command such as CALCULATE EPZ or BATCH
CALCULATE EPZ.
When copying an INPUTS page to a BATCH
page, ALL calculation results (OUTPUTS) are
appended/copied to the BATCH row/record for
the particular scenario identified.
However, when copying/reading/fetching a
BATCH record/row to the INPUTS page,
only the BATCH input records are copied over.
Any associated calculation results for the
BATCH row/record are not brought along.
Entering Data to the Batch Page
The ‘safest’ way to enter data to the BATCH page is to use the INPUT page as
the user interface. Enter data to the input fields the same way as for a standard
analysis. Particular attention should be directed towards the SCENARIO
NAME, since the batch processing uses this field as the unique row identifier.
That is, each record in the batch processing database must have a different
(unique) SCENARIO NAME. By using the INPUTS page to enter data for
each scenario – standard error checking, orange warnings, orange resets and
general comments appear to help the user correct invalid entries. These features
do not appear on the BATCH page.
8 Batch Page
122
Red flag warning banners, orange warnings and orange
resets related to user inputs do not appear on the
BATCH page.
Once the INPUTS page entries have been completed, the data may be saved to
the BATCH page using the SAVE TO BATCH command
. The SAVE TO
BATCH button is only visible when the INPUT page is active, preventing
accidental saves.
If the INPUTS page data is saved to the BATCH page and the
SCENARIO NAME already exists, the user is prompted to accept the save
operation or to cancel.
•
If the user cancels the operation, then the SCENARIO NAME should
be changed to a unique name and the operation attempted again.
•
If the user accepts the save operation, then the record on the BATCH
page with the same SCENARIO NAME is COMPLELETY
overwritten with new data from the INPUTS page – along with all
calculation results (outputs) that appear on the other Excel pages.
Therefore any existing calculation results on the BATCH page (with
the same SCENARIO NAME) are erased and replaced.
Copying, Deleting, and Editing Rows of Data on the
BATCH Page
Once data has been saved to the BATCH page, the user may make changes to the
data by editing the variables directly on the BATCH page. This is particularly
useful for sensitivity or uncertainty testing of input variables.
8 Batch Page
123
To perform a sensitivity test, records (rows) on the BATCH page can be
duplicated several times (use the Excel copy and paste functions) and the test
variable can be changed for each copy to perform the test. Remember to change
the SCENARIO NAME for each duplicate copy. If the scenario is for a pipeline
AND the ‘Pipeline Gathering System’ portion of the BATCH page has been used
(see Pipeline Gathering Systems in Chapter 9), do not copy the row/scenario any
further than column CN.
Be extra careful when copying or duplicating rows. For
instance, the Excel auto-fill button and mouse drag can
create errors in the input file by auto-incrementing numeric
fields
Use caution when copying rows on the BATCH page –
you may end up copying calculation results you don’t want,
and/or gathering system details (segments and nodes).
If you chose to copy the OUTPUT results from the original scenario and apply
them to the new scenarios (unless the output results are zeros), the safest option is
to simply delete the results for the new rows/scenarios (OUTPUTS group on the
BATCH page - beginning at column DO). Otherwise, future input changes to the
new rows will appear to coordinate with ‘old’ calculation results. Eventually the
new inputs will be used for new calculations, but until then - it is better not to list
‘false’ results.
Deleting Rows of Data
To delete a row of data on the BATCH page, left ‘click’ on the row number you
wish to remove, then ‘right click’ and select ‘clear contents’. To move other rows
of data ‘up’ to fill in empty spaces on the BATCH page (not required), use the
Excel cut and paste functions.
Empty data rows in between rows of data on the BATCH page are acceptable, but
the user must remember to label these rows with a “0” in column A. Otherwise,
when the BATCH CALCULATE EPZ process identifies rows on the BATCH
page that require processing, it will stop when it comes to a blank in this column,
and assume there is no further data on the BATCH page. Blank data rows (other
than at the end of a spreadsheet) must not be left in when creating an ERCBH2S
export file. Other rows of data must be moved up to fill in blank rows (use the
Excel cut and paste features).
8 Batch Page
124
Checking for Red Flag and Other Warnings
Red flags, orange warnings, orange resets and other comments are visible on
the INPUTS page and are not shown on the BATCH page. Further, orange flags
for entries that have been reset by ERCBH2S (column E on the INPUTS page)
cannot be seen on the BATCH page. To view these important warnings, a
BATCH row/scenario must be brought to the INPUTS page.
red flag warning banners, orange warnings and orange
resets related to user inputs do not appear on the
BATCH page.
When ERCBH2S assigns a different value to a user entry
(an ‘orange reset’), the ‘reset’ value does not appear on
the BATCH page. The only way to see an orange reset
for a BATCH page scenario/record is to view the record
on the INPUTS page.
Unless a user is well experienced with ERCBH2S inputs, it is recommended to use
these user input error checking features on the INPUTS page by viewing each
BATCH record before activating
(Batch Calculate EPZ). This helps
avoid most calculation error messages.
Red flags, orange warnings and orange resets are described in more detail in
Chapter 5 under Red Flags and other Warnings.
To view a BATCH scenario on the INPUTS page
•
From the BATCH page, input fields on the BATCH page can be copied
to the INPUT page using the READ command,
. The READ
command is only visible while the BATCH page is the active page, to
prevent copying data unknown records from the BATCH page. The
active row on the BATCH page is copied with the READ command. The
active row is the row with the cursor, the highlighted row or the row
selected with the mouse.
•
From the INPUTS page, the user can scroll through BATCH records
using the FIRST
, PREVIOUS
, NEXT
or LAST
commands. These commands use the SCENARIO NAME for each
record and look for the record before or the record after the scenario name
listed on the INPUTS page.
8 Batch Page
125
Batch operations work on all fields on the BATCH page.
This means that if some of the records are not visible
because of the AutoFilter settings, the records will still be
evaluated in the batch operation depending on the Batch
Control setting for each record.
Batch Control Group
Run or Not Run
The RUN or NOT RUN field is used to include or exclude the record (row) from
the Batch Operation. The setting is either “0” (do not include this record in the
Batch operation) or “1” (include this record in the Batch operation).
If there are any blank rows in between rows of data on the BATCH page, they
must be labelled with a “0” in this column. Otherwise, when the BATCH
CALCULATE EPZ process identifies rows on the BATCH page that require
processing, it will stop when it comes to a blank in this column, and assume there
is no further data on the BATCH page.
Print/Save
The Print/Save field is used to perform operations between Batch Calculation
Operations. It tells ERCBH2S what to do while a BATCH Calculate EPZ (or
other BATCH run function) is operating. The command entered will perform at
the end of each row/scenario execution.
The field entry is cumulative and is described in the table below.
1
Print ERP Summary Pages to the default printer after each
Batch Operation
2
Save the entire spreadsheet after the Batch Operation
3 (=1+2)
By summing the values, a combination of the commands is
performed, e.g., a field entry of 3 performs both print and a
save after the record has been evaluated.
The file save operation is useful for large assessments with many rows in the
database. Making use of frequent file saves ensures that the results of the
8 Batch Page
126
computations are backed up in the unfortunate event of a computer malfunction
during subsequent computations. It is not necessary to save the results after the
analysis for each record (it slows down the process), but perhaps after every tenth
analysis. If one of the records is marked to be saved for a batch operation, then
during the initialization phase of the batch command, a save operation is
immediately performed. This ensures the save operations perform effectively
before the user leaves during the batch process.
When performing batch operations, save your work before
you start the time consuming runs, and include the save
command (2, in Column B) occasionally.
Batch Operations
Check for Scenario Duplicates
Duplicate scenario names can lead to confusion when interpreting the results.
Before performing any batch program ‘run’ command, it is recommended that
you first use the ‘Check for Scenario Duplicates’ menu item as shown below.
8 Batch Page
127
If scenarios were saved to the BATCH page from the INPUTS page, a scenario
duplication check was already preformed. If scenarios were created directly on
the BATCH page (especially when using Excel’s copy and paste functions), then
no scenario duplication check will have been performed by the program.
Batch Run ERCBSLAB
The Batch Run ERCBSLAB command,
, runs the ERCBSLAB calculation
for each record in the batch processing list. The ERCBSLAB program is run for
the single meteorological wind speed and atmospheric stability class entered in
the User Selected Case input fields or the ERCB default values. Calculation
results using this feature are not acceptable for ERCB submission.
Because the single meteorological case calculation is considerably faster than the
screening matrix calculations, this command is useful for sensitivity testing of
input variables or for testing inputs for large databases. For testing purposes,
once the Batch Run ERCBSLAB command has been completed, the error
messages can be reviewed to check for issues with inputs to the model.
Batch Calculate EPZ
The Batch Calculate EPZ command,
, executes the complete set of 54meteorological cases in the screening matrix calculation for each record in the
database. For pipelines, the screening matrix calculation also includes 11-Ae/Ap
exit hole assessments and ESD timing calculations. The ignited release
calculations are also performed.
The Batch Calculate EPZ command calculations are extensive and may take
some time to complete, especially for large databases. It is recommended that
assessments for large databases be assessed in smaller sets (such as several
hundreds of records) and or in combination with the use of the PRINT/SAVE
settings. It is not necessary to divide the assessment into different spreadsheets.
To assist the user in avoiding excuses, save your work!
8 Batch Page
128
Batch Output Group
Errors
Error message dialogs are suppressed during batch operations, and instead, errors
are recorded in the ERROR output column on the BATCH page (column DO).
The error output column is illustrated below.
Errors codes below 1000 are listed as a cumulative index as described in the
ERROR CODES page of ERCBH2S and summarized in the following table.
Therefore, an error index of 7 means that ERCBFLASH (code=1), ERCBSLAB
(code=2) and MetMatrix (code=4) were not executed successfully. Error codes
starting at 5000 are for ERCBSLAB. Error codes starting at 9000 are for
ERCBFLASH.
8 Batch Page
129
ERROR CODE
1
2
4
16
32
64
1000+
DESCRIPTION
ERCBFlash failed to complete successfully
ERCBSLAB failed to complete successfully
MetMatrix failed to complete successfully
AeAp Iteration failed to complete successfully
Calculation process was cancelled by user or system
interruption
ERCBH2S was run in a nonregulatory mode
Other Fatal Error; see ERROR CODES PAGE in
ERCBH2S
Output Data Fields
The output data fields are the same as the HAZARD DISTANCES page. Refer
to Chapter 6 – Calculation Pages under ‘Erasing Calculation Results’.
Calculation results (outputs) on the ERP SUMMARY page can be erased by
selecting ‘Erase all output fields’ from the technical sub-menu as shown below or
by selecting the ‘Erase all output fields’ button
from the button bar. This
command also erases output from other ERCBH2S ‘Summary/Graphics’ pages,
but does not erase outputs stored on the BATCH page.
Saving a Batch Page as an Excel File
Saving ERCBH2S scenarios as Excel files is described in Chapter 3 under Saving
Scenarios as Excel Files.
8 Batch Page
130
It is strongly recommended that you
save your work!
Creating a Batch Export File for ERCB
Submission
The input and key ERP output data stored on the BATCH page can be exported
to an ERCBH2S batch export file for convenient email transfer or backup.
From the menu-bar, ERCBH2S→Technical→ Batch Export... prompts the
user using common windows file dialog wind for a folder and a file name. For
ERCB submission, licensees/applicants are required to use the following file
naming protocol:
BA code - ERP Plan Ref# - Date (DD/MMM/YY)
For example, if a company with the BA code of WXYZ submits a file on July 5th,
2008, the file would be named:
WXYZ-1234-05Jul08.csv
The .csv file extension - ‘comma separated variable - is automatically attached to
the file name. The variable names are those expected by ERCBH2S to match the
INPUTS page - the order of the variables in the file is not important.
The export file can be viewed using Excel or Notepad or other text editor.
An ERCBH2S batch export file can be reloaded to a BATCH page using the
batch-import function ERCBH2S→Technical→Batch Import... from the
menu bar.
8 Batch Page
131
The .csv file does not contain user information added to the NOTES page.
BATCH page submissions to the
ERCB must not have any error
codes in column DO!
Batch Page Tutorial
Part of the Gas Well Tutorial in Chapter 10 (beginning at step 11) describes how
to work with the BATCH page.
8 Batch Page
132
9.
Pipeline Gathering Systems
Overview
The ERCBH2S Gas 1 Gathering System analysis feature calculates the Equivalent
Segment Length for sour gas, acid gas and oil effluent pipelines with a
GLR>1000. The equivalent length is used to determine both the ERP zones using
gas pipeline calculations, and ERCB Sour Gas Level Designation.
The ERCBH2S Liquid 2 Gathering System analysis feature calculates the
Equivalent Segment Length for oil effluent pipelines with a GLR ≤ 1000. The
equivalent length is used only to determine an ERCB Sour Gas Level
Designation, and is not used to determine the ERP zones using liquid pipeline
calculations. Currently, the only liquid pipeline substance with potential to have
an ERCB Sour Gas Level Designation is oil effluent.
ERCBH2S calculates emergency response and planning zones for individual gas
pipeline segments, assuming there is an Emergency Shut Dow (ESD) valve at
each end. Calculations also assume that the only source of gas (or other material)
available for release is contained within the described segment plus whatever
additional material can be provided from each end - upstream and downstream,
before the ESD valves close 3 .
Real pipeline gathering systems frequently do not fit this description because
there are pipeline tie-ins in-between pipeline ‘from’ and ‘to’ locations – tie-ins
that may not have a flow control device to prevent product flow into the modelled
pipeline segment.
Liquid pipelines with a GLR > 1000 are modelled in the Gas Pipeline group. The User is
directed there automatically on the ERCBH2S INPUTS page when the pipeline substance is
selected.
2
Liquid pipelines with a GLR ≤ 1000 are modelled in the Liquid Pipeline group. The User is
directed there automatically on the ERCBH2S INPUTS page when the pipeline substance is
selected.
3 Additional flow to the segment is determined by ERCBH2S (during Calculate EPZ
calculations) based on expected MOP and H2S, and the ESD closure time setting specified by
the user on the INPUTS page. The ESD closure setting must represent the SLOWEST
valve closure setting. If there is even one no flow control node, ERCB SOURCE
MITIGATION default valve settings must not be over-ridden by user inputs unless the
licensee has pre-planned actions to ignite, draw-down or otherwise stop the flow of H2S to
atmosphere. ERCBH2S default SOURCE MITIGATION settings provide no effective
ESD valve closure.
1
9 Pipeline Gathering Systems
133
To allow for this additional source of material, ERCBH2S inputs for gas or liquid
pipelines require either:
1.
Equivalent Segment Length (between ESDs),
OR
2.
Equivalent Cumulative Pipeline Volume (between ESDs)
These entries account for the total mass of H2S (based on licensed levels) in a
pipeline segment PLUS segments upstream and downstream, to points where flow
control devices that can prevent additional flow to the modelled segment are
encountered, or the pipeline start or end is encountered (e.g., well, plant, battery,
etc.). When the user supplies one of these two entries, ERCBH2S calculates the
other value. Therefore, only one of the entries is needed.
This approach (total mass of H2S based on licensed levels) is consistent with the
previous ERCB approach of cumulative H2S release volumes for pipelines.
A gas pipeline gathering system segment has an equivalent
cumulative pipeline length determined by the total mass of
H2S (based on licensed levels) in the segment and in
segments upstream or downstream, to points where flow
control devices that can prevent additional flow to the
modelled segment are encountered, or the pipeline limit is
encountered (e.g., well, plant, battery, etc.).
The release from a segment is modelled using the gas
characteristics of the segment, not the average of adjoining
segments.
The chemical and physical properties used in the ERCBH2S analysis for ERP
zone determination are the specific values entered for the modelled segment.
These are reasonable estimates for the screening level analysis given that the ERP
zones are dependent on the high initial flow rates form the rupture.
Equivalent Segment Length (between ESDs)
Equivalent Segment Length is easily calculated IF the interconnecting pipelines
(followed ALL THE WAY back to points where flow control devices that can
prevent additional flow to the modelled segment are encountered, or the pipeline
limit is encountered, e.g., well, plant, battery, etc.), have precisely the same
qualities as the pipeline being modelled (inside diameter, licensed pressure, and
9 Pipeline Gathering Systems
134
licensed H2S %). In these cases, segment lengths can just be summed to arrive at
the Equivalent Length entry for ERCBH2S.
When any pertinent, interconnecting pipeline has one or more different qualities
(as already described), equivalent length calculations are much more complicated.
For these cases, the user may choose to either supply the alternate entry
(Equivalent Cumulative Pipeline Volume), or use the ‘Gathering System Analysis
Feature’ provided on the ERCBH2S BATCH page (described later in this chapter)
to calculate the equivalent segment length. The Gathering System Analysis
feature is essentially a calculator used to arrive at an equivalent segment length,
and it must be used BEFORE ERCBH2S dispersion modelling (Calculate EPZ) is
performed.
If a gathering system is described on the Gathering System Analysis portion of
the ERCBH2S BATCH page, and one or more portions of the system have
Equivalent Segment Lengths ‘manually’ calculated, refer to the next section in
this chapter for important details.
Illustrations 1 and 2 in this chapter (to follow) further describe why pipeline H2S
volumes must sometimes be cumulative.
Equivalent Cumulative Pipeline Volume (between
ESDs)
Similar to Equivalent Segment Length between ESDs, the Equivalent Cumulative
Pipeline Volume accounts for a volume of the modelled segment PLUS additional
‘volumes’ available to the segment from upstream and downstream, to points
where flow control devices that can prevent additional flow to the modelled
segment are encountered, or the pipeline limit is encountered (e.g., well, plant,
battery, etc.).
Performing the calculations needed for this entry is sometimes preferable to using
the ‘Gathering System Analysis Feature’ provided on the ERCBH2S BATCH
page (described later in this chapter).
The formula for this calculation is provided in the ERCBH2S Technical Reference
Document in section 5.4. Note that if the licensed maximum operating pressure,
minimum operating temperature and licensed maximum H2S concentration is the
same for all segments, the calculation is the straightforward sum of segment
lengths ‘times’ the pipe area.
9 Pipeline Gathering Systems
135
Equivalent Cumulative Pipeline Volume may be entered as
an input to ERCBH2S instead of Equivalent Segment
Length.
Equivalent Cumulative Pipeline Volume calculations are
performed manually by the user according to the formula
described in the ERCBH2S Technical Reference document,
section 5.4.
This method may be preferred for gathering systems with
multiple, complex interconnections that are cumbersome to
describe on the BATCH page for the ERCBH2S Gathering
System Analysis feature.
This method must be used for any portions of a gathering
system that have more than one outlet (e.g., a lateral used
occasionally to divert pipeline flow).
Gathering System Analysis
To use the ERCBH2S Gathering System Analysis feature, a simple schematic of
the gathering system should be prepared. The schematic assists the user in
creating a labelling scheme based on nodes and pipeline segments. The labels are
listed in a summary table that provides the user with entries required for the
ERCBH2S Gathering System Analysis feature on the BATCH page. The labels,
numbering scheme and summary tables are described later in this chapter under
Gas Gathering System Analysis - Tutorial.
Preliminary discussions (based on two example illustrations that follow) reference
the following terms. These terms are used throughout this chapter and in other
sections of the ERCBH2S User Guide.
NODE
•
The start of a modelled pipeline segment or sub-segment (from
location)
•
The end of a modelled pipeline segment or sub-segment (to location)
•
An ESD valve
•
A back-flow check valve (CV)
9 Pipeline Gathering Systems
136
•
A tie in with another pipeline
•
A change in pipeline modelling conditions such as pressure, H2S
concentration, outside diameter, wall thickness, or temperature.
PIPELINE SEGMENT
•
Has ONLY one node at each end.
•
Does not have nodes between the beginning and ending nodes.
A pipeline segment length is entered as the distance between nodes. If using the
Gathering System Analysis portion of the BATCH page, the equivalent segment
length is left blank for now.
The following two illustrations and discussions are provided only to explain why
some H2S volumes must be ‘summed’ before performing ERCBH2S dispersion
modelling. They are presented here only as background for subsequent
discussions, and require no action by the user.
Example Illustration 1 (Single Segment)
Two pipeline segments shown in the following diagram are defined by a start
node tag “1” and terminated with an end node tag “2”. The top segment starts
with an open flow condition at node-1 and ends with an ESD valve at node-2. In
the event of a rupture of this pipeline segment (between nodes-1 and-2), gas could
flow continuously from beyond node-1 (upstream) into the segment, and could
‘back-flow’ for some time from beyond node-2 (downstream) into the segment
until the ESD valve detects a pressure sufficient to close the valve and stop the
flow (or until the valve is manually closed).
The second pipeline segment in the preceding diagram (the lower line) also begins
with an open flow condition at node-1, but ends with a ‘back-flow check valve’ at
node-2. In the event of a rupture of this pipeline segment (between nodes-1 and2), whereas gas could flow continuously from beyond node-1 (upstream) into the
segment, back-flow from beyond node-2 is prevented by the check valve. In
ERCBH2S, check valves are assumed to function (perfectly and immediately)
when a downstream flow reversal is detected.
9 Pipeline Gathering Systems
137
Illustration 1 - Summary Discussion
When pipeline segments are connected, a pipeline network analysis is used to
estimate the amount of material that could be released. The analysis of high
pressure blow-down in pipeline networks is complex, and the analysis used in
ERCBH2S is a simplification using ‘ideal gas’ properties to determine the
approximate combined volumes in pipeline networks. The ‘ideal gas’ model
provides an estimate of the total volume available for release by assuming
adjacent segments have similar compressibility. The ERP zone calculations for
the release modelled in ERCBH2S for each segment uses ‘real gas’ properties.
Summary discussions continue following Illustration 2.
A gas pipeline gathering system analysis assumes that each
segment has similar compressibility. If the compressibility
significantly changes within the gathering system, the
system should be divided into separate analyses ‘groups’.
Example Illustration 2 (Connecting Segments)
Now consider the simple joining of two pipelines as shown in the following
diagram. The example shows ESD valves at nodes 1, 3 and 4. The two pipelines
are joined at node 2 – where there is no flow control device. If a rupture occurred
in segment N1-N2 (node 1 to node 2), material could escape through the rupture
from upstream of the segment (node 1) until it closed. Because there is no flow
control device at node 2, material could ‘back-flow’ from both downstream
segments (N2-N3 and N4-N3). These segments would provide material to the
emission scenario until the respective ESD valves closed, (nodes 3 and 4).
The ‘Equivalent Segment Length between ESDs’ used by ERCBH2S, is
determined by
1.
summing the material/product that could escape between flowcontrol devices (or the physical limits of the pipeline), and
9 Pipeline Gathering Systems
138
2.
using the total/cumulative volume calculation to re-calculate
individual segment lengths (node to node), based on the
characteristics of the individual segments.
When the pipeline dimensions and gas compositions are the same for all
segments, equivalent segment lengths can be readily determined by summing
segment lengths. However, for real pipeline networks, pipeline dimensions
change as well as gas compositions and pressure levels. Therefore, the mass of
material escaping must be accounted for from each segment.
The ERCBH2S Gathering System Analysis feature on the BATCH page is
designed for these calculations by acting as a ‘calculator’; summing H2S
volumes from interconnecting segments according to the segments and
nodes described to it by the user. This ‘user directed’ action is done
BEFORE ERCBH2S dispersion modelling (Calculate EPZ) is performed.
If there were a pipeline failure in segment N1 – N2:
•
Segment N1-N2 would have the total mass of H2S determined for
segments N1-N2, N2-N3, and N4-N2. Subsequently
•
the Equivalent Segment Length between ESD valves is determined
using the total mass of H2S, and the pressure, diameter and gas
composition for segment N1-N2 that equates to the total H2S mass.
ERP zones for pipeline segment N1-N2 must therefore based upon an ERCBH2S
analysis using the characteristics of segment N1-N2, but with an Equivalent
Segment Length determined by the total mass of H2S from adjoining segments.
Again, the ERCBH2S Gathering System Analysis feature on the BATCH
page is designed to automatically perform these calculations, and can be
utilized by properly describing the gathering system in terms of
‘segments’ and ‘nodes’ as described in the tutorial later in this chapter.
Similarly, for a failure in segment N4–N2, the total mass of H2S is the same as
already determined for segment N1-N2’s calculation (previous), but the
Equivalent Segment Length is determined using the pressure, diameter and gas
composition for segment N4-N2 that equates to the total H2S mass that could
potentially escape. ERP zones for this pipeline segment are therefore, based upon
the characteristics of segment, but with an Equivalent Segment Length
determined by the total mass of H2S from adjoining segments.
9 Pipeline Gathering Systems
139
Illustration 2 – Summary Discussion
The network model used in ERCBH2S uses an ideal gas assumption to determine
the total mass of H2S within the segment group bounded by flow control valves or
the pipeline physical limits (e.g., well, plant, battery, etc).
Conclusion
The ERCBH2S Gathering System Analysis feature (on the BATCH page)
determines Equivalent Segment Lengths for each individual segment described to
it, using the gas composition and described pipeline characteristics for the
individual segment. In order to get reliable calculation results, users must
carefully follow the directions provided in this chapter of the ERCBH2S User
Guide when describing a gathering system on the ERCBH2S BATCH page.
The Gathering System Analysis feature is essentially a
calculator used to arrive at an Equivalent Segment Length
BEFORE ERCBH2S dispersion modelling (Calculate EPZ)
is performed.
‘Node descriptions’ provided in the ‘gathering system
analysis’ section of the BATCH page are not referenced in
ERCBH2S dispersion modelling. They are used only to
identify when pipeline H2S mass should (and should not) be
summed together. This is done by logic built into the
spreadsheet - activated by the user as described in the
tutorial later in this chapter.
A pipeline gathering system segment has an Equivalent
Segment Length determined by the total mass of H2S in the
segment and in segments upstream or downstream (based
on licensed levels), to points where flow control devices
that can prevent additional flow to the modelled segment are
encountered, or the pipeline limit is encountered (e.g., well,
plant, battery, etc.).
The release from a segment is modelled using the gas
characteristics of the segment. Modelling (e.g.,
Calculate EPZ) is based on expected maximum
MOP and H2S.
The amount of material available for release from a particular segment is
therefore a function of the joined segments and their flow controls at the nodes.
The simplified total Equivalent Segment Length is modelled in ERCBH2S. The
chemical and physical properties used in the ERCBH2S analysis for the
determination of the ERP zones are based on the specific values entered for the
segment. These are reasonable estimates for the screening level analysis given
that the ERP zones are dependent on the high initial flow rates from a failure.
9 Pipeline Gathering Systems
140
Gas Gathering System Analysis – Tutorial
Introduction
To work through this tutorial, in addition to the terms ‘Node’ and ‘Pipeline
Segment’, the following terms are used:
NODE LABEL
Each Node Number has only one Node Label. Node Label and Node Position
(identified by the BATCH column the Node Number is entered in – either
upstream or downstream) are essential for ERCBH2S ‘total H2S-mass’
calculations, and subsequent Equivalent Segment Length calculations.
Label choices are:
ESD
Emergency Shut-down Valve
CV
Back-flow check valve
- -4
Open flow- no flow control
NODE NUMBER
Unique
A node number is unique. It identifies a physical place and has a specific
characteristic (the Node Label). As long as a pipeline segment is physically
connected to a particular Node, the Node Number can be re-referenced. It can be
referenced as many times as there are pipeline segments physically connected to
it.
Numbering Protocol
Because Node Numbers may become part of the Pipeline Segment Label, users
may wish to keep Node Numbers brief; e.g. N1, N2, N3 and so on. However,
4
ERCBH2S ‘Equivalent Segment Length’ calculations ‘look’ for ESD or CV when determining
what H2S masses to sum together. If ANYTHING else is entered, the calculations consider it an
‘open flow’. Therefore it is acceptable to label, for example, a manual valve as ‘MAN’. For
‘summing’ calculation purposes, ERCBH2S considers this an ‘open flow’ since it is labeled
neither as ESD or CV. Manual valves are considered ‘open flow’ because they do not close
automatically.
9 Pipeline Gathering Systems
141
Node Numbering can follow any protocol chosen by the user. A suggested format
is an alpha character followed by a number. Some gathering systems may already
have an ESD, Back-flow Check-valve, tie-in numbering convention; e.g., ESD1,
ESD2, or CV15, CV16, or TY22, TY23, and so on. As long as the number is
UNIQUE - only references one exact location with one exact characteristic (the
Node Label), anything can be chosen.
Sequential or Out-of-Order?
While it is recommended that Node Numbers generally increase in the direction
of flow, it is not essential. If new tie-ins occur, or if additional flow controls are
installed thereby creating a ‘new Node’ amongst ‘existing Nodes’, the existing
Node Numbering does not have to be changed as long as the new Node is given a
unique Node Number, and the BATCH gathering system descriptions of pipeline
segments connected to/interrupted by the new Node are changed accordingly.
Multiple Analyses on a BATCH page
There can be multiple gathering system analyses on a BATCH page provided
Node Numbers are not re-used to label different locations.
Ambiguous Nodes
Re-using a Node Number for a ‘new’ physical location, or assigning ambiguous
Node Labels to a Node Number on the same BATCH page can cause circular
references and/or calculation errors. Subsequent equivalent segment length
calculations will either fail or the results may be unreliable.
Other Licensee Tie-ins
If material can be contributed to the user’s pipeline from another licensee’s
pipeline (e.g. not connected at a flow control device that prevents flow into the
user’s pipeline), additional material must be accounted for when determining
Equivalent Segment Length or Equivalent Cumulative Pipeline Volume. For
pipelines such as these, the user must
1.
Perform a manual calculation for any of the user’s pipelines to which it
is applicable (see Formulae for Pipeline Networks), or
2.
Use the Gathering System Analysis portion of an ERCBH2S BATCH
page to arrive at the Equivalent Segment Length, and then manually
enter this number for any of the user’s pipelines to which it is
applicable. When doing this, use a separate BATCH page as you will
need to include details of the other licensee’s pipeline(s). This page
does not need to be submitted to the ERCB, you are only using it to
arrive at the Equivalent Segment Length for your pipeline(s). See
‘Tutorial Variation 2’ later in this chapter.
9 Pipeline Gathering Systems
142
To do this, the other licensee must be contacted regarding the location and type of
flow control devices and other licensing details (to enable calculations). Both
licensees must consider this material contribution to their respective gathering
systems.
NODE POSITION
A Node is either at the upstream end of a pipeline segment or sub-segment
(segment from location), or the downstream end (segment to location). This is
described to ERCBH2S by whatever BATCH column the Node Number is
entered to.
PIPELINE SEGMENT LABEL (SCENARIO NAME)
Pipeline Segment Labels allows users to identify gathering system segments as
modelled Node by Node on the ERCBH2S BATCH page.
For each segment, this label is entered as the Scenario Name (Administrative
details group on the INPUTS page, or column ‘L’ on the BATCH page). Each
label must be unique and should identify the segment according to the described
from location Node Number and to location Node Numbers; e.g., N1 – N2, or
N35 – N27, or ESD1 – CV 14, and so on. If the subject segment is ‘lease piping’,
modelled so that the gathering system continues to be ‘connected’ for purposes of
summing volumes, then the user should use slightly different scenario names.
Names such as ‘Lease Piping N3 – N4’ highlight that the modelled segment does
not have a pipeline line number or is not licensed by the ERCB. In these cases,
‘Lease Piping’ would also be entered for the pipeline line number. Even if the
pipeline is not licensed by the ERCB, it should be assigned the same pipeline
licence number as the connecting gathering system.
Tutorial
The same three-segment pipeline group shown in Example Illustration 2 is
used here to build an example gas gathering system analysis. The file
ERCBH2S-eg-Net1.xls contains these example calculations. This example is
for pipelines modelled as ‘Gas Pipelines’. There is a similar area on the BATCH
page for ‘Liquid Gathering Systems’ (columns DB – DN).
Before using the Gathering System Analysis calculation feature, users must first
fill out the pipeline details portion of the BATCH page, with the exception of
‘Equivalent Segment Length between ESDs’. For the following example, these
details have are filled out for you.
9 Pipeline Gathering Systems
143
1.
Step 1 – Table Preparation
Flow Schematic and Tables:
Describing a gathering system in
terms of Nodes and Pipeline Segments is easier with a schematic of the
system to be analyzed, clearly showing all of the ‘Node’ locations.
Using the schematic, carefully prepare a table listing each Node by Node
Number and Node Label. The Node Numbers should be added to the
schematic as illustrated in the following example.
NODE TABLE
Node Number
N1
N2
N3
N4
Node Label
(Flow Control)
ESD
-ESD
ESD
Finally, using the labelled schematic and the Node Table, the gathering
system can be described in a larger table, as shown in this example. This
table will be used for the inputs to the ERCBH2S BATCH page. Remember
to keep both tables and the schematic for future reference.
A user may wish to prepare a bigger table, with more references such as
pipeline licence number, and line number (or line number segment portion –
as per the Administrative group of the inputs), ‘from’ and ‘to location’, etc.
BATCH Page Input Table
BATCH
page
row
Scenario
Name
Column L
9 Pipeline Gathering Systems
Upstream
Node
Number
Downstrea
m Node
Number
Upstream
Node Label
(Valve Type)
Downstream
Node Label
(Valve Type)
144
number
Column
CO
Column
CP
Column
CQ
Column
CR
Row 11
N1-N2
N1
N2
ESD
--
Row 12
N2-N3
N2
N3
--
ESD
Row 13
N4-N2
N4
N2
ESD
--
Careful preparation of a Node Table, a BATCH Page Input
Table and a system schematic (complete with labels) will
help a user to avoid ambiguous Nodes.
Once labelled and described, it is a good idea to keep the
gathering system schematic and the tables for future
reference. They will be particularly useful if any of the
gathering system changes (new Nodes, changed Nodes,
etc.)
2.
On the BATCH page, scroll across to the Gas Gathering System-Pipeline
Networking input group (begins at column CO).
There are two parts to the input group which are colour coded white (user
input-column “CO to CR”) and orange (calculations column “CS to
DA”).
3.
Enter user input. When entering Node Labels, ERCBH2S requires exact
text for “ESD” and “CV” in order to perform calculations. The text string
for open flow or other can be any text the user selects, although two dashes
can easily alert the viewer to flow control ‘gaps’.
For each record in the pipeline gathering system database, enter
corresponding Node information as described in the table from Step 1.
Copy the formulas
The first record on the BATCH page (row 10 – orange-coloured cells in the
‘Gas Gathering System – Pipeline Networking’ group of the BATCH page)
contains formulae that must be copied/applied to the user’s pipeline
gathering system analysis rows.
Use the mouse to highlight range “CS10:DA10”. Right click and select
COPY. Then, using the mouse, left click and drag on the range of rows for
the analysis, e.g., CS11:CS13 (for this tutorial example). Right click and
select PASTE. ERCBH2S has just calculated ‘Equivalent Segment
Lengths’ for each pipeline segment included in this analysis group.
9 Pipeline Gathering Systems
145
The formulae can be copied to more rows for later use.
If you have rows of pipeline data for which you do NOT want
to calculate Equivalent Segment Lengths (because they
have manual calculations), copy the formulae with care.
Simply ‘dragging’ it may apply the formulae to rows of data
you are not including in the analysis.
4.
You Should See
After entering the data and pasting the formula (step 4), you should see
calculated Equivalent Segment Length Between ESD Valves, as
shown in the illustration below. Compare these values to the Segment
Length Between ESD Valves. Because of the pipeline networking,
the equivalent segment lengths can be much larger than the original
segment.
In the example below, the tutorial case gas composition was used with 10 %
H2S in segments N1-N2 and N2-N3, and a 20 % H2S used for segment N4N2 (licensed maximum H2S and pressure are used in the calculations).
9 Pipeline Gathering Systems
146
5.
Don’t forget to Link the results!
There is a formula that links the Gathering System Analysis Calculation
Result (the Equivalent Segment Length between ESDs) to the
input cell(s) ERCBH2S references for the ERP zone calculations (column
AF). The user must complete this step in order to have the ‘Effective
Segment Length’ in a place where ERCBH2S can find it when dispersion
modelling calculations are performed.
Left click on cell “AF10”, then right click and select COPY. Then, using
the mouse, left click and drag on the range of rows for the analysis
(AF11:AF13 for this tutorial example). Right click and select PASTE.
Use care when copying this action down the column, as it
causes entries in the column to be replaced with
coordinating entries from the Gathering System Analysis
portion of the BATCH page. Any rows of pipeline data
that have manual calculations should NOT be included in
the ‘dragging’ action. Instead, the formula should be
selectively ‘copied’ to the data rows it applies to. Applying it
to rows of data with Manual length calculations will result in
Equivalent Segment Lengths of 0 overwriting any lengths
manually entered.
The user must remember to complete this step in order for ERCBH2S to
reference the Equivalent Segment Length when the ERP zone calculations
are performed.
ERCBH2S ERP calculations do not use Equivalent Segment
Lengths unless the user has properly provided certain key
information and activated certain calculation sequences on
the BATCH page.
9 Pipeline Gathering Systems
147
The formula entered in field range AF: “Equivalent
Segment Length between ESD Valves” can be
overwritten if the user selects the SAVE TO BATCH
command from the INPUTS page (if the INPUTS page
has the same scenario name as the BATCH row!)
It is therefore important to remember to re-enter the formula
(column AF) if it has been over-written.
Using the PREVIOUS and NEXT commands does not
write to the BATCH page, therefore these commands can
be safely used without affecting the formula.
ERCBH2S warns the user if it is about to overwrite a
formula.
6.
Change the Pipe Diameter
To illustrate how segment lengths are adjusted for a given H2S volume, try
changing the Outside Diameter of one of the pipelines. Because the cells
are now ‘linked’ in a calculation sequence, changes to key cells cause
immediate changes to the Equivalent Segment Length.
As the Outside Diameter becomes smaller, the Equivalent Segment Length
becomes longer. As the Outside Diameter becomes larger, the Equivalent
Segment Length becomes shorter.
Tutorial Variation 1 – Complex Node Location
For this example, we examine how to organize, number, and label an input table
for a complex tie-in location.
ESD3
4
ESD1
ESD2
ESD4
1
9 Pipeline Gathering Systems
5
3
2
148
NODE TABLE
Node Number
N1
N2
N3
N4
N5
Node Label
(Flow Control)
ESD
ESD
-ESD
ESD
In this example, nodes 5 and 3 are actually at the same location.
BATCH Page Input Table
Scenario
Name
Column L
Upstream
Node
Number
Column
CO
Downstrea
m Node
Number
Column
CP
Upstream
Node Label
(Valve Type)
Column
CQ
Downstream
Node Label
(Valve Type)
Column
CR
Row 11
N1-N5
N1
N5
ESD
ESD
Row 12
N5-N3
N5
N3
ESD
--
Row 13
N4-N3
N4
N3
ESD
--
Row 14
N3-N2
N3
N2
--
ESD
BATCH
page
row
numbe
r
In this example, if only one node is described at the tie-in location, only one node
description can be assigned (remember that nodes must be unique). If the tie-in
is labelled as ESD, it indicates that all pipelines tying-into this location begin or
end with this ESD, which in this case is incorrect (e.g.: the pipeline coming from
node 4 does not end at the ESD). If we label the location as ‘open flow’, then it
indicates that all pipelines tying into this location begin or end with an ‘open
flow’, which is also incorrect (e.g.: the pipeline coming from node 1 ends at an
ESD). The only solution is to create two nodes at the tie-in location, labelling one
as an ESD, and the other as an ‘open flow’. Remember that the actual ‘physical
flow control’ for the beginning and ending of a pipeline segment must be
accurately described.
When describing complex tie-ins, the user must describe ‘short’ pieces of pipeline
connecting one node to another. These segments can be no shorter than 1 metre.
Beyond this, users should use actual lengths whenever possible. If the piping in
question is not part of the licensed system (as may be the case with certain lease
piping) it must be described anyway. Without it, the ERCBH2S ‘Gathering
9 Pipeline Gathering Systems
149
System Analysis’ calculation feature cannot correctly ‘sum’ the H2S mass of the
gathering system because the system is effectively ‘disconnected’ at this location.
Because lease piping may not have an ERCB licence number, the user can
indicate this in the Administrative section of the Inputs page (or the BATCH
page). For the line number, the user can indicate which pipelines are being
‘connected’ by the lease piping (helps to understand how the gathering system is
put together).
The last column in the following table illustrates how ERCBH2S ‘sums’ the H2S
mass described in this example.
BATCH Page Table
Downstream
Node
Number
Column
CP
Upstream
Node
Label
(Valve
Type)
Column
CQ
Downstream
Node Label
(Valve Type)
Column
CR
How
ERCBH2S
‘sums’
the H2S
Mass
BATCH
page
row
number
Scenario
Name
Column
L
Upstream
Node
Number
Column
CO
Row 11
N1-N5
N1
N5
ESD
ESD
= N1-N5
Row 12
N5-N3
N5
N3
ESD
--
= N5-N3 +
N4-N3
+N3-N2
Row 13
N4-N3
N4
N3
ESD
--
= N5-N3 +
N4-N3
+N3-N2
Row 14
N3-N2
N3
N2
--
ESD
= N5-N3 +
N4-N3
+N3-N2
Tutorial Variation 2 – Other Licensee Tie-in
In the following example, two different licensees are tied-in together at Node 2,
where there is no flow control. This means that each licensee must account for
H2S from the other licensee’s gathering system – to a point where flow control
9 Pipeline Gathering Systems
150
devices are encountered that stop additional material from entering the subject
group of pipelines. In this example, each licensee is submitting a separate
ERCBH2S file to the ERCB.
To arrive at an Equivalent Segment Length for each pipeline in this group, the
user can perform manual calculations according to section 5.4 of the VOLUME 1
Technical Reference Document. Alternatively, the Gathering System
Analysis portion of a ‘separate’ BATCH page can be used as a ‘calculator’ to
save time. This page will not be submitted to the ERCB because each licensee is
submitting a separate file pertaining to their respective pipelines.
Below is the BATCH page table for this pipeline group. The last column
identifies how ERCBH2S sums the H2S mass for this group. Notice that although
the check-valve at Node 6 prevents additional mass from being added back to
Row 15, mass from Row 15 is added to the rest of the pipelines in this group.
Also notice that although Nodes 6 and 7 are at the same location, they must be
identified separately (with a short piece of pipeline connecting them). If only the
check-valve was identified at this location, then the pipeline coming from Node 4
9 Pipeline Gathering Systems
151
would directly tie-into a check-valve, which is incorrect. Describing this location
in the manner shown ‘links’ all of the pipelines together, thereby allowing
ERCBH2S to correctly ‘sum’ the H2S mass.
BATCH Page Table
Scenario
Name
BATCH
page
Column
row
L
number
Row 11
Row 12
Row 13
Upstream
Node
Number
Downstream
Node
Number
Column
CO
Column
CP
N1-N2
N2-N3
N4-N7
N1
N2
N4
N2
N3
N7
Upstream
Node
Label
(Valve
Type)
Column
CQ
ESD
- -
ESD
Downstream
Node Label
(Valve Type)
Column
CR
How
ERCBH2S
‘sums’ the
H2S Mass
- -
=N1-N2
+N2-N3 +
N4-N7 +
N7-N2 +
N5-N6 +
N6-N7
ESD
=N1-N2
+N2-N3 +
N4-N7 +
N7-N2 +
N5-N6 +
N6-N7
- -
=N1-N2
+N2-N3 +
N4-N7 +
N7-N2 +
N5-N6 +
N6-N7
Row 14
N7-N2
N7
N2
- -
- -
=N1-N2
+N2-N3 +
N4-N7 +
N7-N2 +
N5-N6 +
N6-N7
Row 15
N5-N6
N5
N6
ESD
CV
= N5-N6
- -
=N1-N2
+N2-N3 +
N4-N7 +
N7-N2 +
N5-N6 +
N6-N7
Row 16
N6-N7
9 Pipeline Gathering Systems
N6
N7
CV
152
Remember, this particular BATCH page is being used only as a ‘calculator’; it
will not be submitted to the ERCB.
Once the Equivalent Segment Lengths have been calculated, they can be entered
manually in column AF on each licensee’s respective BATCH page. For
example, the pipeline described on this page as Row 12 may in fact be Row 185
on Licensee ABC’s BATCH page.
Remember that when manual calculation are entered in column AF, the user
MUST NOT ‘drag’ the formula from Cell AF10 over the manual entries (see Step
6 in the first Tutorial example in this chapter).
Formulae for Pipeline Networks
The formulae for the pipeline gathering system calculations in Excel are provided
in VOLUME 1 Technical Reference Document (section 5.4). The
ERCBH2S Gathering System Analysis feature determines the H2S mass of each
pipeline segment (determined using ideal gas properties, and based on licensed
maximums). The simplification ignores compressibility effects (z factor), and
assumes compressibility is similar between each segment. Actual compressibility
becomes a factor once dispersion modelling is performed.
Remember, for Equivalent Segment Length, if the pipeline inside diameter,
licensed maximum operating pressure and licensed H2S are the same, then the
segment lengths can be simply added together to arrive at the correct number. If
any of these factors are not the same, refer to section 5.4 of the Technical
Reference Document.
For Equivalent Cumulative Pipeline Volume, if the licensed maximum operating
pressure, minimum operating temperature and licensed H2S are the same for ALL
segments, then the calculation is the straightforward ‘sum’ of the segment lengths
times the pipe area. If any of these factors are not the same, refer to section 5.4 of
the VOLUME 1 Technical Reference Document.
9 Pipeline Gathering Systems
153
10.
EXAMPLE 1:
Gas Pipeline
Tutorial
By working through pre-loaded example files, you will become acquainted with:
•
the ERCBH2S screen in Excel,
•
some of the pages in ERCBH2S (Inputs and ERP Summary Page),
•
user controlled input data, and
•
terminology used throughout the guide.
If you have not done the tutorial ‘QUICK-START TUTORIAL’ (Chapter 3 page 16) please do it now.
If you have not read Chapter 5 - INPUTS PAGE (page 53), please do it now (it
is pre-requisite familiarity for the tutorials).
In ERCBH2S, emergency response and planning (ERP) zone calculations have
certain assumptions and processes to model the sour gas well release and its
subsequent behaviour. To acquaint the user with some of these attributes and
terminology, the following summary is provided:
Sour Gas Release Characteristics
•
Source conditions are determined for a high-pressure pipeline blow down.
•
Flow rate decreases as the high-pressure decreases as the release
progresses. Because the flow rate is not steady (not constant with time), a
sour gas pipeline release is called a ‘transient release’ (transient jet).
•
Flow from the pipeline (failure site) occurs at the mid-length location of
the pipeline segment to simplify the analysis.
Individual Pipeline Analysis versus a Gathering System Analysis
•
For an individual pipeline segment analysis:
10 Example 1: Gas Pipeline
154
o At each end of the pipeline segment there is an ESD valve or other
flow control device that can completely stop product flow into the
subject,
o the only source of product for the segment being modelled comes
from upstream and downstream of the segment (there are no other
pipelines tying-into the segment), and
o up-stream and downstream pipelines have identical specifications
as the segment being modelled – including expected maximum
operating pressure and expected maximum H2S concentration.
•
In real gathering systems where some pipeline segments may not begin
and/or end with a flow control device, or for segments that have other
pipelines ‘tying-in’ in-between the beginning and end of the pipeline
segment, ERCBH2S has a Pipeline Gathering System analysis
feature to account for these circumstances. This process is described in
Chapter 9 - Pipeline Gathering Systems. If you are modelling pipelines,
we STRONGLY recommend you read Chapter 9.
What a pipeline segment means to ERCBH2S
•
There are identical flow control devices at each end of the pipeline, and
both flow control devices close at the same time. Therefore, pipelines that
begin and end with ‘non-identical’ ESD valve settings, or have nonidentical types of flow control must be modelled with the ‘lowest’ valve
setting. Check valves are assumed to work correctly and completely.
•
There are no pipelines tying into the pipeline segment in-between the start
and end of the segment*. In the event of a failure, additional product flow
can only come from each end of the pipeline.
o *F.Y.I. - This is why segment lengths must sometimes be adjusted
(‘Equivalent’ Segment Length); because other pipelines tie into the
modelled pipeline in between the beginning and ending of the
modelled pipeline. Again, this is described in Chapter 9 - Pipeline
Gathering Systems. For this example, there are no pipelines tying
in between the beginning and ending of the segment, AND the
pipeline begins and ends with an ESD valve.
Flow Control
•
User inputs to ERCBH2S provide for the following types of flow control:
o ‘Low-pressure set point’ ESD control trigger - if pressure falls
below a pre-determined set point, the valve will close.
10 Example 1: Gas Pipeline
155
o ‘Pressure rate of change’ (PROC) ESD control trigger - if a predetermined pressure drop occurs over a pre-set sampling time – the
valve will close.
o Manual closure at a specified time after the release begins. The
time must include detection of the release, notification of the
operator, travel to the segment, verifying the release by locating it,
and shutting the valves.
o No flow control.
•
ESD valves have a specified time to shut-in (once activated to close - the
amount of time it takes them to close). This operation of the valve means
that gas from the pipeline will exit from both between the ESD valves
(volume based on the segment length), and from upstream and
downstream of the two ESD valves until closure is triggered (additional
gas volume). ERCBH2S calculates the total release volume – which
depends on the time it takes the valve closure to be activated.
•
Following valve closure, a pipeline continues to blow-down until the two
halves have drained to atmospheric pressure, unless the pipeline is ignited
or ‘drawn-down’. ERCBH2S inputs also provide for these very specific
pre-planned user actions.
Ground-level Release
A nominal height of 0 m is used in the air quality modelling simulations, as most
pipelines are buried and the release exits at ground-level. A large/high pressure
sour gas pipeline rupture is typically a catastrophic release that removes surface
soils and flattens the ground around the release site. Failures from leaks (small
holes) can also remove surface soils with their high-pressure ‘jet’ release (created
by the ‘choked flow’ effect).
Horizontal or Vertical Release
Sour gas pipeline releases are assumed to be horizontal releases resulting from a
catastrophic rupture of the pipeline. Less damaging ruptures or lower pressure
sour gas pipelines may have a deflected jet releasing vertically through soils (or
overburden), the resultant jet could be either horizontal (parallel to the ground
surface) or vertical (perpendicular to the ground surface). Because horizontal
releases do not rise as much as vertical releases, the horizontal release errs on the
side of caution.
Dense or Buoyant
A buried sour gas pipeline is typically at or near ground temperature of 5ºC.
When the flow exits the source (failure site) to atmospheric pressure, a ‘choked
10 Example 1: Gas Pipeline
156
flow’ condition occurs. Due to the expansion effects of the released material, its
temperature drops and initial dispersion conditions may be dense. ERCBH2S uses
real gas effects and determines whether the release is dense or buoyant.
Hole Size (Ae/Ap Ratio)
Pipelines can fail by a complete sever (guillotine rupture) - in catastrophic
fashion, or by leaks from a hole in a pipeline. Leaks from holes in sour gas
pipelines are also high-pressure releases (the ‘choked flow’ effect), but the
pipeline blow-down takes much longer than with a guillotine rupture.
Consequently, while the rate of release may be significantly smaller, the release
duration may be much longer. This is because ESD valve automatic closure
trigger ‘times’ may be significantly longer (i.e., ESD valves will not trigger
closure because the pressure drop is not significant enough, so a manual trigger
must occur).
In the case of a guillotine rupture, gas escapes through equally sized holes from
each half of the ruptured pipeline (200 % of the pipeline’s flow area). All other
failure hole size scenarios examined by ERCBH2S are considered as single holes
(≤100 % of the pipe area), also expressed as a release hole size fraction (Aexit/Apipe
or Ae/Ap).
Failure (Release) Location
For modelling, the failure (release) site is always the pipeline midpoint.
Step-By-Step Procedure
To follow along with this hands-on sour gas pipeline release example:
If you have pre-set the install option for ERCBH2S.xla (STEP 2:
Activating the ERCBH2S Add-In on page 12) go directly to step 2 in
this tutorial. Otherwise, begin at step 1.
1.
Click on the Start menu button on your computer desktop.
Select Programs
Select ERCBModels
Select ERCBH2S
Select Launch ERCBH2S.xla
(The ERCBH2S menu in Excel is now launched)
10 Example 1: Gas Pipeline
157
Choose ‘Enable Macros’
2.
Click on the Start menu button on your computer desktop.
Select Programs
Select ERCBModels
Select ERCBH2S-Inputs(V120).xls
3.
The Gas Pipeline example file already contains in the row 12 in the
BATCH page. Alternatively, you can move this record (row) from
BATCH page to INPUTS page follow the instruction in ‘From BATCH
to INPUTS’ (page 120). A complete description of all the entry cells is in
Chapter 5 - INPUTS PAGE (page 53).
ERP zones have already been calculated for the example file, and the results
are shown on the ERP SUMMARY page. If the user changes certain key
entries on the INPUTS page, the wording inside a red flag warning
banner (that will appear at the top and bottom of both the INPUT and ERP
SUMMARY pages) warns the user that re-calculations are required
(because user inputs are not = to the program outputs). If this type of
warning appears at anytime during this tutorial do not be alarmed. The ERP
zones (outputs) will be re-calculated in the last steps of the tutorial (using
the new inputs), thereby removing these particular red flag warnings.
red flag warnings are described in more detail in Chapter 5 under Red
Flags and other Warnings.
10 Example 1: Gas Pipeline
158
4.
Administrative Input Group
The entry titled ‘Surface Elevation’ is for an average EPZ elevation near the
pipeline based upon a review of topographical maps of the area within a
radius of about 5 km (determined from maps), or based on well-site
elevations. Pipelines with significant elevation changes must be modelled in
separate segments if elevation changes are more than +/- 100m. Additional
details concerning this and all other user inputs are in Chapter 5 - INPUTS
PAGE (page 53).
Try deleting some of the entries, and observe the warnings that appear in
column ‘E’. This column provides warnings for the user. Warnings also
appear inside a red flag warning banner across the top and bottom of the
page.
Select the ‘undo’ button to replace the entries, and the warnings will be
removed. Warnings are described in more detail in Chapter 5 under Red
Flags and other Warnings.
5. Calculation Controls portion of the ADMINISTRATIVE Group
10 Example 1: Gas Pipeline
159
For pipelines, Sour Operations Type is determined by a pipeline’s ERCB
Directive 056 licensed substance, with the exception of Acid Gas. Acid Gas
pipelines must be identified separately, even though they are licensed as
Sour Gas pipelines.
Use the drop-down box to select a pipeline substance. By trying different
selections, you will see that some choices move you to the Liquid
Pipeline/Well group. Replace the original selection of Sour Gas Pipeline.
6. Gas Pipeline Details Input Group
Notice that the Licensed Maximum Operating Pressure (MOP) is 9930 kPa
(gauge), but the ‘Expected Maximum Operating Pressure’ is only 5000 kPa.
There is a similar difference for the H2S entries – the Licenced Maximum
H2S Concentration is 14 %, but the Expected Maximum H2S Concentration
is only 7 %. Representative operating maximum values that are lower than
licensed limits and will not be exceeded can be used instead of
licensed maximums.
Now look at the two pipeline length entries. If this pipeline had ESD valves
(or equivalent) at each end, and there was no other pipeline tying into it, the
two length entries would be the same. For this example, it appears there is
either no ESD at one (or both) ends of the pipeline, and/or there are other
pipelines tying into the subject segment. ‘Equivalent Segment Length’ is
described in more detail in Chapter 9 - Pipeline Gathering Systems.
10 Example 1: Gas Pipeline
160
The Equivalent Cumulative Pipeline Volume cell appears greyed-out. This
is because a user must enter only ONE of either the Equivalent Segment
Length between ESDs (ESL) OR Equivalent Cumulative Pipeline Volume
(ECPV). Notice the entry in column D for the ECPV row - ERCBH2S has
calculated the equivalent volume based on other user entries.
Delete the 4973 entry for ESL, and both the ESL and ECPV cells are now
open for user input. Enter 253 for ECPV, and observe that the ESL entry is
greyed-out and column D displays the calculated length.
Delete the entry for ECPV. Enter 900 for ESL. An
Entry out of bounds
warning appears in column E because the
ESL between ESDs’ cannot be less than the Segment Length (allowable
entry ranges are displayed to the right of the INPUTS page – in columns H
and I). Also notice the red flag banner that appears at the top and bottom
of the page. The user entry is obviously an ‘out of bounds’ error and has to
be corrected for the model to run. Re-enter the 4973 and the ‘Entry out of
bounds’ warning disappears.
The ‘Modelled Solution Gas to Liquid Ratio’ cell is greyed-out because the
pipeline substance is not Oil Effluent (selected in ‘Sour Operations Type’ the Administrative section).
Additional details concerning these (and all other) user inputs are in
Chapter 5 - INPUTS PAGE (page 53).
7. Minimum Pipeline Temperature
Even though this pipeline has a line heater installed to prevent hydrate
formation, the normal minimum operating temperature is ground
temperature. Therefore, the default setting of 5° C is not changed.
Enter a value of 160, and the model input changes to 150; as indicated by
the ‘orange reset’ in column E. This is because the user entry is above the
allowable range for this field – as indicated in columns H and I (to the
right). Notice that column J describes the associated model action (for
entries outside the allowable range) as ‘resets’. This means that instead of
the user entry, the model will use the closest allowable value. Unless the
user entry is changed to be within allowable limits, a red flag will be
attached to the calculation results, and they will not be acceptable for ERCB
submission.
Delete the 160 entry, and the orange reset is removed. The model will
again use the default value of 5° C.
10 Example 1: Gas Pipeline
161
Warnings are described in more detail in Chapter 5 under Red Flags and
other Warnings.
8. Source Mitigation
The SOURCE MITIGATION sub-section is not currently ‘open’ because
the NO MITIGATION analysis type is selected in the
ADMINISTRATIVE section of the INPUTS page. The model will use
the default values as shown.
Note that the ERCB default settings in this group result in no effective
ESD control for a pipeline release.
GAS PIPELINE source mitigation is discussed in more detail under Gas
Pipeline Group- Source Mitigation Section in Chapter 5.
9. Sour Gas Composition Input Group
The gas composition (mole fraction) for the example pipeline segment
release is provided. This particular sample represents a composite average
of sour wells in Alberta, and is intended for use only in this tutorial (users
must supply appropriate representative analysis data for the sour gas
pipeline being modeled).
Sour Gas Composition
Units
User Input
H2
He
N2
CO2
mole fraction
mole fraction
0
0.0006
0.0283
0.0427
H2S
mole fraction
0.0259
CH4
C2H6
C3H8
i-C4H10
n-C4H10
i-C5H12
n-C5H12
n-C6H14
mole fraction
+
mole fraction
0.8137
0.0488
0.0208
0.0036
0.0065
0.002
0.0021
0.002
0.003
1
(gas phase at 15°C & 101.325 kPa, dry,
representative analysis)
n-C7H16
Total
10 Example 1: Gas Pipeline
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
mole fraction
Comments
Warnings
Adjusted to Maximum H2S Input for
Level and Modelled H2S Input for EPZ
Sum must equal one
162
Observe the comment in column D beside the H2S entry. For this particular
example file, this comment means that although the gas analysis H2S
content is less than 3 %, the analysis will be re-adjusted to the Expected
Maximum H2S Concentration of 14 % (entered in the GAS PIPELINE
details group). The Licensed Maximum H2S Concentration (14 %) is used
for setback calculations, and not for planning zone calculations.
In adjusting a gas analysis composition, ERCBH2S changes the reference
H2S entry to equal the ‘Maximum Expected H2S’ entry, and then pro-rates
all other reference gas analysis components according to their new fractional
contribution to the total analysis (renormalized). The adjusted analysis can
be immediately viewed on the ERP SUMMARY page, because the
calculations are performed by Excel – no ERCBH2S program ‘run’
commands are needed for the conversion. All ERCBH2S program
modelling calculations will reference the adjusted analysis.
See Sour Gas Composition in Chapter 5 for more information.
10. Run Calculate EPZ
After pressing the Calculate EPZ button,
, a confirmation dialog is
presented, asking if you are sure you want to continue. The calculations
10 Example 1: Gas Pipeline
163
may take several moments to perform depending on the processing power of
the computer used. Select OK to continue.
After the ERCBH2S calculations are completed, the ERP SUMMARY page
is displayed to view a summary of the calculation results.
11. ERP SUMMARY Page Results
The ERP SUMMARY page displays a planning and response zone graphic,
as shown below.
The table to the right of the schematic lists each of the emergency response and
planning zones.
Variation 1: Segment Length
The Equivalent Segment Length considered above was 4973 m between
ESD valves. Next we consider another segment of the same pipeline. The
distance between ESD valves is 1000 m in this segment, whereas all of the
other conditions are the same. ERP zones must be defined for each segment
of the pipeline, because the blow-down calculations for each segment will
be different.
Click on the INPUTS page and change Segment Length and Equivalent
Segment Length in the Gas Pipeline details input group to 1000.
10 Example 1: Gas Pipeline
164
, from the button-bar or menu
Click on the Calculate EPZ command,
to re-run the calculations for the new segment. The new results will look
like the table displayed on the ERP SUMMARY page and shown below:
Notice that the EPZ distance has decreased but not as much as you were
expecting. All of the zones have decreased but not in the same proportions.
V1. Variation 2: WITH MITIGATION Analysis (PROC Valves)
You are contemplating purchase of new ESD valves. Before you purchase
the valves, you examine whether this new technology has any impact on the
calculated emergency response planning zones.
Because ESD valves are now a consideration, the user has checked with
appropriate company personnel for the maximum time to manually close
ALL valves for this pipeline segment (in the actual location/locale) from the
time a leak begins. Very small pipeline release failures may not activate
ESD valve closure settings.
10 Example 1: Gas Pipeline
165
V2. On the INPUTS page in the ADMINISTRATIVE inputs group – Analysis
Type, select a WITH MITIGATION analysis.
In the GAS PIPELINE details group, change ‘Equivalent Segment Length’
back to 4973.
Because this is a tutorial, the user inputs for SOURCE MITIGATION in
GAS PIPELINE have been already entered. Notice the ‘over-ride’ of most
of the default entries (ERCB default settings in this group result in no
effective ESD control for a pipeline release).
To see the effect the new ESD valves could have on the planning zone
sizes, the pipeline will be modelled with flow completely controlled using
PROC-ESD’s of identical settings. Also, the time for manual closure
applies to ALL of the valves for the pipeline segment. (Remember that the
flow control device with the lowest setting must be modelled. GAS
PIPELINE source mitigation is discussed in more detail under Gas
Pipeline Group- Source Mitigation Section in Chapter 5.)
The entries correspond to the ESD specification of a Valve Closure time of
1 s and a sensitive PROC trigger of 100 kPa/s that is sampled every 60 s. In
addition, the valves have a low pressure setting, which (to be effective) will
not be set at less than 50 % of the Expected Maximum Operating Pressure
(this is the ERCB expectation for sour gas pipelines with greater than 1 %
H2S).
10 Example 1: Gas Pipeline
166
V3. Click on the Calculate EPZ command,
, from the button-bar or
menu to re-run the calculations for the new entries. The new results
will look like the table displayed on the ERP SUMMARY page and
shown below:
On the ERP SUMMARY page, the hazard zones are significantly reduced
from the NO MITIGATION ESD instrumentation settings. These results
may be advantageous from an emergency planning perspective and for
general public safety. It remains to be examined by the operator if the
normal fluctuation of pressure through the pipeline segment (due to process
or load fluctuations) may trigger false ESD closures.
10 Example 1: Gas Pipeline
167
11.
EXAMPLE 2:
Gas Well
Tutorial
By working through pre-loaded example files, you will become acquainted with:
•
the ERCBH2S screen in Excel,
•
some of the pages in ERCBH2S (Inputs, Batch and ERP Summary Page),
•
user controlled input data, and
•
terminology used throughout the guide.
If you have not done the tutorial ‘QUICK-START TUTORIAL’ (Chapter 3 page 16) please do it now.
If you have not read Chapter 5 - INPUTS PAGE (page 53), please do it now (it
is pre-requisite familiarity for the tutorials).
In ERCBH2S, emergency response and planning (ERP) zone calculations have
certain assumptions and processes to model the sour gas well release and its
subsequent behaviour. To acquaint the user with some of these attributes and
terminology, the following summary is provided:
Sour Gas Release Characteristics
•
Source conditions are determined by reservoir engineering. Flow rate to
surface is not regulated by engineering controls and the failure is typically
an uncontrolled-high pressure, high flow rate, low temperature release.
•
A sour gas well release is typically a steady flow rate (constant with time)
release (steady jet).
Release Height
A nominal height of 1 m is used in the air quality modelling simulations. Well
releases typically result from a loss of control situation (during drilling, workovers, completion or re-completion), or during production, with the emission
point to atmosphere at or near ground level.
11 Example 2: Gas Well
168
Horizontal or Vertical Release
A sour gas well release jet could be re-directed as a result of interaction with
nearby obstacles such as the rig itself or piping. The release jet could also be
from a malfunction or piping failure at the well head. Therefore, the resultant jet
could be horizontal (parallel to the ground surface) or vertical (perpendicular to
ground surface). A horizontal release, which errs on the side of caution, is
assumed in ERCBH2S.
Dense or buoyant
A sour gas well is supplied by a reservoir at high pressure and high temperature.
As the release flows up the well bore it cools due to expansion and transfers heat
to the ground. Using a stagnation temperature, ERCBH2S determines the exit
pressure according to the specified flow rate. When the flow exits the well bore
to atmospheric pressure, a choked flow condition occurs. Resulting expansion
effects cause temperature drop, creating initial dispersion conditions that may be
dense. ERCBH2S selects the stagnation temperature which results in a dense
release, thereby erring on the side of caution.
Step-By-Step Procedure
To follow along with this hands-on sour gas well release example:
If you have pre-set the install option for ERCBH2S.xla (STEP 2:
Activating the ERCBH2S Add-In on page 12) go directly to step 2 in
this tutorial. Otherwise, begin at step 1.
1.
Click on the Start menu button on your computer desktop.
Select Programs
Select ERCBModels
Select ERCBH2S
Select Launch ERCBH2S.xla
(The ERCBH2S menu in Excel is now launched)
Choose ‘Enable Macros’
2.
Click on the Start menu button on your computer desktop.
Select Programs
11 Example 2: Gas Well
169
Select ERCBMODELS
Select ERCBH2S
Select ERCBModels
Select ERCBH2S-Inputs(V120).xls
3.
The Gas Well example file already contains in the row 11 in the BATCH
page. Alternatively, you can move this record (row) from BATCH page to
INPUTS page follow the instruction in ‘From BATCH to INPUTS’
(page 120). A complete description of all the entry cells is in Chapter 5 INPUTS PAGE (page 53).
ERP zones have already been calculated for the example file, and the results
are shown on the ERP SUMMARY page. If the user changes certain key
entries on the INPUTS page, the wording inside a red flag warning
banner (that will appear at the top and bottom of both the INPUT and ERP
SUMMARY pages) warns the user that re-calculations are required
(because user inputs are not = to the program outputs). If this type of
warning appears at anytime during this tutorial do not be alarmed. The ERP
zones (outputs) will be re-calculated in the last steps of the tutorial (using
the new inputs), thereby removing these particular red flag warnings.
INPUTS DO NOT MATCH DISPLAYED OUTPUT PAGES -- RECALCULATIONS REQUIRED: ,ERCBFlash,ERCBSlab,MetMatrix
Red flag warnings are described in more detail in Chapter 5 under Red
Flags and other Warnings.
11 Example 2: Gas Well
170
4.
Administrative Input Group
Try deleting some of the entries, and observe the warnings that appear in
column ‘E’. This column provides warnings for the user. Warnings also
appear inside a red flag warning banner across the top and bottom of the
page.
Select the ‘undo’ button to replace the entries, and the warnings will be
removed. Warnings are described in more detail in Chapter 5 under Red
Flags and other Warnings.
Use the drop-down box to select the pipeline substance category according
to ERCB Directive 056. Acid Gas pipelines must be identified separately,
even though they are licensed as ‘Sour Gas’ pipelines.
5. Calculation Controls portion of the ADMINISTRATIVE Group
For wells, ‘Sour Operations Type’ is determined by the well’s ‘ERCB
Directive 056’ substance, and the wells’ Gas to Liquid Ratio (GLR).
Use the drop-down box to select the substance. By trying different
selections, you will see that some choices move you to the ‘Liquid
Pipeline/Well’ group. Replace the original selection of ‘Sour Gas Well’.
11 Example 2: Gas Well
171
6. Gas Well Details Input Group
There are three types of ‘Phase of Well Operations’: Drilling,
Completion/Servicing/Workover, and Producing/Injection/Suspended.
Try deleting the 165.6 entry and entering 1656, a typo. Notice the
Entry out of bounds
warning appears in column E because the
Casing or Tubing Inside-Diameter must not be greater than 500 mm
(allowable entry ranges are displayed to the right of the INPUTS page – in
columns H and I). Also notice the red flag banner that appeared at the top
and bottom of the page. The user entry is obviously an ‘out of bounds’ error
and has to be corrected for the model to run. Re-enter the 165.6, and the
‘Entry out of bounds’ warning disappears.
11 Example 2: Gas Well
172
7. Source Mitigation
The SOURCE MITIGATION sub-section is not currently ‘open’ because
the NO MITIGATION analysis type is selected in the
ADMINISTRATIVE section of the INPUTS page. The model will use
the default SCSSSV option and mitigation time as shown.
See Gas Well – Source Mitigation Sub-section in Chapter 5 for
more information.
Note that for wells, the default setting for ‘Time from initial release until
ignition or stop flow’ changes with the Phase of Well Operation – which
indicates if the site is manned or un-manned (subsequently affecting the
time to implement mitigation measures).
For Producing/Injection/Suspended wells with a SCSSSV, the default
minimum ‘Time from initial release until ignition or stop flow’ is 3-minutes.
For Drilling or Completion/Servicing/Workover wells with a SCSSSV, the
11 Example 2: Gas Well
173
default minimum ‘Time from initial release until ignition or stop flow’ is
15-minutes.
If the User Input is out of the range of the default settings, the MODEL
INPUT cell gives an Orange Warnings. For example, for a Drilling well, if
the user inputs 3-minutes for ‘Time from initial release until ignition or stop
flow’, the MODEL INPUT cell shows a warning. Because the user input is
less than the default minimum 15-minutes ignition time for a drilling phase.
However, if the user chooses a Producing phase instead of a Drilling phase,
the 3-minutes ignition time is acceptable because the minimum ignition time
for a Producing phase is 3-minutes. The MODEL INPUT cell does not show
any warnings here.
The default setting for ‘Time from initial release until
ignition or stop flow’ changes with the Phase of Well
Operation.
It is user’s responsibility to choose the correct Phase of
Well Operation.
11 Example 2: Gas Well
174
8. Sour Gas Composition Input Group
The gas composition (mole fraction) for the example well file is provided.
This particular sample represents a composite average of sour wells in
Alberta, and is intended only for use in this tutorial (users must supply
appropriate representative analysis data for the sour gas well being
modeled).
Observe the comment in column D beside the H2S entry. For this particular
example file, this comment means that although the gas analysis H2S
content is less than 3 %, the analysis will be re-adjusted to the expected
maximum H2S concentration of 14 % (entered in the GAS WELL details
group).
In adjusting a gas analysis composition, ERCBH2S changes the reference
H2S entry to equal the ‘maximum expected H2S’ entry, and then pro-rates all
other reference gas analysis components according to their new fractional
contribution to the total analysis (renormalized). The adjusted analysis can
be immediately viewed on the ERP summary page, because the calculations
are performed by Excel – no ERCBH2S program ‘run’ commands are
needed for the conversion. All ERCBH2S program calculations will
reference the adjusted analysis.
11 Example 2: Gas Well
175
See Sour Gas Composition in Chapter 5 for more information.
9.
Run Calculate EPZ
After pressing the Calculate EPZ button,
, a confirmation dialog is
presented, asking if you are sure you want to continue. The calculations
may take several moments to perform depending on the processing power of
the computer used. Select OK to continue.
After the ERCBH2S calculations are completed, the ERP SUMMARY page
is displayed to view a summary of the calculation results.
10. ERP SUMMARY Page Results
The ERP SUMMARY page displays a planning and response zone graphic,
as shown below.
11 Example 2: Gas Well
176
The table to the right of the schematic lists each of the emergency response
and planning zones.
11. Saving data to the BATCH Page
Save entries from the INPUTS page to the BATCH page, by pressing the
Save INPUTS and Results to Batch Page button,
, while on the
INPUTS page. This command also saves all calculation results –
including the OUTPUT data.
Select the BATCH page tab. Notice that row 11 has entries. Scroll across
the sheet to see the inputs and outputs. Further changes to this scenario can
now be made directly on the BATCH page. When the new scenarios are
‘run’, the calculation results can be easily compared to each other because
the results will be listed one over the other – all within one column and all
of one page. For example, calculated EPZ results are listed in column DO
on the BATCH page.
Variation 1, performed from the BATCH page, provides important practice
in working between the BATCH and INPUTS pages. The actions
described are applicable to other ERCBH2S applications – not just sour gas
wells.
Variation 1: Sour Gas Well – Change Time to Ignition
Additional information has been obtained for this sour gas well through
expert training and testing on-site. The report suggests that the well could
be ignited if required in 12 minutes. Although your expert testing and
11 Example 2: Gas Well
177
documentation indicates 12 minute ignition time is possible, ERCB
Directive 071 does not allow for ignition times of less than 15 minutes.
On the BATCH page, duplicate the first scenario/row you entered (previous
step 11) using Excel’s usual ‘click and copy’ feature to copy the row’s
INPUT details (which end at column DN); then append/paste them to the
same range in row 12. Now avoid making changes to row 11 on the
BATCH page to maintain the input and output data integrity of this row.
Change the scenario name for the new row (row 12) in column L
on the BATCH page.
Use caution if you chose to copy the OUTPUT results from the original
scenario and apply them to the newest scenario. If you did, the safest
option is to simply delete them for the new row/scenario (OUTPUTS begin
at column DO). Otherwise, future input changes for the new row may
appear to coordinate with ‘old’ output results since they are also on the
same row on the BATCH page. Eventually, the new inputs will be used for
new calculation but until then, it is better not to list false results.
The ‘Erase all output fields’ button
does not erase
anything stored on the BATCH page – it erases outputs from
other ERCBH2S pages.
V1a. Scroll over to column BA in the Well Details Group (Time from initial
release till ignition or stop flow) and enter 12 (do not include units of
minutes).
V1b. Now ensure the new scenario/row is flagged appropriately for ‘run/not
run’. The Run/Not Run column (column ‘A’) should have a 1 in it to
ensure the new scenario is ‘run’ when one of the ERCBH2S program-RUN
commands is activated. You may wish to change the Run/Not Run
indicator of the last scenario/row to a 0 since calculations for this scenario
do not need to be repeated.
V1c. Click on the row number for the new row/scenario (extreme left side of
the BATCH page). Then click on the Copy current batch record to
INPUTS command,
from the button bar. This copies the entries for
the new scenario over to the INPUTS page. The screen automatically
changes to show the INPUTS page, populated with input data from
whatever row was highlighted on the BATCH page.
11 Example 2: Gas Well
178
Note - this is the only way to view any data entry warnings and/or
‘orange re-sets’.
Red flag warning banners, orange warnings and orange
resets related to user inputs do not appear on the
BATCH page.
V1d. Scroll down the INPUTS page to ‘Time from initial release till ignition or
stop flow’ in the Gas Well details group under Source Mitigation. Notice
that although you entered 12 minutes for this entry on the BATCH page,
the field is ‘greyed out’ on the INPUTS page; and the ‘Model Input’ value
assigned to this field is 720 minutes (shown in the right-hand column).
This is because in the Administrative section, the Analysis Type selected is
still NO MITIGATION. Change it WITH MITIGATION.
Now your entry of 12 minutes is allowed to appear. This input was brought
over from the BATCH page with all of the other inputs, but appeared
‘greyed-out’ because access to Source Mitigation was not activated.
Observe that in the right-hand column under Model Input, ERCBH2S has an
‘orange reset’ entry of 15 minutes.
This is because 15 minutes is the minimum allowed value for this field.
Toggle back over to the BATCH page. Notice that the option selected in
column N (Analysis Type) is still a 1 (NO MITIGATION). When this
option was changed on the INPUTS page, the change was not
automatically reflected on the BATCH page.
Input data on the BATCH page is only changed by either
‘over-writing an existing scenario on the BATCH page
with a new INPUTS page (same scenario name), or by
directly making the data change on the BATCH page.
For any given scenario, there is no ‘live/active link’
between the BATCH and INPUTS page.
11 Example 2: Gas Well
179
Also notice that the user input for column BA (Time from initial release till
ignition or stop flow) is still 12 minutes, even though you know the model
will use 15 minutes.
When ERCBH2S assigns a different value to a user entry
(an ‘orange reset’), the ‘reset’ value does not appear on
the BATCH page. The only way to see an ‘orange reset’
for a BATCH page scenario/record is to view the record
on the INPUTS page.
V1e. For practice, make the needed changes from the INPUTS page rather than
making them directly on the BATCH page.
Toggle back over to the INPUTS page. It appears EXACTLY as you last
left it. Because ‘Analysis Type’ is already changed to WITH
MITIGATION, the only other needed change is the user input in ‘Source
Mitigation’. Change the entry from 12 to 15, and the ‘orange reset’ is
removed.
V1f. Now you will ‘over-write’ a scenario on the BATCH page with a new
INPUTS page.
Recall that when an INPUTS page is saved to the BATCH page, ALL
calculation results (including OUTPUTS) go with it. Right now the ERP
SUMARY page still has calculation results from the last scenario that was
‘run’, and you do NOT want these results to be saved for your new row on
the BATCH page.
When copying an INPUTS page to a BATCH
page, ALL calculation results (including
OUTPUTS) are appended/copied to the
BATCH row/record.
However, when copying/reading a BATCH
record/row to the INPUTS page, only the
BATCH input records are copied over. Any
associated calculation results for the BATCH
row/record are not brought along.
Activate the ‘erase all output fields’
button to re-set calculation results
to ‘0’ before moving the INPUTS page to a BATCH record.
11 Example 2: Gas Well
180
From the INPUTS page, activate the SAVE TO BATCH button
.
Because the scenario name already exists on the BATCH page, the user is
prompted to either accept the save operation or to cancel. Choose the ‘save’
operation, and the record on the BATCH page with the identical
SCENARIO NAME is completely overwritten with the new data from the
INPUTS page (including whatever calculation results and output data is
tied to the INPUTS page).
V1g. View the changed row on the BATCH page. Go to the outputs area
(column DO) and observe the recorded outputs. Recall that you erased the
outputs before you performed the save. Also notice the error messages in
column DO, cautioning the user that the outputs listed do not match the
inputs. This message appears because it was copied over when you
performed the save. Messages in this column are not activated by simply
changing information on the BATCH page. They are recorded only
through either a ‘SAVE TO Batch’ operation, or when a scenario on the
BATCH page has received a ‘Batch Calculate EPZ’ command (or
other program ‘run’ commands).
V1h. Finally, activate the Batch Calculate EPZ command,
from the
button-bar at the top of the BATCH page. This executes the complete set
of 54-meteorological cases in the screening matrix calculation for each
scenario/row on the BATCH page that is included in the ‘run’ (has a ‘1’ in
column ‘A’ on the BATCH page).
V1i. The new results will look like the table displayed on the ERP SUMMARY
page as shown below:
11 Example 2: Gas Well
181
V1j. To compare the EPZ results from the first scenario to the new scenario, go
to column DP on the BATCH page. Notice that the EPZ distance has
decreased. In fact, all of the zones have decreased but not in the same
proportions.
11 Example 2: Gas Well
182
12.
Troubleshooting and FAQs
Non-reportable Error Messages
Many of the error messages are shown to assist the user. They have been
generated as a result of user inputs that create calculation errors or that something
non-routine has occurred and the program is trying to recover. Most of these
types of errors follow from inputs that exceed normal ranges of the parameter. To
problem solve these error messages, follow the steps below:
1. Review the inputs relating to the error message. Ensure that the inputs are
within the normal ranges for the field-operation and within the normal
range suggested in the spreadsheet input. Check for missing inputs. Reread the User Guide or Technical Reference Document to ensure that you
have interpreted the inputs correctly for what the program expects.
2. Use the example inputs provided in the User Guide as a starting point for
your assessment of the operation. Then change the example inputs to
match your conditions. (Remember to save the file with a new name so
the original template file is not changed).
3. Compare each input to one of your own assessments that works correctly.
4. If all of your inputs appear satisfactory, but an error message still occurs,
then report the error message and provide a copy of the inputs to ERCB.
See section ‘Reportable Error Messages’.
Reportable Error Messages
While every attempt has been made to ensure programming errors and
compatibility issues don’t arise, computer configurations vary by personal
preferences and therefore issues may arise. If an issue is discovered, please report
it to ERCB for inclusion in the next ERCBH2S release along with a copy of the
spreadsheet that may duplicate the error, to:
[email protected]
13 References
183
ERROR #9
This error message could result from a software compatibility error. Contact
ERCB and send the ERCB a copy of your spreadsheet that duplicates the error
message occurrence along with a description of how to duplicate the error
message.
ERROR #1004
This error message may occur due to a programming error or compatibility issue.
If modelling pipelines with very short line lengths (less than 10 m), try increasing
the line length 1 metre at a time to see if ‘Calculate EPZ’ can be executed without
getting the same message. You shouldn’t need to go higher than about 10 metres.
If this solves the problem, then simply subtract the extra line length from the
adjoining pipelines.
ERROR #9005
This error message is a result of the ERCBH2S FLASH program encountering
‘solving’ difficulties based on user inputs.
First, user inputs should be reviewed for accuracy. If all inputs are correct,
sometimes small changes to the inputs will help the FLASH program overcome
13 References
184
the ‘solving’ difficulties. Although the following recommended ‘alterations’
require a user to deviate from the actual ‘real’ input scenario, the deviations are
very minor and would not be considered in any ERCB enforcement action. If
slight alterations to a user’s inputs are necessary to help the FLASH program
solve, the input changes should be noted in a letter to the ERCB that accompanies
the ERCBH2S submission.
Suggested input ‘alterations’ and acceptable degree of variation from ‘actual’
values:
1.
Tubing or Casing Inside-Diameter affects the back pressure – first
make sure the input diameter, H2S release rate and H2S concentration
are reasonable. Does the cac pressure in INUTS K57 seem
reasonable? Try increasing the diameter slightly. Sometimes a change
of only 1 mm solves the FLASH problem. Do not change this input
more than 10 %.
2.
Gas Analysis – try changing some of the heavy ends. Add the C7’s to
the C6’s. If this doesn’t work, add the C7’s and C6’s, to the C5’s. If
this doesn’t work, add the C7’s, C6’s and the C5’s, to the C4’s. Do
not change an analysis anymore than this. While analysis changes like
these do not normally affect the size of the EPZ, they may help the
FLASH program to solve.
3.
Temperature – if temperature was available as a user input, try
changing the temperature a few degrees. Do not change the
temperature by more than a few degrees.
Version Issue
ERCBH2S was tested to operate with Excel 2000 (Excel Version 9), 2002 (Excel
Version 10), 2003 (Excel Version 11), 2007 (Excel Version 12), and 2010. While
every attempt has been made to ensure compatibility issues don’t arise, computer
configurations vary by personal preferences and therefore compatibility issues
may arise. If an issue is discovered, please report it to ERCB for inclusion in the
next ERCBH2S release.
There have been reported issues related to running the ERCBH2S Application
with Excel 97. The ERCBH2S Application is not supported on Excel 97.
13 References
185
Installation Troubleshooting
1.
Administration Privilege for Windows
During software installation, the Windows operating system may display a
message regarding a requirement for Administrator Privilege to install
the software. To check if you have Administrator Privilege for the
account you use to Logon into Windows, follow these steps:
a. Click the Windows Start button, select Settings, choose
Control Panel.
b. Double click the User Accounts icon.
c. If you account Logon is displayed at the bottom of this window
with the description: Computer Administrator, you have the
correct administrator privileges to install the software.
Program Troubleshooting
Not an ERCBH2S Spreadsheet
This error message may be displayed if a ERCBSLAB application menu or
calculation was attempted on an Excel spreadsheet that was not a recognized
ERCBSLAB spreadsheet.
General Troubleshooting
Excel Security Levels and Running the ERCBSLAB Application
If your Excel security setting is High, the ERCBH2S application may be
prevented from running. You can either reset your security level to allow it
13 References
186
to run or add the ERCBH2S add-in via the Add-In manager. Check with
your computer network administrator regarding security level protection and
running add-in macros on your computer.
Interfacing with other User Spreadsheets
The Batch page is designed to be flexible and adaptable to user
modifications for linking to in-house databases or networks. Data in the
Batch page:
•
can be a stand alone database for user;
•
can be expressions referencing values in the user database;
•
although columns cannot be created or destroyed, cells to the right of
the Batch records can be modified as the user requires to link their
database to this required input cells;
•
rows cannot be created or destroyed due to the security protection on
the datasheet. However, information in the row can be erased
(cleared) and gaps between rows can be filled by moving the data in
the rows up or down to accommodate the gaps;
•
use of the Silent Start option allows interfacing of ERCBH2S with
programs such as Crystal Ball© and @Risk©.
13 References
187
ERCBFLASH ERRORS
The following error numbers may be returned from the ERCBFLASH
program. These errors typically result from extreme gas compositions
where chemical-physical properties are difficult to predict or where critical
levels are reached and phase changes may occur. To correct the problem,
the gas composition may be documented and modified slightly.
ERCBH2S
ERROR CODE
ERCBFLASH
ERROR CODE
9000
0
Normal termination
9001
1
Error: Pure Helium specified Complete Data not
available in database
9002
2
Bad source type specification: It can be only 1
or 2 for Pipeline or Well respectively
9003
3
Error All Input Components' Compositions are
Zero
9004
4
The initial conditions of the source type not set
properly
9005
5
Flash Calculation Failure Please Check the
Input Data
9006
6
Failure in Bubble Temperature Calculations.
Please Check the Input Data
9007
7
Cp Vapour Calculation Failure Please Check
the Input Data
9008
8
Maximum Iterations Exceeded during ambient
pressure critical flow checking
9009
9
Error Calculating Isentropic Back Pressure for
subsonic flow
13 References
DESCRIPTION
188
ERCBSLAB ERRORS
The following error codes are returned from ERCBSLAB. These Error
codes in ERCBH2S are prefixed by 5000.
ERROR CODE
ERCBH2S
ERCBSLAB
ERROR CODE
DESCRIPTION
5000
5001
0
1
5003
3
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
6022
1022
6023
6024
6025
6026
6027
1023
1024
1025
1026
1027
Normal program termination. No errors detected
Zo <0 termination flag set. The original SLAB program used Zo
to control looping. This flag has been maintained for
consistency.
Source height too tall. Input source height (hs) is greater than
the calculated mixing layer height (hmx) minus the stack half
width (bs).
Invalid Input Parameter Errors
WMS Molar mass of source material was <=0. or >1.0 kg/mole
CPS, Vapour heat capacity was <=100. or >10000.0 J/kg/K
TBP, Boiling point temperature was <=1. or >1000.0 K
CMEDO, Initial liquid mass fraction was <0. or >1.0
DHE, Heat of vaporization was <1.E2 or >1.E12 J/kg
CPSL, Liquid specific heat was <100. or >1.E6 J/kg/K
3
RHOSL, liquid density was <.1 or >1.E4 kg/m
xxALPHA, Time factor was <0.
xxBETA, time constant was <0., s
TN, Concentration exponent for toxic load was <0. or >10.
TKL, Toxic load factor to account for fluctuations was <0.
TACH, Building air changes per hour was <0.
TH2S, Percent H2S in source mixture was <=0. or >100 %
TS, Temperature of source material was <23.K or >1273.K
QS, Mass source rate was <0.0 kg/s
2
AS, Source area was <0.0 m
TSD, Continuous source duration was < 0 kg
QTIS, Instantaneous source mass released was <0. kg
HS, Source height was < 0 m
HS, Source height was < 0 m
XFFM, Maximum downwind distance for ERCBSLAB
calculations was <1 or > 30000 m
ZA, Reference height for ambient wind speed anemometer was
<1 or >100 m
UA, Ambient wind speed was <0 or >100 m/s
TA, Ambient temperature was <173K or >373K
RH, Relative Humidity was <0 or >100 %
PA, Atmospheric pressure was <60000. or >105000.0 Pa
STAB, Stability class number was <0 or > 7
13 References
189
FAQs
Issue: Sweet pipeline tie-in to a sour gathering system.
A company is tying a sweet pipeline into one containing H2S. Since the model
assumes flow from either end of the pipeline until the ESD shuts, the company
assumes that there will be a possibility of H2S flowing back into the sweet line,
and that therefore there could be a release. The company has tried to model this
sweet line and the sour one, assuming the model will account for the backflow
and provide a small EPZ for the sweet line.
Answer:
ERCBH2S only has the capability of modelling gas that contains H2S. When a
company enters 0 % H2S into the model, it is forced to divide by zero, producing
no answer. The key message is that the ERCB has never asked companies to
account for backflow and calculate EPZs for sweet lines. The model is not built to
handle that calculation. Therefore companies should assume 0 m EPZ on all sweet
lines.
Issue: How do ESDs and check valves (CV) differ in the model?
A company indicates in its model that a pipeline has an ESD on one end of its line
and a CV on the other end. Given that a CV immediately prevents backflow, the
company assumed that any additional flow to the line between the time of a
pipeline release and the time the ESD shut would only come from the end of the
line where the ESD is located. However, when the company ran the model, a
much larger EPZ than anticipated was predicted.
Answer:
ERCBH2S treats ESD valves and check valves the same for EPZ calculations.
This means that the model assumes there could be backflow into a line, when in
reality there would not be. The model was written this way for simplicity. If there
is enough concern from industry, we may recommend that the model be changed.
Issue: Large EPZs on very short lines.
In some instances a line that is only 5 or 10 m in length can have EPZs several
kilometres in diameter.
Answer:
13 References
190
There are three main things to look for here:
•
whether the company has used mitigation or not,
•
what the pressure rate of change on the ESDs is, and
•
what the upstream and downstream line properties are.
The model assumes infinite flow from both upstream and downstream of a
pipeline. Therefore a short line with no mitigation or a very low pressure rate of
change (10 %) will have continual flow into it from both upstream and
downstream. To mitigate this, the applicant must increase its pressure rate of
change to ensure that the ESDs close sooner.
Issue: What does the ESD valve low pressure trigger mean?
Answer:
The low pressure trigger is the pressure set point where the ESDs on a pipeline
close. The model asks companies to enter this value as a pressure value (kPa), but
it is commonly discussed in terms of percentages. A low pressure trigger of 10 %
means that the pipeline has to depressure to 10 % of its total operating MOP
before the ESDs will close. Essentially, the pipeline must be empty before the
ESDs close. This means the associated EPZ will be very large, almost equal to a
case using no mitigation. A low pressure trigger of 90 % is generally
unreasonable, as daily fluctuations in pipeline pressure would cause the ESDs to
close. Many companies choose to use a low pressure trigger somewhere in the
range of 50 %.
Issue: Lines with differing lengths having very similar EPZs.
All other input being equal, why do lines with differing lengths have virtually the
same EPZ?
Answer:
The first this to do is check whether the company has modelled the lines using
mitigation or not. If they have not (which will most likely be the case in these
scenarios), the model assumes that the line will flow for 12 hours before the ESDs
shut. If they have chosen “With Mitigation” but have a very low “low pressure
trigger” (say, 10%), this is virtually the same as having no mitigation at all. The
model assumes that the sections upstream and downstream of the ESD are infinite
and will supply as much gas as needed until the pressure drops to the set point or
the valves are closed manually. By selecting “With Mitigation” and entering
values above the default, the EPZ becomes more sensitive to the line length.
Issue: The .csv file will not import into the model.
After importing, the model provides a message that states “Batch import
successful! 0 records imported.”
13 References
191
Answer:
First, open the .csv file to make sure it looks correct and is the proper version
(v1.19). The company may not have exported it correctly on its end. Instructions
on how to export model runs are found on page 40 of the user guide.
If the .csv looks correct, the company may have accidentally saved it as an Excel
file. Once a model run is exported, changes cannot be made to it. If you open the
.csv, change something (or not), and then press “Save,” Excel will automatically
change it to Excel format. Even though the suffix is still .csv, it is actually now an
Excel file. The only way to make changes to a .csv file is to import it back into the
model, make changes on the input page, and then reexport it.
Issue: MOP input values.
Should the MOP values be for a sustained rate or should they include very short
duration high pressure anomalies?
Answer:
The intent of the program is to calculate EPZs based on normal operating
conditions, not anomalous or maintenance conditions. Therefore, all values
entered should be reflective of normal operating conditions.
Issue: Companies want to use values lower than the default in the model.
There are cases where companies want to use values that are lower than the
default. Specifically, they would like to use lower than 10 % for the low pressure
trigger.
Answer:
The defaults in the model are there as safety measures; therefore, even if a
company enters a lower value, the model will default to the higher number. If the
company feels that the default is unreasonable, it can send feedback to
[email protected], and ERCB staff will look at it for future model
revisions.
In the case of wanting a low pressure trigger less than 10 %, this number is
already so low that it means the line will be virtually depressured before the ESDs
close. If the company would like to use a lower value, it should choose “No
Mitigation” instead.
Issue: Gas lift wells.
Answer:
13
192
Gas lift wells must be entered into the model using the release rate and H2S when
the lift is operating.
Issue: Wells that are “suspended” but do not meet the requirements of
Directive 013.
Answer:
As these wells have not been suspended in accordance with Directive 013,
companies must use the last available flow rate and gas analysis to calculate an
EPZ.
Issue: CO2 modelling
Does the model take into account hazards associated with CO2?
Answer:
The model does have an input for CO2; however, it is meant to create an EPZ for
hazards associated with H2S only. If a company wishes to create a corporate-level
plan to deal with CO2 hazards, it will have to do its own modelling to determine
an EPZ.
Issue: Setback designation on summary page.
Why does the setback level sometimes indicate N/A?
Answer:
Setbacks only apply to sour gas pipelines with greater than 1 % H2S, not natural
gas pipelines. For model runs less that 1 %, N/A appears.
Issue: Different EPZ sizes for drilling and completions.
Applicants run the model for both drilling and completions and get different
results. Which .csv should be submitted with the ERP? Which EPZ should be
used for the ERP?
Answer:
If it is a drilling and completions ERP, it must be based on the larger EPZ of the
two operations. The .csv for the larger operation must be submitted along with the
ERP.
Issue: The EPZ on the Directive 056 application is for production. Does that
mean the ERP should be based on that EPZ?
13 References
193
Directive 056 requires that companies input the EPZ for the largest of (a) drilling,
(b) completions/servicing, or (c) producing/suspended in the Schedule 4.3
application. In some cases, the largest EPZ will be associated with production.
Answer:
Though Directive 056 requires notification to be based on the largest zone,
Directive 071 requirements are for drilling/completions only. Therefore, the
ERCB does not expect a company’s drilling/completions plan to be based on a
production EPZ, nor does it expect applicants to do their Directive 071
consultation out to the estimated production EPZ. The applicant will have to
provide an explanation of why the EPZ in the application does not match that in
the ERP.
Issue: What is the largest EPZ that the model will calculate?
Answer:
The largest EPZ the model will calculate is 30 km. Companies can change their
operating procedures to try to reduce this value. Using mitigation, especially in
populated areas, is strongly recommended. In remote areas, companies will have
to do an analysis of whether the benefits of a reduced planning zone outweigh the
costs of additional mitigation.
Issue: What release rate/release volume from the model should be used for
the Directive 056 application?
There are several different release rates/release volumes in the model. Which one
is the correct one to use for the licence application?
Answer:
The Land Use Setback and OLD EPZ H2S Release Rate or Volume at Licensed
Conditions in column DV on the batch sheets is the number that should be used.
Issue: Low-end cut-off point for EPZ sizes.
In the old directive, there was a low-end cut off for EPZ sized. For example, if the
H2S RR was below 0.01m3/s H2S, the only requirement was for a corporate ERP
(and the EPZ was 0 km as the release was likely contained on lease). In the new
Directive 071, it is not clear if the minimum criteria still exists.
Answer:
At this point, there is no low-end cut off other than those referred to in Directive
071. The ERCB recognizes that there are concerns around this issue and that a
process will need to be created to deal with it. However, until this issue is dealt
13 References
194
with through the implementation plan (in July 2009), all EPZs are valid,
regardless of size.
Issue: Expected maximum liquid flow rate of pipeline fluid.
The expected maximum liquid flow rate influences the EPZ size for the
GLR<1000 model and companies are concerned that it may be difficult to derive
this value for a complex system.
Answer:
The operator should have this information available based on production
accounting. For example, if well A is assigned flow A and well B assigned flow
B, then the pipeline that is joined to each well is modelled with flows A and B
respectively. At the tie-in of the two lines, the flow would just be A + B.
To be conservative, one could use the total cumulative flow rate at the discharge
of the gathering system for each pipeline segment in the system. For example:
Well 1 is producing 10 m3/d of oil, 5 m3/d of water, and 50 m3/d of gas
Well 2 is producing 20 m3/d of oil, 10 m3/d of water, and 50 m3/d of gas
Flow 1 = 15 m3/d
Flow 2 = 30 m3/d
Flow 3 (combined 2 & 3) = 45 m3/d
So the GLR inputs are:
Well 1 GLR = 50/15
Well 2 GLR = 50/30
Combined GLR = (50 + 50)/(15 + 30) = 100/45
Issue: Pipelines with larger H2S concentrations giving EPZs smaller than
pipelines with smaller H2S concentrations.
All other things being equal, why would a pipeline with 60 % H2S give a smaller
EPZ than one with 20 % H2S?
Answer:
The reason for this centres around buoyancy. Basically, the more H2S in a
mixture, the denser it is and the less buoyant it is. Therefore, the gas would have
the tendency to spread out over an area rather than disperse horizontally. In very
basic terms, with 55 % H2S your plume would be more circular, with 20 % H2S it
would be long and skinny.
13 References
195
Issue: New pipeline tying into an existing system. Is recalculation of the
system required?
Answer:
When the directive was released, the ERCB stated that for well supplements or
pipeline tie-in, the new operation has to be modelled and that EPZ adopted. The
existing pipelines don't have to be modelled and the ERP does not have to be
rewritten. Therefore, the ERCB does not require that the entire system be
recalculated unless there is a significant change to the H2S or release volume.
However, should a company choose to remodel the entire system (the ERCB
always encourages being proactive), then it would have to complete its
notification in accordance with the directive. This may result in a review and
variance (R&V) application from local residents, which would be dealt with by
the ERCB Law Branch.
13 References
196
13.
References
Energy Resources Conservation Board (ERCB). 2010. ERCBH2S A Model for
Calculating Emergency Response and Planning Zones for Sour Gas
Facilities. Volume 2: Emergency Response Planning Endpoints.
http://www.ercb.ca/docs/public/sourgas/eubmodelsdraft/Volume2_ERPEndPoints.pdf
Energy Resources Conservation Board (ERCB). 2010. ERCBH2S A Model for
Calculating Emergency Response and Planning Zones for Sour Gas
Facilities. Volume 1: Technical Reference Document Version 1.20.
http://www.ercb.ca/docs/public/sourgas/eubmodelsdraft/Volume1_TechnicalReference.pdf
Energy Resources Conservation Board (ERCB). 2008. Directive 071–
Emergency Preparedness and Response Requirements for the Petroleum
Industry.
http://www.ercb.ca/docs/documents/directives/Directive071_draft_200712.pdf
13 References
197
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement