COMMENTS RESOLUTION SHEET (CRS)
PROJECT NUMBER
EE 6062
TRANSMITTAL REFERENCE, DATED:
EDP-ELE-CON-TRN-0005, Dated - 26/12/2023
DOCUMENT NUMBER, REV & TITLE:
EE-6062-TS-AR-0001, Rev 01, GAS DETECTION STUDY ASSUMPTION
REGISTER
Sr.
No
Reviewer
Section
COMMENTS
Response
1
Farid.Intisar
List of Abbreviations
GDZ
Noted and updated as GDZ in the Rev-02 AR
2
Farid.Intisar
List of Abbreviations
GTH term is no longer being used. Instead SGPC to be used in place of GTH
Noted and SGPC term is used in place of GTH
Delete Ghazij
3
Farid.Intisar
1.1
Noted and updated
Use only HRL
4
Farid.Intisar
1.1.1.1
5
Farid.Intisar
1.1.2
6
Farid.Intisar
1.1.2
7
Farid.Intisar
1.1.2
8
Farid.Intisar
1.1.2
9
Farid.Intisar
1.1.2
10
Farid.Intisar
1.1.2
11
Farid.Intisar
1.1.2
12
Farid.Intisar
1.1.2
13
14
15
16
17
18
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
1.1.2
1.1.2.1
1.1.2.1
1.1.2.1
1.1.2.1
1.1.2.1
19
Farid.Intisar
1.1.2.1
20
21
22
23
24
25
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
1.1.3.1
1.1.3.1
1.1.3.1
1.1.4
1.1.4
1.1.4
through Tipu Sales Gas Metering (01-SGM-0301). The metered sales gas is blended with processed
gas from Goru Trains and metered again through Co-mingled Sales Gas Meter (01-SGM-0302).
Hydrocarbon liquid / condensate from inlet separator is sent to condensate degasser (01-V-1201)
Noted and updated the AR accordingly
and then to condensate storage tanks.
Produced water from Inlet separator is sento PW Degasser (01-V-1801) and then to ponds through
CPI
Add Raw Gas Meters
01-RGM-0103A/B
02-RGM-0103A/B
01-V-0101A/B
02-V-0101A/B
01-M-1003A/B.
02-M-1003A/B
01-M-1001A//B/C
02-M-1001A/B/C
ASU Tags:
01-ASU-0101
02-ASU-0101
01-ASU-0201
01-DHU-0101
02-DHU-0101
01-DHU-0101
02-DHU-0101
01-HOP-701
02-HOP-701
Co-mingled sales meter (01-SGM-0302)
via pre-treatment skid(s)
01-ASU-0101 / 02-ASU-0101 / 01-ASU-0201
units
units
0101-DHU-0101 / 02-DHU-0101)
The gas is blended with processed gas from Tipu Train and metered through Co-mingled Sales Gas
Meter (01-SGM-0302).
Hydrocarbon liquid / condensate from inlet separator is sent to condensate degasser (01-V-1201)
and then to condensate storage tanks.
Produced water from Inlet separator is sento PW Degasser (01-V-1801) and then to ponds through
CPI
of
upstream of Goru Membranes Pre-Treatment skid(s)
upstream of ASU
Condensate storage and dispatch system
Already covered in process description
RO Unit system
Page 1 of 3
Noted and added in the updated AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted added in the AR, Refer Rev-02 AR
Noted and updated the AR accordingly
Noted and added in the Rev-02 AR
Noted and added all the amine gas sweetening units in the AR
Noted and updated the AR accordingly
Noted and updated the AR accordingly
Noted and added in the Rev-02 AR
Noted and updated the AR accordingly
Noted and updated the AR accordingly
Noted and added in the Rev-02 AR
Noted and added in the Rev-02 AR
Noted and added in the Rev-02 AR
Noted and removed from the AR
Noted and added RO unit system in the AR
REMARKS
COMMENTS RESOLUTION SHEET (CRS)
PROJECT NUMBER
EE 6062
TRANSMITTAL REFERENCE, DATED:
EDP-ELE-CON-TRN-0005, Dated - 26/12/2023
DOCUMENT NUMBER, REV & TITLE:
EE-6062-TS-AR-0001, Rev 01, GAS DETECTION STUDY ASSUMPTION
REGISTER
Sr.
No
Reviewer
Section
26
27
Farid.Intisar
Farid.Intisar
1.2
1.2
28
Farid.Intisar
1.2
COMMENTS
Response
HRL in itself is not a unit
Is flare & vent being considered for GDs
Missing Units:
1. Raw Gas Meter
2. Amine Sweeting Units
3. Dehydration Units
4. Recycle & Booster Compressors
5. Sales Metering
6. Condensate & Produced Water Degassers
7. CPI Pit & Slop Vessel
8. Hot Oil Circuit
9. Power GenSets & E-House
Noted and updated the AR accordingly
Noted and updated the AR accordingly
Noted and added the missing units in the AR
29
Farid.Intisar
2.2
Pls mention relevant excrept from the DEP utilizied in the study as an annexure to the AR
The reference has been duly provided in both the AR (Assessment Report) and the
Gas Detection Philosophy documentation. Replicating entire standards or guidelines
within the project documents is not considered a best practice. Instead, it is
recommended to consult the standard document directly by referring to the provided
reference notes.
30
Farid.Intisar
2.2
During weekly review meeting, Elixir has indicated that BP standards/practices are also available.
Pls refer to it here as well
Noted and added in the Rev-02 AR
31
Farid.Intisar
3
installed
Noted and updated the AR accordingly
32
Farid.Intisar
4
For MPC: order of preference is:
33
34
Farid.Intisar
Farid.Intisar
4
4
LCD or DCS or ESD
Blue
36
Farid.Intisar
4
Do we really required beacon and alarm in field for 1ooN alarm?
Farid.Intisar
4
Blue
Refer to Shell / BP DEP or Recommended Practices for action in case of 2ooN.
37
Farid.Intisar
4
In Annexure::
Pls mention full clause including the part related to provision of eliminating Trip subject Risk
Assessment by owner owner / operator
38
Farid.Intisar
4
Pls add Elixir recommendation as well based on recognized Recommendation Practices
39
Farid.Intisar
5
40
Farid.Intisar
5
41
Farid.Intisar
5
Personnel, Environment, Asset(s) and Reputation
Is this being done by Elixir or some existing study shall be used? Pls refer to relevant study in
section / step
Pls elaborate on characterization (Basis for severity and frequency)
Pls add explanation for Fire Zone
Noted and updated the AR according to the MPC preferences
Noted and added in the Rev-02 AR
Noted and added in the Rev-02 AR
Yes if it is a high level of alarm it reqired. Refer Gas detection philosophy document
for detail response table.
Noted and added in the Rev-02 AR
It is a summary table with the reference of gas detection philosophy document, for
detail the reference note has been provided to refer Gas detection philosophy.
Recommendations inline with the standards are provided in the Gas detection
philosophy.
Noted and updated in the methodology, refer updated assumption register.
Noted and updated in the methodology, refer updated assumption register.
Not applicable for Gas detection study, Hence it is removed.
Also refer to the practices considered
Pls add in explanation of Risk Volume and Cloud Charatieristics
42
Farid.Intisar
5
Noted and updated in the methodology, refer updated assumption register.
Refer to clause of standard being considered. Document detailed clause in annexure as well
Initial assessment shall be done based on existing installed detectors.
43
44
45
46
47
48
49
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
5
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
In case of limitation, additional detectors to be considered.
Noted and updated in the methodology, refer updated assumption register.
Coverage for existing installed detectors as well as with additional detectors to be shared
Add in criteria for Gas Detection Zones classifications
Add Area Title - Inlet Manifold Area
Add Area Title - Separators & Raw Gas Metering
Add Area Title - Sales Gas Metering
Add Area Title - Tipu Compressors Area
Add Area Title - Tipu Process Plant
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Page 2 of 3
REMARKS
COMMENTS RESOLUTION SHEET (CRS)
PROJECT NUMBER
EE 6062
TRANSMITTAL REFERENCE, DATED:
EDP-ELE-CON-TRN-0005, Dated - 26/12/2023
DOCUMENT NUMBER, REV & TITLE:
EE-6062-TS-AR-0001, Rev 01, GAS DETECTION STUDY ASSUMPTION
REGISTER
Sr.
No
Reviewer
Section
COMMENTS
50
51
52
53
54
55
56
57
58
59
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
Farid.Intisar
60
Farid.Intisar
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 1
7. Assumption No. 2
7. Assumption No. 3
7. Assumption No. 1
Add Area Title - Goru Membranes
Add Area Title - Goru/Tipu Pre-Heaters
Add Area Title - Amine Sweeting Units
Add Area Title - Dehydration Units
Add Area Title - ASU Hot Oil Heaters
Add Area Title - HRL Compressor Areas
Add Area Title - Flare Area
Add Area Title - Condensate Stabilization & Storage
Add Area Title - Condensate Disptach
Add Area Title - Fuel Gas
2nd stage Guard Bed
2nd stage Filter Coalescer
Condensate Loading Gantry
61
Farid.Intisar
7. Assumption No. 3
What will be the value use for trip actuation? 10% or 40%
Response
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and added the area title in the AR
Noted and updated the AR accordingly
Noted and updated the AR accordingly
Noted and updated the AR accordingly
40% LFL with 2ooN voting confirmation. Refer Gas detection philosophy document
for detail response table.
Regarding the interpretation of '2 LFL-m,' it signifies a combination of the
concentration of hydrocarbon (HC) gas, measured in terms of the lower flammable
limit (LFL %), and the distance of the gas cloud. Specifically, it not only imply
achieving 100% LFL in a 2-meter cloud or 200% LEL in a 1-meter cloud. Instead, it is
calculated by multiplying the LFL percentage by the distance the cloud extends. For
example, if a 50% LFL cloud extends up to 4 meters, it would be defined as 50% * 4
= 2 LFL-m. Therefore, '2 LFL-m' is a metric that takes both gas concentration and
cloud distance into account.
Pls confirm that 2 LFL-m interpretation?
62
Farid.Intisar
7. Assumption No. 3
Doe it mean 100% LEL achieved in 2 meter cloud?
Or 200% LEL in 1 meter cloud?
63
Farid.Intisar
9
Is there any requirement for GD to be considered for Loading Gantry?
64
Farid.Intisar
9
Pls add / mark GDZ for future FEC Compressors?
.Only 2 x GDUs are installed.
65
Farid.Intisar
9
Understanding the nature of the gantry area where flammable gases are likely to be
present during loading activities, we acknowledge the concern about continuous
spurious alarms that may be triggered by gas detectors. In light of this, and
considering the specific conditions in the area, the decision has been made to avoid
gas detection in this zone and instead prioritize the use of fire detection systems.
Noted and added.
Noted, and the gas detection will not be assessed for 6.3 eventhough it is availabile
in the 3D model.
GDU marked as 6.3 is not installed, nor planned to be installed
Gas Gensets and MCCs has not been marked in zoning.
66
Farid.Intisar
As per the confirmation from the MPCL, these gensets are being operated by fuel
gas. Hence it is also considered as separate Gas detection zone.
9
Pls confirm justification for not considering it
67
Farid.Intisar
9
PW Deagg=asser - is there any requirement to provide GD here?
68
Farid.Intisar
9
Pls confirm if slop vessel and CPI to be included in GD zone?
69
Farid.Intisar
9
Is there any requirement to consider flare KOD as a GD zone?
70
Farid.Intisar
Mail
Refering to the HMB data (Hysys model data), the Methane percentage in the
streams are negligible. Therefore, the installation of a Gas Detector (GD) is not
recommended.
Refering to the HMB data (Hysys model data), the Methane percentage in the
streams are negligible. Therefore, the installation of a Gas Detector (GD) is not
recommended.
Taking into account the current conditions on site and after discussing with MPCL,
the decision has been made to refrain from implementing gas detection in the KOD
area. Instead, the emphasis is placed on prioritizing the utilization of fire detection
systems in this particular location.
Is methane LEL of 5% is counted as 1 LEL, what would be methane concentration for proposed 1
LEL-m or 2 LEL-m set points?
Page 3 of 3
Refer response # 62.
REMARKS
Gas detection study
Assumption register
Gas Detectors Zoning Study
For
Sachal Gas Processing
Complex
Gas detection study
Assumption register
DOCUMENT DETAILS
Elixir
Engineering
Project No.:
EE 6062
DOCUMENT APPROVAL FORM
Client:
MARI PETROLEUM COMPANY LIMITED
Report Title:
GAS DETECTION STUDY ASSUMPTION REGISTER
Document No: EE-6062-TS-AR-0001
Rev No. 02
SIGNATURE
Date
Prepared by:
Thirunavukkarasu
21-01-2024
Reviewed by:
Vinod
21-01-2024
Approved by:
Vinod
21-01-2024
REVISIONS
Rev No.
01
02
Description
Issued for
Comment
Issued for
Approval
By
Reviewed
Approved
Date
TA
RPM
RPM
21-12-2023
TA
VP
VP
21-01-2024
CLIENT APPROVAL OF TECHNICAL QUERY:
Rev No.
Name & designation
Signature
Date
This document is confidential and has been produced for the purpose of the abovementioned study and is only suitable for use in connection therewith.
Any liability arising out of use of this document by the above-mentioned client or third
party, for purposes not wholly connected with the above-mentioned study, shall be the
responsibility of the above-mentioned client who shall indemnify Elixir Engineering
against all claims, damages and losses arising out of such use.
Page | 2
Gas detection study
Assumption register
TABLE OF CONTENTS
1
INTRODUCTION ................................................................................................................... 6
1.1
FACILITY DESCRIPTION ................................................................................................................... 6
1.1.1
GAS PROCESS FACILITY FOR TIPU ............................................................................................................................ 6
1.1.2
GAS PROCESS FACILITY FOR GORU .......................................................................................................................... 7
1.1.3
GAS PROCESS FACILITY FOR HRL/GHAZI ............................................................................................................. 8
1.1.4
OTHER FACILITIES ........................................................................................................................................................... 9
1.2
SCOPE ..................................................................................................................................................... 10
2
CODES AND STANDARDS ................................................................................................ 11
2.1
INTERNATIONAL CODES AND STANDARDS ........................................................................ 11
2.2
RECOMMENDED PRACTICES....................................................................................................... 11
3
STUDY OBJECTIVE ............................................................................................................. 12
4
GAS DETECTION ................................................................................................................. 12
5
METHODOLOGY ................................................................................................................. 14
6
SOFTWARE USED ............................................................................................................... 16
7
KEY ASSUMPTIONS ........................................................................................................... 17
8
REFERENCES........................................................................................................................ 25
9
APPENDICES ........................................................................................................................ 26
Page | 3
Gas detection study
Assumption register
LIST OF FIGURES
Figure 1 - Schematic Diagram of SGPC Facility..................................................................................... 6
Figure 2 – Gas Detection study Methodology ...................................................................................... 15
LIST OF TABLES
Table 1 - List Of Units..................................................................................................................................... 10
Table 2 – Table of response for gas detection..................................................................................... 12
Page | 4
Gas detection study
Assumption register
LIST OF ABBREVIATIONS
1ooN
2ooN
CCR
ESD
FZ
GDZ
H 2S
IR
IRGD
LEL
LFL
MMSCFD
MPCL
P&ID
PFD
SGPC
One out of (1oo) the number (N) of detectors
Two out of (2oo) the number (N) of detectors
Central Control Room
Emergency Shutdown
Fire Zone
Gas Detection Zone
Hydrogen sulphide
Infrared
Infrared Gas Detectors
Lower Explosive Limit
Lower Flammability Limit
Million Standard Cubic Feet Per Day
Mari Petroleum Company Limited
Process and Instrumentation Diagram
Process Flow Diagram
Sachal Gas Processing Complex
Page | 5
Gas detection study
Assumption register
1 INTRODUCTION
1.1 FACILITY DESCRIPTION
SGPC facility comprises of two (2) processing facilities:
FIGURE 1 - SCHEMATIC DIAGRAM OF SGPC FACILITY
1.1.1 GAS PROCESS FACILITY FOR TIPU
Tipu gas process facility comprises of:
•
•
•
•
•
Tipu Inlet Manifold / Pig Receiver (01-R-0401)
Tipu Inlet Separator (01-V-0001)
Raw Gas Metering (01-RGM-0102)
Tipu 2 Stage Membrane (01-MR-0001)
o Booster Compressor (01-C-0001A/B/C/D)
o Recycle Gas Compressor (01-C-0002A/B)
Sales Gas Metering (01-SGM-0301)
Page | 6
Gas detection study
Assumption register
1.1.1.1 Tipu Operational Philosophy
Well fluid (multiphase) from Tipu 1&2 wellheads are introduced to a three phase inlet
separator (01-V-0001). The HP raw gas stream from the inlet separator is measured
through Raw Gas Metering (01-RGM-0102) unit and then sent to the Gas sweetening 2Stage Membrane Unit (01-MR-0001), sales gas from 2-stage membrane is metered
through Tipu Sales Gas Metering (01-SGM-0301). The metered sales is blended with
processed gas from Goru Trains and again metered through Co-mingled Sales Gas
Meter(01-SGM-0302). Hydrocarbon liquid / Condensate from inlet separator is sent to
condensate storage tanks.
Produced water from inlet separator is sent to PW Degasser (01-V-1801) and then to
ponds through CPI.
1.1.2 GAS PROCESS FACILITY FOR GORU
Goru gas process facility comprises of two (2) identical process trains (01/02), each train
comprise of:
•
•
•
•
•
•
•
•
Goru Inlet Manifold (01-MF-0101)/ Pig Receiver (01-R-0402); common for both
Trains
Raw Gas Meters
01-RGM-0103 A/B
02-RGM-0103 A/B
Goru Separators
01-V-0101A/B
02-V-0101A/B
Single Stage Membrane
01-MR-0101A/B
02-MR-0101A/B
Pre-Treatment (Water Bath Heater, Filter Coalescer, Dust Filter and Guard Bed)
01-M-1001A/B/C
02-M-1001A/B/C
3 x Water Bath Heaters for two trains (2 in service + 1 on standby)
Amine Sweetening Unit
01-ASU-0101
02-ASU-0101
01-ASU-0201
Glycol Dehydration Unit
01-DHU-0101
Page | 7
Gas detection study
Assumption register
•
•
02-DHU-0101
Hot Oil System
01-HOP-0701
02-HOP-0701
Co-mingled sales Meter
01-SGM-0302
1.1.2.1 Goru Operational Philosophy
Both Goru processing trains are identical therefore Operating philosophy for both trains
are similar.
Well fluid (multiphase) from Goru wellheads are introduced to a three phase inlet
separator (01-V-0101A/B). The HP raw gas stream from the inlet separators (01V- 0101A/B) is introduced to the Single Stage Membrane Units (01-MR-0101A/B)
via pre-treatment skid(s), which lowers the CO2 content of raw gas. Gas from
membrane unit is further processed by amine sweetening units (01-ASU0101/02-ASU-0101/01-ASU-0201) and then introduced to Glycol dehydration
units (01- DHU-0101/02- DHU-0101) for removal of water content from gas. The
Gas is blended with processed gas from Tipu Train and metered through Comingled sales Gas Meter (01-SGM-0302).
Hydrocarbon liquid / Condensate from inlet separator is sent to Condensate
degasser (01-V-1201) and then to condensate storage tanks.
Produced water from inlet separator is sent to PW degasser (01-V-1801) and then
to ponds through CPI.
Note: Goru Tipu jump over is available to process Tipu Wells Gas in Goru Processing and vice
versa.
1.1.3 GAS PROCESS FACILITY FOR HRL/GHAZI
HRL gas process facility comprises of:
•
•
•
•
•
Goru Inlet Manifold (01-MF-0201)/ Pig Receiver (01-R-0403)
Inlet Separator
HRL Front End Compressors (01-C-0201A/B)
HRL Compressor After Separator (01-V-0201)
HRL Raw Gas Metering (01-RGM-0201)
Page | 8
Gas detection study
Assumption register
1.1.3.1 HRL Operational Philosophy
Gas from HRL wells is introduced to a three phase inlet separator. The raw gas stream
from the inlet separators is compressed in Compressors and then introduced to
Compressor After Separator (01-V-0201). Gas from after separator is measured by raw
gas metering (01-RGM-0201) and can then be lined up either to upstream of Goru
Membranes Pretreatment skid(s) or sent directly to upstream of ASU for onward
processing and sales.
1.1.4 OTHER FACILITIES
The listed facilities are available at SGPC facility,
•
•
•
•
•
•
•
•
•
•
Fuel Gas Package
Flare System
Hot Oil Systems
Condensate Storage and Dispatch System
Compressed Air System
Nitrogen Generation Package
Raw Water System
Fire Water Network
DCS Process Control & ESD System
RO Unit System
Page | 9
Gas detection study
Assumption register
1.2 SCOPE
This philosophy specifies requirements and gives recommendations for the type
selection, specification and installation of gas detection systems (GDSs) for the project
scope of facilities.
The following tables shows the unit considering for the Gas Detection study,
TABLE 1 - LIST OF UNITS
Unit No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
UNIT DESCRIPTION
MANIFOLDS
INLET SEPERATOR AREA
METERING
TIPU UOP 2 STAGE MEMBRANE AREA
GORU-B SINGLE STAGE MEMBRANE
HRL
FEC & SALES GAS COMPRESSORS AREA
FLARE & VENT
CONDENSATE STORAGE & LOADING GANTRY
UTILITY AREA
RAW GAS METER
AMINE SWEETING UNITS
DEHYDRATION UNITS
RECYCLE & BOOSTER COMPRESSORS
SALES METERING
CONDENSATE & PRODUCED WATER DEGASSERS
CPI PIT & SLOP VESSEL
HOT OIL CIRCUIT
POWER GENSETS & E- HOUSE
Page | 10
Gas detection study
Assumption register
2 CODES AND STANDARDS
2.1 INTERNATIONAL CODES AND STANDARDS
Codes / Standards
Description
ISA-TR84.00.07
Guidance on the Evaluation of Fire, Combustible Gas, and
Toxic Gas System Effectiveness -2018
2.2 RECOMMENDED PRACTICES
Codes / Standards
Description
DEP 32.30.20.11-Gen
SHELL DEP - FIRE, GAS AND SMOKE DETECTION SYSTEMS
BP GP. 30-85
GUIDANCE ON PRACTICE FOR FIRE AND GAS DETECTION
Page | 11
Gas detection study
Assumption register
3 STUDY OBJECTIVE
The objective of the Gas detection study is to ensure gas detectors are installed in line
with the gas detection Philosophy of Project based on Gas Detector Layouts, identify any
gaps based on the Gas detection study and to make recommendations where required
on the numbers and placement of the various detectors.
4 GAS DETECTION
Prompt detection of gas release at its earliest stage of development is a crucial factor for
fire protection systems to be effective, with a rapid response minimizing the potential
for the event to escalate. A good fire & gas detection system gives detection provisions
aligned with the hazards present across the facility, providing a response that minimizes
the impact of releases to Personnel, Environment, Asset(s), and Reputation. Detection
can take place by personnel or by safeguarding instruments, with instrument detection
systems including the following:
•
Manual Call Point, which provides a warning signal by personnel
•
Gas detection, which provides warning of gas leaks. (Flammable)
As per the facility Gas Detection Philosophy (EE-6062-TS-PY-0001), the nature of the
response is defined in below,
TABLE 2 – SUMMARY TABLE OF RESPONSE FOR GAS DETECTION
Detection
Flammable
Gas
Response for 1ooN
Response for 2ooN
1. A common audible alarm 1. A common audible alarm and a
and a visual alarm in the
visual alarm in the control Room.
control Room
2. Confirmed flammable gas audible
2. Audible and visual alarm
alarm and a visual alarm display
(Blue flashing beacons) in
on LCD or DCS or ESD screen in
the
concerned
Gas
the Central Control Room (CCR).
Detection zone
3. Audible and visual alarm (Blue
flashing
beacons)
in
the
concerned Gas Detection zone.
4. Activation of ESD-1.
Page | 12
Gas detection study
Assumption register
Notes:
1. As per Shutdown philosophy of MPCL (0503223-PRO-RP-0011_A), ESD- 1
refers Total Plant shutdown with Depressurization.
2. For detail refer response table refer Table 4 in the Gas detection Philosophy
document (EE-6062-TS-PY-0001).
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5 METHODOLOGY
The stepwise procedure is given below:
Step 1: Hazardous Area Identification
The Sachal Gas Processing Complex will undergo a comprehensive desktop assessment
to identify hazardous areas with flammable gas hazards, and these areas will be
segregated into different hazardous detection or mapping areas based on the facility
plot plan and process simulation report.
Step 2: Hazardous Area Characterization
Based on the aforementioned identification, a desktop study will be conducted to
characterize major accident hazards, considering fluid properties and release quantities
using PIDs and the Process Simulation Report. Additionally, areas prone to flammable
gas accumulation will be characterized as open, congested, or confined, utilizing the plot
plan and 3D model.
Step 3: Determination of Risk Volume / characteristic cloud for detection
Risk volume is characterized as the volume within which the accumulation of
hydrocarbon gas may result in a potential explosion or flash fire, causing significant
harm to personnel and assets. Typically, it is determined based on the guidelines
outlined in Shell DEP 32.30.20.11, considering the area characterization, such as open,
congested, or confined, and is often expressed in terms of diameter.
Step 4: Detect 3D Modelling.
The 3D Geometry file will be imported to the software and the Gas detectors will be
placed based on preliminary Gas detector Layout at the hazardous zone.
Step 6: Coverage Mapping
The preliminary evaluation of coverage to achieve the specified target will be conducted
by utilizing the existing detectors position. If any limitations are identified, further steps
will be taken, including the installation of new detectors or relocating existing ones, to
ensure that the detectors are appropriately positioned to sense and detect potential gas
dispersion in that area.
Step 6: Optimization/Detector Layout Definition
Repeat the above steps for all loss of containment scenarios. Optimize the detector
location height or change the place of the detector location to match the dispersion
coverage of the hydrocarbon release if the detectors are found inadequate to sense or
detect the dispersion.
The methodology for gas detector mapping have been indicated in the flow chart below;
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Hazardous Area
Identification
Detect 3D
Modeling/ Placing
Detectors
Hazardous Area
Characterization
Check Coverage
Results
Gas Detection Zone
Risk Volume Definition
Optimization/
Detector Layout
Target Not meet /
Largely Exceeded
Yes
Yes / No
No
END (Modelling)
FIGURE 2 – GAS DETECTION STUDY METHODOLOGY
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6 SOFTWARE USED
Detect 3D 2.54 Software will be used for this Gas Detection study.
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Gas detection study
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7 KEY ASSUMPTIONS
The list of Assumptions made for 3D F&G Mapping Study are provided below.
Assumption No.
Assumption Description
1.
Gas Detection Zone
2.
Detectors characteristics
4.
Flammable Gas Detection – Detection Range, Alarm Set Point,
Elevation, Voting logic
Gas Detection- Risk Volume/Cloud Size
5.
Result presentation of 3-D Coverage
3.
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ASSUMPTION SHEET
01
Revision:
02F
Assumption No.:
Subject:
Date:
21-01-2024
Gas Detection Zone
Assumption:
Criteria for Gas Detection Zone classifications and their requirement of Detectors in line
with Gas detection Philosophy,
Gas Detection
Zone
GDZ-101-1
Inlet Manifold
Area
GDZ-102-1
Separators &
Raw Gas
Metering
GDZ-103-1
Sales Gas
Metering
GDZ-104-1
Tipu
Compressors
Area
GDZ-104-2
Tipu Process
Plants
Unit No.
Facility / Equipment description
1.1
Goru B
1.2
2.1
2.2
2.3
5.4
6.1
10.35
4.19
3.1
3.3
10.34
Tipu
Goru B
Tipu
HRL
(Goru-B) RAW GAS METERING
(HRL) RAW GAS METERING
ANALYZER FOR RAW GAS METERING
(TIPU) RAW GAS METERING
TIPU SALES GAS METERING
GORU-B SALES GAS METERING CO- MINGLED
ANALYZER FOR SALES GAS METERING
4.15
BOOSTER COMPRESSORS
4.16
TIPU RECYCLE COMPRESSORS
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
10.32
4.10
4.11
4.12
4.13
4.14
4.20
4.21
FIRST STAGE MEMBRANE, SKID 1
SECOND STAGE MEMBRANE, SKID 2
GAS EXCHANGER
FILTER COALESCER
GUARD BED
PARTICLE FILTER
REGENERATION GAS COOLER
REGENERATION GAS SEPARATOR
CONDENSATE HEATER
ANALYZER FOR TWO STAGE MEMBRANE
CONDENSATE FLASH TANK
MEMGUARD ADSORBER WITH VALVE SKID
REGENERATION GAS BLOWER
FILTER COALESCER
PARTICLE FILTER (A/B)
2 STAGE FILTER COALESCER
2 STAGE GUARD BED
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GDZ-105-1
Goru
Membranes
GDZ-105-2
Goru /Tipu
Pre-Heaters
GDZ-105-3
A/B/C
Amine
Sweeting Units
GDZ-105-4
Dehydration
Units
GDZ-105-5
ASU Hot Oil
Heaters
GDZ-106-1
HRL
Compressors
Areas
5.1
5.2
10.33
5.6
4.17
4.18
SINGLE STAGE MEMBRANE
PRE-TREATMENT
ANALYZER FOR SINGLE STAGE MEMBRANE
PREHEATER SKID
RE-GENERATION GAS HEATER
MEMBRANE PREHEATER
5.3
AMINE UNIT - 1 /2
6.6
AMINE UNIT - 3
5.5
DEHYDRATION SKID
5.7
Goru-B HOT OIL HEATER SKID
6.2
HRL COMPRESSORS
GDZ-107-1
FEC area
7.1
FEC AREA
7.2
SALES GAS COMPRESSORS
GDZ-109-1
Condensate
Stabilization &
Storage
9.1
CONDENSATE DEGASSER SKID
9.2
CONDENSATE STORAGE TANK
9.3
CONDENSATE LOADING PUMP
10.3
FUEL GAS SKID
10.22
GAS GENSET
10.23
MCC ROOM
GDZ-110-1
Fuel Gas
GDZ-110-2
Genset & MCC
area
Refer Appendix-1 for Gas Detection Zone Layout.
References:
1. Gas Detection Philosophy (EE-6062-TS-PY-0001)
Comments:
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Gas detection study
Assumption register
ASSUMPTION SHEET
02
Revision:
02F
Assumption No.:
Subject:
Date:
21-01-2024
Detectors characteristics
Assumption:
ASSUMPTION SHEET
Flammable Gas detector:
Types:
HC gas Detector – Open path type [Infrared (IR)]
HC gas Detector – Point type [Infrared (IR)]
References:
1. Gas Detection Philosophy (EE-6062-TS-PY-0001)
Comments:
Page | 20
Gas detection study
Assumption register
ASSUMPTION SHEET
03
Revision:
2F
Assumption No.:
Subject:
Date:
21-01-2024
Flammable Gas Detection – Detection Range, Alarm Set Point,
Elevation, Voting logic
Assumption:
Flammable Gas Detection
Detection Range
The detection range of the flammable gas detectors follows,
SI.
No
Type
1
2
Sensing
Element
Detection
Range
(Meter)
Sensitivity
Range
HC gas Detector – Open Infrared (IR)
Path type
15-100
0-5 LFL. m
HC gas Detector –Point Infrared (IR)
type
-
0-100% LFL
Note: Sensitivity for Open Path Detector shall be calculated using this formula, % of LFL
x Cloud width (m). (ie., 20% LFL x 5-meter cloud wide = 1 LFL. m)
Alarm Set Point for Point type Detector
The Alarm set point of the Point type flammable gas detectors is
•
Low Alarm at 10% LFL
•
High Alarm at 40% LFL
Alarm Set Point for Open path type Detector
The Alarm set point of the Point type flammable gas detectors is
•
Low Alarm at 1 LFL.m
•
High Alarm at 2 LFL.m
Elevation
According to the simulation report, the vapor compound's molecular weight falls within
the range of 21-31. After analyzing the release conditions of the gas, it has been
determined that the gas cloud may accumulate at the elevation of the leak source and
slightly above in the case of a horizontal release. Therefore, the elevation for detector
placement is considered to be around 500 mm above the potential source of leakage.
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Gas detection study
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Voting Logic
The following voting philosophy will be applied to the gas detection System.
Type of Action
Alarm Action
Executive Action
Voting logic
1ooN
Coverage
90%
2ooN
85%
References:
1. Gas Detection Philosophy (EE-6062-TS-PY-0001)
2. Process Simulation Report (0503223-01-PRO-RP-0002)
Comments:
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Gas detection study
Assumption register
Assumption No.:
Subject:
ASSUMPTION SHEET
04
Revision:
02F
ASSUMPTION
SHEET
Date:
21-01-2024
Gas Detection- Risk Volume/Cloud Size
Assumption:
Flammable Gas Detection Risk Volume/Cloud Size:
The gas cloud size determination depends on the principal (or most critical) gas that
is likely to be present,
Area Description
Congestion criteria
Target gas sphere
Enclosed or mostly Full walled/ Floored or Congested 5m
Enclosed
(more than 30% of volume
blockage ratio) area with 1 open
side
Partly enclosed
Congested area
Open area
or Congested area (more than 30% of 7m
volume blockage ratio) with 2 or
more open sides or process plant
with closely installed equipment
Light Congested area without walls 10m
Refer Appndix-2 for the character of GDZ accordingly the risk volume will be
considered.
References:
1. Gas Detection Philosophy (EE-6062-TS-PY-0001)
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Gas detection study
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Comments:
Assumption No.:
Subject:
ASSUMPTION SHEET
05
Revision:
02F
Date:
21-01-2024
Result presentation of 3-D Coverage
Assumption:
The coverage assessment results provided as snapshots/image in results section of the
report will be presented in the following color Key: -
References:
Comments:
Page | 24
Gas detection study
Assumption register
8 REFERENCES
•
Gas Detection Philosophy (EE-6062-TS-PY-0001)
Page | 25
Gas detection study
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9 APPENDICES
•
APPENDIX- 1 (GAS DETECTION ZONE LAYOUT)
•
APPENDIX- 2 (GAS DETECTION ZONE SCHEDULE)
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APPENDIX- 1 (GAS DETECTION ZONE LAYOUT)
Gas detection study
Assumption register
APPENDIX- 2 (GAS DETECTION ZONE SCHEDULE)
Gas Detection Zone Unit No.
GDZ-101-1
Inlet Manifold Area
GDZ-102-1
Separators & Raw Gas Metering
GDZ-103-1
Sales Gas Metering
GDZ-104-1
Tipu Compressors Area
GDZ-104-2
Tipu Process Plants
GDZ-105-1
Goru Membranes
GDZ-105-2
Goru /Tipu Pre-Heaters
GDZ-105-3 A/B/C
Amine Sweeting Units
GDZ-105-4
Dehydration Units
GDZ-105-5
ASU Hot Oil Heaters
GDZ-106-1
HRL Compressors Areas
GDZ-107-1
FEC area
GDZ-109-1
Condensate Stabilization &
Storage
GDZ-110-1
Fuel Gas
GDZ-110-2
Genset & MCC area
1.1
1.2
1.3
1.4
2.1
2.2
2.3
5.4
6.1
10.35
4.19
3.1
3.2
3.3
10.34
4.15
4.16
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
10.32
4.10
4.11
4.12
4.13
4.14
4.20
4.21
5.1
5.2
10.33
5.6
4.17
4.18
5.3
6.6
5.5
5.7
6.5
6.2
7.1
7.2
9.1
9.2
9.3
10.3
10.22
10.23
Facility / Equipment description
Goru B
Tipu
HRL / GHAZIJ
BHITTAI
Goru B
Tipu
HRL / GHAZIJ
(Goru-B) RAW GAS METERING
(HRL) RAW GAS METERING
ANALYZER FOR RAW GAS METERING
(TIPU) RAW GAS METERING
TIPU SALES GAS METERING
HRL SALES GAS METERING
GORU-B SALES GAS METERING
ANALYZER FOR SALES GAS METERING
BOOSTER COMPRESSORS
TIPU RECYCLE COMPRESSORS
FIRST STAGE MEMBRANE, SKID 1
SECOND STAGE MEMBRANE, SKID 2
GAS EXCHANGER
FILTER COALESCER
GUARD BED
PARTICLE FILTER
REGENERATION GAS COOLER
REGENERATION GAS SEPARATOR
CONDENSATE HEATER
ANALYZER FOR TWO STAGE MEMBRANE
CONDENSATE FLASH TANK
MEMGUARD ADSORBER WITH VALVE SKID
REGENERATION GAS BLOWER
FILTER COALESCER
PARTICLE FILTER (A/B)
RECYCLE COMPRESSOR DISCHARGE FILTER COALESCER
RECYCLE COMPRESSOR DISCHARGE GUARD BED
SINGLE STAGE MEMBRANE
PRE-TREATMENT
ANALYZER FOR SINGLE STAGE MEMBRANE
PREHEATER SKID
RE-GENERATION GAS HEATER
MEMBRANE PREHEATER
AMINE UNIT - 1 /2
AMINE UNIT - 3
DEHYDRATION SKID
Goru-B HOT OIL HEATER SKID
(HRL) HOT OIL HEATER SKID
HRL COMPRESSORS
FEC AREA
SALES GAS COMPRESSORS
CONDENSATE DEGASSER SKID
CONDENSATE STORAGE TANK
CONDENSATE LOADING PUMP
FUEL GAS SCRUBBER SKID
GAS GENSET
MCC ROOM
Zone Charecteristics
Open Area
Open Area
Open Area
Open Area
Open Area
Conjested Area
Open Area
Conjested Area
Open Area
Open Area
Open Area
Not installed
Open Area
Open Area
Open area
Remarks