Transcript
ADDAX ADDAX PETROLEUM DEVELOPMENT (NIGERIA) LIMITED
IZOMBE FLOWSTATION FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
IZOMBE FLOWSTATION FIRE AND AND GAS GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
Status: IFR Page 2 of 26
TABLE OF CONTENTS 1
INTRODUCTION .................................................................................................. 4
2
EXECUTIVE SUMMARY ...................................................................................... 4
2.1
Scope and Objectives of the Study ................... .......... ................... ................... .................. ................... ................... .................. ............... ...... 5
2.2
BOUNDARI BOUNDARIES ES ............................... ................................................ .................................. ................................. .................................. ............................... ............. 6
3
DEFINITIONS ....................................................................................................... 9
4
REFERENCES ..................................................................................................... 9
5
METHODOLOGY................................................................................................ 10
5.1
Event Tree Analysis ................... ......... ................... ................... ................... .................. ................... ................... ................... ................... ................. ........ 10
5.2
Fire Consequence Consequence and Gas Dispersion Modeling ................... .......... ................... ................... .................. ................... .......... 10
5.3
Hazardous Area Classification Classification .................. ......... ................... ................... ................... ................... .................. ................... ................... ........... .. 12
5.4
Fire and Gas Location Map ................... ......... ................... .................. ................... ................... ................... ................... ................... ................ ...... 13
5.5
Impact Assessment ................... ......... ................... ................... ................... .................. ................... ................... ................... ................... ................. ........ 13
6
DATA AND ASSUMPTIONS .......................... ............. .......................... .......................... .......................... .......................... ............... 13
6.1
Process Data .................. ......... ................... ................... .................. .................. ................... ................... ................... ................... .................. .................. ........... 13
6.2
Environmental Environmental Data ................... ......... ................... ................... ................... .................. ................... ................... ................... ................... ................. ........ 14
7
RESULTS AND RECOMMENDATIONS.......................... ............ ........................... .......................... ...................... ......... 17
APPENDIX I: EVENT TREE ANALYSIS ANALYSIS .............. .......................... ............. .......................... .......................... .................. ..... 18 APPENDIX II: FIRE CONSEQUENCE AND GAS DISPERSION MODELING ............. ............ . 20 APPENDIX III: PLOTS OF THERMAL RADIATION RADIATION CONTOURS ON WHP ................. ............ ..... 22 APPENDIX IV: SHELL FRED/MODELLING FRED/MODELLING REPORTS.......................... ............ .......................... ...................... .......... 23 APPENDIX V: PLOTS OF MINIMUM SAFE DISTANCES DISTANCES ................. .......................... ............. ............... 24 APPENDIX VI: HAZARDOUS AREA CLASSIFICATION CLASSIFICATION DRAWINGS .......................... ............ .............. 25 APPENDIX VII: FIRE AND GAS LOCATION MAPS ................. ........................... .............. ...................... ......... 26
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
Status: IFR Page 3 of 26
LIST OF TABLES Table 1: Summary of Environmental conditions ........................................................................ 14 Table 2: Tolerability Criteria ...................................................................................................... 15 Table 3 : Equipment Process Data ........................................................................................... 16 Table 4: Event Tree - Vapour Release ..................................................................................... 18 Table 5: Event Tree Analysis – Liquid Release ........................................................................ 19
LIST OF FIGURES Figure 1-1: The Izombe Process area Plot Plan ......................................................................... 7 Figure 1-2: Izombe Process Area Plot Plan showing safe distances........................................... 8
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
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Status: IFR Page 4 of 26
INTRODUCTION Izombe Flow station covers an approximate area of 74,000 acres in Izombe Village which is about 30km from Owerri. The production flow station has producing facilities that include well-heads, production manifolds, production separators, crude oil transfer pumps, storage tanks etc. (See Figure 1.1) In addition to local Izombe producing wells, flow lines from Ossu and Njaba production fields are tied into the Izombe manifold in an arrangement that enables it to be routed to Izombe flow station process f acilities
2
EXECUTIVE SUMMARY There is currently no Fire and Gas Detection or protection system on the main process facilities at the Izombe Flowstation. The Fire and Gas Assessment Study is carried out to achieve the following objectives: 1. Identify credible Gas release events 2. Identify Credible Fire scenarios 3. Evaluate Fire and Gas propagation models with respect to Safety Systems, Personnel and Asset Protection. 4. Identify Detection Types 5. Identify potential Fire and Gas Detection locations on Process Areas for optimal sensitivity 6. Evaluate Equipment Spacing 7. Identify high risk exposures 8. Recommend Options for implementing Fire Protection and achieve Asset Integrity Objectives for Izombe Flowstation Main Process Facilities The results of this study shall be utilized as an input into the design of the fire and gas protection system for Izombe Flowstation by APDNL The overall objective remains to operate the Izombe Production facilities with risks reduced to as Low as Reasonably Practicable (ALARP). The Fire Consequence and Gas Dispersion modelling is performed utilizing SHELL FRED 4.0 while calculating for different leak scenario to determine the possible radiant heat exposure to personnel and other process equipment. The recommendations from the study are as outlined below; 1.
Install Open Path Gas Detectors and Point Detectors at the indicated positions on the Main Process Facilities to provide full coverage for Gas Detection on the Process Area
2.
Install Flame Detectors as indicated on the Fire Protection System Layout. Open path detector coverage HP, LP and Gas lift Separators are considered critical.
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
Status: IFR Page 5 of 26
3.
Review Izombe Flowstation equipment and piping layout against the developed Hazardous Area Classification Drawing: Consider increasing the spacing between the HP and LP Separators to satisfy minimum separation distance requirements.
4.
The SDV/ESD at the inlets to HP and LP Separators are TOO CLOSE to the vessels to serve as credible barriers to isolate flow into the separators or process area. Consider modifying the piping to increase this distance.
5.
Design of the Izombe Process Facilities Fire Protection piping system should perform hydraulic analysis to ensure water and foam are sprayed at the appropriate pressure wherever required.
6.
Consider fire-proofing the structural legs of the pipe racks in the vicinity of Gas Scrubbers and Gas Pig Receiver. This would prolong the resistance time to fire radiation and retain structural integrity.
7.
Activation of the Fire protection system shall be based on Confirmed Fire or Confirmed Gas on a 2oo3 Voting System.
8.
Consider providing Security Camera monitor for the Process Area on Izombe Flowstation Control room.
The following appendices are attached to the report
2.1
1.
Appendix I:
Event Tree Analysis
2.
Appendix II:
Fire Consequence and Gas Dispersion Modelling Results
3.
Appendix III:
Plots of Thermal Radiation
4.
Appendix IV:
SHELL FRED Modelling Report
5.
Appendix V:
Plots of Minimum Safe Distance
6.
Appendix VI:
Hazardous Area Classification Drawings
7.
Appendix VII:
Fire and Gas Location Maps
Scope and Objectives of the Study The scope and objectives of this analysis are summarized as follows:
To assess the consequence of the accidental or intentional release of flammable hydrocarbon products on process equipment in terms of dispersion, fire and explosion To serve as input to the fire and gas detector location mapping study in determining the most effective location for the F& G system Evaluate the effects on escape devices and Safety equipment.
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
2.2
Status: IFR Page 6 of 26
BOUNDARIES The areas not included in the study scope and thus considered outside the evaluation boundaries are outlined below:
Environmental impacts of released hydrocarbons such as liquid spill, atmospheric pollution, etc. Catastrophic failures such as o
o
Full piping and/or vessel ruptures. Fire and explosion consequence resulting from failure of ESD and Shutdown valve failing to respond on demand.
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IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
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Document Title:
Rev:01
FIRE AND GAS ASSESSMENT STUDY REPORT
Nov 06, 2013
Status: IFR Page 7 of 26
Figure 2-1: The Izombe Process area Plot Plan
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IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01 Nov 06, 2013
Figure 2-2: Izombe Process Area Plot Plan showing safe distances
Status: IFR Page 8 of 26
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 8 of 26
Figure 2-2: Izombe Process Area Plot Plan showing safe distances
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
ADDNL-HSSL-FCGM-0002
Document Title:
Rev:01
FIRE AND GAS ASSESSMENT STUDY REPORT
Nov 06, 2013
3
DEFINITIONS Term
Definition
ALARP
As Low As Reasonably Possible
APDNL
Addax Petroleum Development Nigeria Limited
ATM
Atmospheres
EER
Escape, Evacuation and Rescue
ESD
Emergency Shutdown
FWS
Full Well Stream
FWKO
Free Water Knock out
HP
High Pressure
LEL
Lower Explosive Limit
LP
Low Pressure
OGP
International Association of Oil and Gas Producers
Status: IFR Page 9 of 26
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
ADDNL-HSSL-FCGM-0002
Document Title:
Rev:01
FIRE AND GAS ASSESSMENT STUDY REPORT
Nov 06, 2013
3
Page 9 of 26
DEFINITIONS Term
Definition
ALARP
As Low As Reasonably Possible
APDNL
Addax Petroleum Development Nigeria Limited
ATM
Atmospheres
EER
Escape, Evacuation and Rescue
ESD
Emergency Shutdown
FWS
Full Well Stream
FWKO
4
Status: IFR
Free Water Knock out
HP
High Pressure
LEL
Lower Explosive Limit
LP
Low Pressure
OGP
International Association of Oil and Gas Producers
PSLL
Pressure Switch Low Low
UEL
Upper Explosive Limit
USD
Utility Shutdown
VCE
Vapour Cloud Explosion
REFERENCES Document No.
Description
API RP 500
Recommended Practice For Classification Of Locations For Electrical Installations Classified As Class 1 Zone 0 And Zone 2
API 521
Guide For Pressure Relieving And Depressurization
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
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Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
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METHODOLOGY The following section describes the approach utilized in the Fire and Gas System Assessment Study. The process consists of the following:
5.1
Hazard Identification Event Tree Analysis Gas Dispersion Modeling Fire Consequence and Gas Dispersion Modeling Develop Hazardous Area Classification Drawing Impact Assessment Develop Fire and Gas Detectors Location Map Recommendations and Conclusions
Event Tree Analysis The event tree analysis was performed to further analyze the propagation of the initiating event (Loss of containment) to arrive at the final event outcomes by factoring in the following:
Probability of immediate ignition Probability of delayed ignition Probability of Failure on demand for shut-down valves Probability of creating overpressures. Probability of release occurring in the direction of receptor (Safety Equipment, EER System etc.)
One major result from the Event Tree Analysis is the selection of the final scenarios that are modeled using the Fire Consequence Modeling software. The Event Tree Analysis is shown in Appendix I.
5.2
Fire Consequence and Gas Dispersion Modeling The major basis of the Fire Consequence and Gas Dispersion Modelling Study is on hydrocarbon releases/loss of containment scenarios from 2.5mm, 5mm and 10mm leaks. This recognizes that minor leaks have higher likelihood to lead to continuous release as the PSLL may be unable to detect the pressure loss and initiate a shutdown. The study also recognized that larger leak sizes will lead to shutdown, thereby minimizing the loss of inventory. A worst case scenario for a 10mm vessel leak was developed with a wind speed of 10m/s. However the study also took cognizance of the potential for significant undetected gas release from Izombe Flow station process facilities, resulting from minor leaks. This also recognizes the failure of instrument impulse tubing, which may lead to significant hydrocarbon releases that may have the potential to form flammable vapour clouds.
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 11 of 26
Proposed recommendations to mitigate risks associated with significant vapour releases from minor leaks are also discussed In addition the UEL and LEL limits for unignited gas releases were also calculated to aid the identification of optimal positions for installation of fire and gas detectors to enable the timely detection of flammable concentrations from gas releases. The dispersion was modeled for 10%, 25%, 50% and 100% LEL limits The fire consequence scenarios are modeled using Computer based Modeling software (SHELL FRED 4.0). Computations shall model distances from the release point/source to thermal radiation contours of 16 kw/m2 and 32 kw/m2. The contours were plotted for the 16 kw/m 2 and 32 kw/m2 to ascertain the impact of the fire on surrounding equipment. The modeling shall consider the following;
Radiation Contours immediately following ignition Available inventory that feeds the leak Releases in the vertical, horizontal planes Pressure of vessel or piping at time of leak/release Other properties of released fluid Environmental conditions. Worst case conditions of wind towards the receptor (Safety Equipment) shall be used.
The consequence modeling is usually based on the propagation of the initiating loss of containment event. Based on the composition of the hydrocarbon fluid from the process simulation, two (2) different types of fluid release were utilized f or this study. The following assumptions are made for the fluid release scenario.
Liquid/Mixed (Phase) Release – It is assumed that fluid release from the lower/bottom part of the pipings is in the liquid phase. However, it is understood that the vapour (gas) component may still be contained in the liquid phase. Even when this is not the case, sustained release from the liquid side will ultimately lead to a mixed-phase release. Vapour/Gas (Phase) Release – It is assumed that release from the upper/top part of pipings is in the vapour phase. It is also modeled to release from the gas lines. This is also taken as the initial release condition. Continuous release may have liquids come out through the release point for the crude oil lines.
The distances for the two (2) distinct zones 16kw/m2 and 32kw/m2 of thermal radiation contour shall be recorded in tabular form. The contour distance table for modeled scenarios is in Appendix II. The 10%LEL, 25%LEL, 50%LEL 100%LEL and UFL contours table are depicted in Appendix II
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
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The representative plots of fire scenarios superimposed on the Izombe production facilities are made and presented in Appendix III
5.2.1
Jet Fire Scenario A jet fire is a turbulent diffusion flame resulting from the combustion of a fuel continuously released with some significant momentum in a particular direction or directions. Jet fires can arise from releases of gaseous, flashing liquid (two phase) and pure liquid inventories. The properties of jet fires depend on the fuel composition, release conditions, release rate, release geometry, direction and ambient wind conditions. The Jet Fire scenario is modeled using the process equipment source model which considers the release of material from its sto rage or process conditions in an equipment, through all the stages. The model provides the option to select the release phase of the fluid and it is also able to automatically calculate the release phase based on the fluid composition and the corresponding process condition of the fluid for a given equipment. The input parameters include, the fluid composition, the scenario type,(in this case a leak) as a minor leak, 2.5mm, 5mm and 10mm leaks. These are not considered as catastrophic rupture or line rupture cases. Other input parameters include the release source (pipe/vessel), location, geometry, process conditions, (include mass flow / containment pressure, temperature, volume of the vessel or piping), etc. The vapour/gas phase release is modeled to occur from t he upper part of the vessel, the two-phase release is modeled to occur from the liquid section in a vessel. The jet fire scenario also calculates the UEL and LEL distances for unignited releases. This is necessary to determine the effective location of gas detectors, simulations were carried out for 10%, 25% and 50% LEL limits.
5.3
Hazardous Area Classification A Hazardous Area Classification study was also carried out to identify areas within the Izombe facility where there is a high likelihood of explosive mixtures or atmosphere. This is to aid in the implementation of special precautions over likely sources of ignition to prevent fire and explosions. The hazardous area classification was carried out as an integral part of the risk assessment to identify areas where controls over ignition sources are needed (hazardous area) and also those areas where they are not (non hazardous areas). Hazardous areas are further classified in Zones which distinguish between locations that have a high chance of an explosive atmosphere occurring and those locations where an explosive atmosphere may only occur occasionally or in abnormal circumstances. The definitions of the Zones also recognize that the chance of a f ire or explosion depends on the likelihood of an explosive atmosphere occurring at the same time as an ignition source becomes active.
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
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ADDNL-HSSL-FCGM-0002 Rev:01
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A hazardous area can be further defined as a location where an explosive atmosphere may occur in quantities that require special precautions to protect the health and safety of workers. A location where an explosive atmosphere is not expected to occur in quantities that require such special precautions is deemed to be non-hazardous. For these purposes “special precautions” means precautions to control potential ignition sources within a hazardous area, particularly in relation to the use of equipment. The term “not expected to occur in such quantities” implies that consideration is also given to the likelihood of a loss of containment event (leaks) as well as the potential quantity of such releases when considering the area classification. Consequently an area can be classified as non-hazardous, if a release is extremely unlikely to occur and/or if the quantities released are small. The Hazardous Area Classification drawings are attached in Appendix VI
5.4
Fire and Gas Location Map A Fire and Gas Location Map was developed to describe the basis for the installation of a Fire and Gas protection system for the Izombe facility. The fire and gas location map shows the installation positions for the f ire and gas detectors. The function of the fire and gas detection systems is to primarily give warning of flammable releases or the outbreak of fire and to provide local indication and a control station alarm. The alarms enable the operators to take appropriate intervention and emergency actions. The F&G detection signals also operate protective functions. Sound engineering judgment and generic target scenarios were used to determine the location of the fire and gas detectors, based on the fire consequence models and analysis carried out for the Izombe facility. The flammable gas detection target (25%, 50% and 100% LFL) is set to detect those flammable gas releases that are generally large enough to potentially cause fire and explosion hazard, when undetected. Flame detection targets are set in line with typical fire events within the industry and also align with flame detector manufacturers’ specifications. The Fire and Gas Location Maps are attached in Appendix VII
5.5
Impact Assessment The impact of a potential loss of containment event leading to a fire was evaluated and minimum safe distances between equipment were recommended. The representative plots are shown in Appendix V.
6 6.1
DATA AND ASSUMPTIONS Process Data The composition of the fluid was collated from the Process Design Basis. The process conditions were collated from the Process & Instrumentation Diagram (P &ID) and on
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
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FIRE AND GAS ASSESSMENT STUDY REPORT
the Process Flow Diagram (PFD) and served as input data into the computer modeling equations. The equipment process data is shown in t able 7.3
6.2
Environmental Data The prevailing environmental conditions slightly affects the radiation effect distances thus the environmental conditions below have been selected with appropriate justification. Table 1: Summary of Environmental conditions Environmental Parameter Ambient temperature
6.2.1
Value
Justifications
23.80C 290C
Typical mean monthly temperature as presented by Nigeria Meteorological Agency Owerri Station weather report
Average daily relative humidity
80%
The lower the humidity, the lower the moisture content and the more heat is transmitted through the atmosphere. See API 521.(Ref 13)
Wind Speed
5 m/s
The effect of wind speed on the radiation contour specified for the scope of this study is minimal. However, it is conservative to use a low wind-speed to minimize the likelihood of a cooling effect and ensure accurate heat intensity is predicted.
Incident Solar Radiation
1.04KW/m2
See Table 8.6 API 521.(Ref 13)
Wind direction
NorthNorth East
Extracted from Izombe Flow Station Summary Basis However, evaluations were also made with respect to specific receptors, such as Safety Equipment location etc.
Main Hazards Areas The main hazard zones were identified based on the equipment layout on the process area, the main process equipment consist of Test separators, HP Separators, LP Separators, Gas Scrubber, Gas Lift Vessel, FWKO, Precipitator and inlet manifold. Scenarios from flanges and instrument tubing were also simulated due to their susceptibility to leaks.
6.2.2
Assessment Criteria The following assessment criteria have been used to assess fire & explosion effects resulting from oil & gas release on personnel and equipment.
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Document Number :
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 15 of 26
Table 2: Tolerability Criteria
SN
Exposure
1
.
Radiation from Pool/Jet fire
Human Fatality 12.5 kW/m2
For unprotected equipment
37.5kW/m2
Corresponding to the maximum allowable radiation flux for a protected equipment
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
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Rev:01
Status: IFR
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FIRE AND GAS ASSESSMENT STUDY REPORT
Table 3 : Equipment Process Data
EQUIPMENT
EQUIPMENT TAG
MAWP (Psig)
OPERATING PRESSURE (Psig)
OPERATING TEMP. (DEG F)
FLOW RATE
FLUID
LP SEPARATOR
V-100
230
125
102
15,554 BBL
Partially stabilized Oil
HP SEPARATOR
V-200
230
120
100
15,554 BBL
Partially stabilized Oil
GAS LIFT VESSEL
V-210
1440
1440
111
NA
Partially stabilized Oil
FWKO
V-300
50
27
110
31,108
Partially stabilized Oil
PRECIPITATOR
V-400
50
22
108
NA
Partially stabilized Oil
TEST SEPARATOR
V-1500
230
120
84
NA
Partially stabilized Oil
GAS SCRUBBER
V-3000
230
1500--isolated
83
NA
Partially stabilized Oil
CRUDE OIL TRANSFER PUMPS
P-100/200
30
98
600 GPM
Partially stabilized Oil
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ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
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RESULTS AND RECOMMENDATIONS 1. Install Open Path Gas Detectors and Point Detectors at the indicated positions on the Main Process Facilities to provide full coverage for Gas Detection on the Process Area 2. Install Flame Detectors as indicated on the Fire Protection System Layout. Open path detector coverage HP, LP and Gaslift Separators are considered critical. 3. Review Izombe Flowstation equipment and piping layout against the developed Hazardous Area Classification Drawing: Consider increasing the spacing between the HP and LP Separators to satisfy minimum separation distance requirements. 4. The SDV/ESD at the inlets to HP and LP Separators are TOO CLOSE to the vessels to serve as credible barriers to isolate flow into the separators or process area. Consider modifying the piping to increase this distance. 5. Design of the Izombe Process Facilities Fire Protection piping system should perform hydraulic analysis to ensure water and foam are sprayed at the appropriate pressure wherever required. 6. Consider fire-proofing the structural legs of the piperacks in the vicinity of Gas Scrubbers and Gas Pig Receiver. This would prolong the resistance time to fire radiation and retain structural integrity.
Document Number :
IZOMBE FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
7
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 17 of 26
RESULTS AND RECOMMENDATIONS 1. Install Open Path Gas Detectors and Point Detectors at the indicated positions on the Main Process Facilities to provide full coverage for Gas Detection on the Process Area 2. Install Flame Detectors as indicated on the Fire Protection System Layout. Open path detector coverage HP, LP and Gaslift Separators are considered critical. 3. Review Izombe Flowstation equipment and piping layout against the developed Hazardous Area Classification Drawing: Consider increasing the spacing between the HP and LP Separators to satisfy minimum separation distance requirements. 4. The SDV/ESD at the inlets to HP and LP Separators are TOO CLOSE to the vessels to serve as credible barriers to isolate flow into the separators or process area. Consider modifying the piping to increase this distance. 5. Design of the Izombe Process Facilities Fire Protection piping system should perform hydraulic analysis to ensure water and foam are sprayed at the appropriate pressure wherever required. 6. Consider fire-proofing the structural legs of the piperacks in the vicinity of Gas Scrubbers and Gas Pig Receiver. This would prolong the resistance time to fire radiation and retain structural integrity. 7. Activation of the Fire protection system shall be based on Confirmed Fire or Confirmed Gas on a 2oo3 Voting System. 8. Consider providing Security Camera monitor for the Process Area on Izombe Flowstation Control room.
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
ADDNL-HSSL-FCGM-0002
Document Title:
Rev:01
Status: IFR
Nov 06, 2013
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FIRE AND GAS ASSESSMENT STUDY REPORT
APPENDIX I: EVENT TREE ANALYSIS Table 4: Event Tree - Vapour Release
1st Protection Layer INITIATING EVENT ID
2nd Protection Layer
INITIATING EVENT FREQUENCY
LEAK DETECTION & SHUT-DOWN FAILS
IMMEDIATE IGNITION
FIRE DETECTION & ESD FAILS
EXPLOSION
OUTCOME
Po
Pa
Pb
Pc
Pd
Outcome Frequency
Yes
I: Jet Fire
No
II: Flash Fire.
IMPACT CATEGORY
MAJOR
Yes Yes
Loss of Containment (Initiating Event)
Yes
MINOR
III: Vapour Cloud Explosion
SERIOUS
No No
IV: Unignited Gas Cloud
No
INCIDENTAL
V: No/Minor Accident
INCIDENTAL
Document Number :
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Document Title:
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Status: IFR
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FIRE AND GAS ASSESSMENT STUDY REPORT
Table 5: Event Tree Analysis – Liquid Release
1st Protection Layer INITIATING EVENT ID
2nd Protection Layer
INITIARTING EVENT FREQUENCY
LEAK DETECTION & SHUT-DOWN FAILS
IMMEDIATE IGNITION
FIRE DETECTION & ESD FAILS
EXPLOSION
OUTCOME
Po
Pa
Pb
Pc
Pd
Outcome Frequency
Yes
I: Jet Fire + Spill
No
II: Flash/Moderat e Pool Fire.
IMPACT CTEGORY
MAJOR
Yes
Yes
Loss of Containment (Initiating Event)
Yes
III: Vapour Cloud Explosion
MINOR
SERIOUS
No No
No
IV: Unignited Liquid Pool
V: Minor Spill (Controlled)
SERIOUS
INCIDENTAL
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
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Document Title:
Rev:01
Status: IFR
Nov 06, 2013
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FIRE AND GAS ASSESSMENT STUDY REPORT
Table 5: Event Tree Analysis – Liquid Release
1st Protection Layer INITIATING EVENT ID
2nd Protection Layer
INITIARTING EVENT FREQUENCY
LEAK DETECTION & SHUT-DOWN FAILS
IMMEDIATE IGNITION
FIRE DETECTION & ESD FAILS
EXPLOSION
OUTCOME
Po
Pa
Pb
Pc
Pd
Outcome Frequency
Yes
I: Jet Fire + Spill
No
II: Flash/Moderat e Pool Fire.
IMPACT CTEGORY
MAJOR
Yes
Yes
Loss of Containment (Initiating Event)
Yes
MINOR
III: Vapour Cloud Explosion
SERIOUS
No No
IV: Unignited Liquid Pool
No
SERIOUS
V: Minor Spill (Controlled)
INCIDENTAL
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
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Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
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Status: IFR
Nov 06, 2013
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APPENDIX II: FIRE CONSEQUENCE AND GAS DISPERSION MODELING RESULTS
EQUIPMENT/PIPING (AT 5MPS WIND SPEED) GAS SCRUBBER
GAS LIFT VESSEL
GAS PIG RECEIVER
GAS PIPE RACK
Modelled Release Size(mm)
Flame Length (m)
16kw/m2
32kw/m2
10%LFL (m)
50% LFL (m)
LFL (m)
UFL
(m)
2.5
2.2616
2.49
2.41
4.5
1.6
0.9
5.0
3.938
4.38
4.23
8.0
3.0
1.7
0.5
10.0
6.862
7.74
7.43
15.0
5.5
3.0
1.1
2.5
2.2557
2.48
2.4
4.5
1.6
0.9
0.3
5.0
3.929
4.37
4.22
8.0
3.0
1.7
0.5
10
6.845
7.72
7.41
15.0
5.5
3.0
1.1
2.5
2.3201
2.55
2.47
4.5
1.6
0.9
0.3
5.0
4.041
4.49
4.34
8.0
3.0
1.7
0.6
10.0
7.04
7.94
7.62
16.0
5.5
3.0
1.2
2.5
1.6746
2.23
2.03
3.5
1.2
0.6
0.2
5.0
2.918
3.23
3.12
6.5
2.0
1.2
0.4
10.0
5.081
5.71
5.49
12.0
4.0
2.0
0.8
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
ADDNL-HSSL-FCGM-0002
Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
Rev:01
Status: IFR
Nov 06, 2013
Page 20 of 26
APPENDIX II: FIRE CONSEQUENCE AND GAS DISPERSION MODELING RESULTS
EQUIPMENT/PIPING (AT 5MPS WIND SPEED) GAS SCRUBBER
GAS LIFT VESSEL
GAS PIG RECEIVER
GAS PIPE RACK
Modelled Release Size(mm)
Flame Length (m)
16kw/m2
32kw/m2
10%LFL (m)
50% LFL (m)
LFL (m)
UFL
(m)
2.5
2.2616
2.49
2.41
4.5
1.6
0.9
5.0
3.938
4.38
4.23
8.0
3.0
1.7
0.5
10.0
6.862
7.74
7.43
15.0
5.5
3.0
1.1
2.5
2.2557
2.48
2.4
4.5
1.6
0.9
0.3
5.0
3.929
4.37
4.22
8.0
3.0
1.7
0.5
10
6.845
7.72
7.41
15.0
5.5
3.0
1.1
2.5
2.3201
2.55
2.47
4.5
1.6
0.9
0.3
5.0
4.041
4.49
4.34
8.0
3.0
1.7
0.6
10.0
7.04
7.94
7.62
16.0
5.5
3.0
1.2
2.5
1.6746
2.23
2.03
3.5
1.2
0.6
0.2
5.0
2.918
3.23
3.12
6.5
2.0
1.2
0.4
10.0
5.081
5.71
5.49
12.0
4.0
2.0
0.8
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
EQUIPMENT/PIPING (AT 5MPS WIND SPEED) TEST SEPARATOR
HP SEPARATOR
LP SEPARATOR
INLET MANIFOLD
Modelled Release Size(mm)
Flame Length (m)
16kw/m2
32kw/m2
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 21 of 26
10%LFL
50% LFL
(m)
(m)
LFL (m)
UFL (m)
2.5
3.0438
3.92
3.61
5.7
3.0
2.0
0.8
5.0
5.297
2.37
2.32
11.19
5.5
4.0
1.6
10.0
9.2316
12.79
11.56
27.21
9.5
7.0
3.0
2.5
2.8533
3.59
3.33
5.75
3.0
2.0
0.7
5.0
4.9682
6.46
5.94
10.11
5.0
3.5
1.3
10.0
8.6526
11.68
10.62
24.14
9.0
6.5
2.5
2.5
2.7122
3.36
3.13
5.78
2.5
1.9
0.6
5.0
4.7224
6.04
5.57
10.11
5.0
3.5
1.2
10.0
8.2258
10.88
9.95
22.96
8.5
6.0
2.0
2.5
4.678
6.49
5.87
9.22
5.0
3.5
1.5
5.0
8.1458
11.8
10.54
21.81
8.49
6.5
2.5
10.0
14.1816
21.4
18.96
46.69
23.6 9
12. 99
5.0
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT
ADDNL-HSSL-FCGM-0002
Document Title:
Rev:01
Status: IFR
Nov 06, 2013
Page 21 of 26
FIRE AND GAS ASSESSMENT STUDY REPORT
EQUIPMENT/PIPING (AT 5MPS WIND SPEED) TEST SEPARATOR
HP SEPARATOR
LP SEPARATOR
INLET MANIFOLD
Modelled Release Size(mm)
Flame Length (m)
16kw/m2
32kw/m2
10%LFL
50% LFL
(m)
(m)
LFL (m)
UFL (m)
2.5
3.0438
3.92
3.61
5.7
3.0
2.0
0.8
5.0
5.297
2.37
2.32
11.19
5.5
4.0
1.6
10.0
9.2316
12.79
11.56
27.21
9.5
7.0
3.0
2.5
2.8533
3.59
3.33
5.75
3.0
2.0
0.7
5.0
4.9682
6.46
5.94
10.11
5.0
3.5
1.3
10.0
8.6526
11.68
10.62
24.14
9.0
6.5
2.5
2.5
2.7122
3.36
3.13
5.78
2.5
1.9
0.6
5.0
4.7224
6.04
5.57
10.11
5.0
3.5
1.2
10.0
8.2258
10.88
9.95
22.96
8.5
6.0
2.0
2.5
4.678
6.49
5.87
9.22
5.0
3.5
1.5
5.0
8.1458
11.8
10.54
21.81
8.49
6.5
2.5
10.0
14.1816
21.4
18.96
46.69
23.6 9
12. 99
5.0
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 22 of 26
APPENDIX III: PLOTS OF THERMAL RADIATION CONTOURS ON WHP
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 22 of 26
APPENDIX III: PLOTS OF THERMAL RADIATION CONTOURS ON WHP
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
APPENDIX IV: SHELL FRED/MODELLING REPORTS
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 23 of 26
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
APPENDIX V: PLOTS OF MINIMUM SAFE DISTANCES
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 24 of 26
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 25 of 26
APPENDIX VI: HAZARDOUS AREA CLASSIFICATION DRAWINGS
Document Number :
IZOMBE FLOWSTATION FIRE AND GAS SYSTEM ASSESSMENT Document Title:
FIRE AND GAS ASSESSMENT STUDY REPORT
APPENDIX VII: FIRE AND GAS LOCATION MAPS
ADDNL-HSSL-FCGM-0002 Rev:01
Status: IFR
Nov 06, 2013
Page 26 of 26
