FEED FOR THE REHABILITATION / UPGRADE OF DELTA IV

METERING STATION PROJECT

Nigerian Gas Processing
Weam & Company Ltd and Transportation Co. Ltd.
Petroleum Corporation
HAZARD AND OPERABILITY STUDY REPORT

HAZARD AND OPERABILITY STUDY

REPORT

Conducted and prepared by

Process Safety & Loss Prevention

Engineering Consultants

FOR
WEAM AND COMPANY LIMITED

29th March,2018
 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Revision record

2 - Approved for delivery - - -

1 Issued for
30/03/18 review/comments - - -
0 29/03/18 Initial draft -. - -
Rev. Date Description Prepared by Checked by Approved by

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TABLE OF CONTENTS

1. ABBREVIATIONS ......................................................................................................... 4
2. EXECUTIVE SUMMARY ................................................................................................ 5
3. INTRODUCTION .......................................................................................................... 5
4. PROCESS AND EQUIPMENT DESCRIPTION................................................................. 6
4.1 FILTER SEPARATOR ........................................................................................... 7
4.2 GAS HEATER SYSTEM ....................................................................................... 8
4.3 PRESSURE REDUCTION SYSTEM ....................................................................... 9
4.4 METERING AND EXPORT SYSTEM .................................................................. 10
4.5 INSTRUMENT GAS SYSTEM ............................................................................. 11

5. PROJECT DESCRIPTION ............................................................................................ 12

6. HAZOP PURPOSE/OBJECTIVES................................................................................. 13
7. HAZOP SCOPE .......................................................................................................... 13
8. HAZOP PROCESS ...................................................................................................... 14
9. METHODOLOGY ....................................................................................................... 14
10. DISCUSSION.............................................................................................................. 15
11. RECOMMENDATIONS............................................................................................... 15
12. APPENDICES ............................................................................................................. 17
13. APPENDIX-1: HAZOP ATTENDANCE ........................................................................ 18
14. APPENDIX-2: TABLES AND FIGURES ......................................................................... 20
15. APPENDIX 4: HAZOP WORK SHEET .......................................................................... 33

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1. ABBREVIATIONS

AG Above Ground
BLV Ball Valve
CFR Code of Federal Regulation
ESD Emergency Shutdown
F&G Fire and Gas
FSV Flow Safety Valve
HAZOP Hazard and Operability Study
LAHH Level Alarm High High
LCV Level Control Valve
NGPTC Nigeria Gas Processing and Transportation Company
P&ID Piping and Instrumentation Drawing
PAH Pressure Alarm High
PAHH Pressure Alarm High High
PCV Pressure Control Valve
PDAH Pressure Differential Alarm High
PDI Pressure Differential Indicator
PG Pressure Gauge
PHA Process Hazard Analysis
PRS Pressure Reduction System
PSH Pressure Switch High
PSLL Pressure Switch Low Low
PSSR Prestart up Safety Review
PT Pressure Transmitter
SCEs Safety Critical Equipment(Elements)
SCFD Standard Cubic Feet per Day
SDV Shut Down Valve
SOP Standard Operating Procedure
TCV Temperature Control Valve
TI Temperature Indicator
TT Temperature transmitter
UG Under ground

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2. EXECUTIVE SUMMARY
The Nigeria Gas Processing and Transportation Company (NGPTC) commissioned
Weam and Company Limited to carry out the Front End Engineering Design for
the Rehabilitation/Upgrade works on Delta IV Metering Station, Delta State.

In line with the above, the Engineering and Design Company, Weam and Company
Limited contacted DM Sheffield Limited as an independent consultant to handle the
HAZOP package.

HAZOP was utilized as the best Process Hazard Analysis (PHA) method to identify and
manage hazards and operability issues related to the project.

This report presents the results of the HAZOP study, which took place on
22nd March 2018.

During the HAZOP study, over 10 Recommendations/Actions items were discussed

amongst the HAZOP team and issued in this report. The implementation of the
recommendations will be an input into the improvement of the existing design and
safety management of the facility.

For details of the HAZOP recommendations/action item, please refer to

Appendix-3, page 29 of this report.

To confirm the improved safety of the facility, we recommend that another HAZOP or
post HAZOP compliance review be carried out after the detailed engineering design
phase. This is essential, especially if there are major changes to the current design
(P&IDs) and operations philosophy.

Major changes to P&ID and other processes may invalidate the correctness of the
FEED phase HAZOP. It is therefore, strongly recommended to ensure that
Management of Change (MOC) process is applied to track possible changes to
design and other important processes, control philosophies and procedures.

3. INTRODUCTION
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Delta IV Metering station is an Onshore Gas Metering Station located in Delta

State, and owned/operated by Nigerian Gas Processing and Transportation
Company (NGPTC) Ltd. This facility was constructed in 1986. The major equipment in
the station are: (1) Filter Separator (2) Gas Heater Unit (3) Pressure reduction unit and
(4) Meters. The station is currently running on an obsolete control and shutdown
system and has in the past experienced a fire incident. After 30 years operations
with attendant challenges, it is clearer that NGPTC can no longer operate the
facility at present status and control method. More so, increased customer
demand is envisaged in the near future. Therefore in a bid to ensure the reliability of
gas supply to customers and safe operation of the facility with adequate
automation, Weam and Company Limited was contracted to provide Front End
Engineering Design for the Rehabilitation/Upgrade works on Delta IV Metering
Station by Nigerian Gas Processing and Transportation Company (NGPTC) Ltd.

Following the above, NGPTC awarded the FEED/Upgrade of the metering facility to
Weam and Company Limited. The upgrade of the facility is to effectively reduce
and manage process and operations challenges whilst ensuring safer operations and
excellence in operations.

In compliance with best industry practice 29 CFR 1910.119 (conducting Process

Hazard Analysis using HAZOP technique), Weam and Company Limited contracted
the HAZOP facilitation (third party/independent facilitator) to DM SHEFFIELD LTD, a
Process Safety and Loss Prevention Engineering Company to facilitate the HAZOP
workshop.

4. PROCESS AND EQUIPMENT DESCRIPTION

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Delta IV Metering station consist of the following equipment/process below:

1. Filter Separator
2. Gas Heater Unit
3. Pressure reduction unit
4. Metering system and
5. Instrument Gas System.

PFD of the Metering Station

4.1 FILTER SEPARATOR

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Filtration System Description

This consisted of a single line filtration system which serves as liquid scrubber. It
involved a single stage, 2 phase (Gas & Liquid) Separation configuration.

The equipment is fitted with 2 control valves, 1 high level shutdown and 1 low level
shutdown, fitted at the liquid outlet piping of the vessel. The following are fitted at the
top of the vessel: a Relief valve, Manual blow-down valve, and a pressure
differential indicator.

P&ID of Filter Separator

4.2 GAS HEATER SYSTEM

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There are two gas heaters in the facility (F-500 and F-501). This comprises of an
indirect Heating water bath system, fired by fuel gas taken downstream the Pressure
regulating piping. Here the Stream temperature is raised to 40 deg Celsius. The
Heaters are insulated and equipped with an overhead expansion tank, and double
Flue stack and burners.

P&ID of Gas Heater System

4.3 PRESSURE REDUCTION SYSTEM

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At present, the facility has a skidded gas pressure reduction system. The system
reduces gas pressure to meet customer gas specification of 22barg. Each of the 3
lines of the gas reduction system has a capacity of 60MMSCFD. At each time, only 2
lines are on duty and complimentary at 50% of throughput, while one is redundant.
The pressure and temperature at the discharge of the pressure reduction skid is 22
Bar and 30oc respectively.

P&ID of Pressure Reduction System

4.4 METERING AND EXPORT SYSTEM

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There are 2 Daniel orifice meters on site. At present, gas is exported via an 18 inch
pipeline. The facility supplies gas to only one customer (Transcorp) at a flowrate of 35
– 100 MMSCFD; this is below the installed capacity of the station (172 MMSCFD).
There are no provisions for tie in points for gas sales export to other customers. The
gas is delivered to the customer at a temperature of 30oc and pressure of 22 barg.

P&ID of Metering System

4.5 INSTRUMENT GAS SYSTEM

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The facility has an instrument/fuel gas skid that supplies instrument gas to the Utility
system (instruments & Fuel Gas) in the station. However, the fuel gas requirement of
the heater is supplied from the exit manifold of the Pressure Reduction Skid.

The skid receives gas from the outlet of the water heaters at a temperature of 40 oc
and pressure of 7.5 bar. It is also designed to receive gas from the inlet line (at about
29 oc) to the facility but that’s only used at start up before being switched to the
heater outlet line after the system stabilizes. The skid consists of isolating valves, check
valves, filters and relief valves.

P&ID of Instrument Gas System

5. PROJECT DESCRIPTION

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Delta IV Metering station is an Onshore Gas Metering Station located in Delta State,
and owned/operated by the Nigerian Gas Processing and Transportation Company
(NGPTC) Ltd. This facility was constructed in 1976. The major equipment in the station
are:
(1) Filter Separator
(2) Gas Heater Unit
(3) Pressure reduction unit (4) Meters and
(5) Instrument Gas System.
The station is currently running on an obsolete control and shutdown system and has
in the past experienced a fire incident. After over 40 years of operation with
attendant challenges, it is clearer that NGPTC can no longer operate the facility at
its present underutilized installed capacity and epileptic supply, and control system,
to customers. More so, increased customer demand is envisaged in the near future.
Therefore in a bid to ensure the reliability of gas supply to customers and safe
operation of the facility with adequate automation, Weam and Company Limited
was contracted to provide Front End Engineering Design for the
Rehabilitation/Upgrade works on Delta IV Metering Station by Nigerian Gas
Processing and Transportation Company (NGPTC) Ltd.
The FEED Scope for facilities upgrade should amongst others centre on the following:

1. The Re-engineering of the facility to incorporate more stream Tie-ins, modern

control & automation system, and more reliable safe operation at 172mmscfd.
2. Preparation of Material-Take-Off (MTO), Specifications, Data sheets for enquiries
for placement of Purchase order of all identified long lead items (LLI’s) required
for the works.
3. The upgrade /rehabilitation works in line with NGPTC requirement. The project will
be executed in two major phases.
The first phase is the development of AS-IS documents for the facility which will form
the basis for the second phase of the project which is the Re-engineering phase.
The project scope at the gas station consists of tie-ins, brownfield modification and
upgrades together with the installation of new equipment where the need arises.

6. HAZOP PURPOSE/OBJECTIVES

The primary objective of the HAZOP study is to identify the causes, consequences
and provide existing safeguards for credible hazards and operability challenges.
7. HAZOP SCOPE

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The scope of the HAZOP covers the main components/process of the metering
system as contained in the process flow diagram.

The scope was defined by the metering station and processes outlined within the
process flow drawing. The HAZOP study was based on the design and normal
operating conditions of the metering station and discrete process/operations
equipment.

8. HAZOP PROCESS
The methodology involves a structured, systematic and comprehensive examination
of process flow sheets, flow diagrams, plant/facility layouts, basis for design, process
and control philosophy, cause and effects and other necessary documents in order
to identify potential hazards and operability challenges. The study was undertaken
by a multi-disciplinary team (process, electrical, Instrumentation and control, piping,
safety etc) familiar with the metering system.

An independent HAZOP chairman or facilitator was invited to review all required

documents and also to facilitate the HAZOP workshop together with the multi-
disciplinary team.

The role of the HAZOP was to guide and encourage the study team through the
examination process to identify all possible hazard and operability scenarios.

A scribe (Secretary) was part of the team. The scribe documented the salient
points/findings of the study.

The HAZOPs process/workshop provided a platform for the team to visualize ways in
which a plant can malfunction or mal-operate. This creative thinking of individuals
was guided and stimulated in a systematic fashion by the use of prompt guide words
to cover all imaginable malfunctions and mal-operations.

9. METHODOLOGY
The overview of the NGPTC metering station system design (process flow scheme)
was initially discussed with the team before the commencement of the HAZOP.PFD
overview was part of the HAZOP process. To facilitate the HAZOP process, the
individual process steps for the re-engineered process and normal operations were
reviewed and subsequently grouped to define the HAZOP nodes. A short Briefing
Note was made available in advance of the HAZOP meeting that listed the Nodes
and Keywords to be used through the HAZOP chairman.

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The nodes used during the HAZOP are shown in Table 1. These nodes were
subject to the HAZOP study process.

The nodes were examined for deviations from the overall design intent using
standard HAZOP methodology by the application of a series of keywords. Where a
keyword was not applicable to a particular node or no additional hazards were
identified relevant to the keyword, this was noted as such in the worksheets.

Having identified the consequences and any existing safeguards, the team made a
decision as to whether this is tolerable by using a simple risk ranking scale to score
the severity and the likelihood of the scenario. If it was not considered tolerable,
then a recommendation was made which should reduce the severity or the
frequency of the consequence being realised. Each recommendation was
allocated to a member of the HAZOP Team, who will be responsible for addressing
the issues raised outside the HAZOP meeting.

The meeting discussions were recorded interactively by the scribe on a Personal

Computer (PC) via dedicated HAZOP work sheet. The HAZOP team viewed and
agreed the record “live” by means of a projection system connected to the PC in
the meeting room and hence the HAZOP worksheets effectively represent the
minutes of the meeting. The HAZOP worksheets are presented in Appendix.

Where additional information was required or changes to the concept design were
considered by the HAZOP team as constituting a potential improvement, actions /
recommendations were raised or comments made.

10. DISCUSSION

During the HAZOP Study over 10 Recommendations (Actions) were issued. The
Recommendations have been extracted from the worksheets and included in
Appendix 3 in expanded form to be “stand alone”. It is expected that both WEAM
and NGPTC management and HAZOP team will review the recommendations and
consider implementation as the case may be.

11. RECOMMENDATIONS
The hazards associated with the metering station can be reduced further by the
satisfactory implementation of the outcome from the recommendations – HAZOP
action sheets included at Appendix 3.

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To confirm the improved safety of the system, a second HAZOP or post HAZOP review
should be conducted on the final or detailed engineering design.
The above is dependent on the level of changes on the design (PFDs, P&IDs, C&E,
Control and operations philosophies etc.).

There are recommendations which relate to the consideration of additional

instrumentation or engineered modifications with a view to enhancing the safety of
the system. It may be prudent to assess the impact of these modifications on the
overall probability of failure of the system prior to implementation.

It is important that during and after construction phase but before commissioning, a
post HAZOP review be conducted. This is to ensure that all the recommendations are
fully complied with in other to provide the improved safety system of the process. For
ease of follow up and implementation, best practices recommends that the HAZOP
facilitator and key team members from the engineering company, EPC contractor
and the client should jointly conduct the post HAZOP review.

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12. APPENDICES
Contents
Appendix 1: HAZOP Attendees

Appendix 2: Tables and Figures

Appendix 3: Recommendation/HAZOP Actions

Appendix 4: HAZOP Worksheet

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13. APPENDIX-1: HAZOP ATTENDANCE

HAZOP Attendance
The HAZOP workshop took place on the 22nd March, 2018; in the conference room of Weam
and Company Limited, located at Plot 42C, Road 22, Federal Housing Estate, Rumueme, Port
Harcourt, Rivers State.

Twenty (20) persons attended the 1-day HAZOP work shop.

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Note: All the nodes were HAZOPed on same day (22nd March, 2018).

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14. APPENDIX-2: TABLES AND FIGURES

Contents

Table 1 HAZOP Nodes

Table 2 HAZOP Guides / Keywords
Figure 1 P and ID Diagram – Filter Separator
Figure 2 P and ID Diagram – Heater System
Figure 3 P and ID Diagram – Pressure Reduction Metering
Figure 4 P and ID Diagram – Metering System
Figure 5 P and ID Diagram – Instrument Gas Skid

Tables and Figures

Table-1: HAZOP Nodes

Node Description

NODE-1 : FILTER SEPARATOR

Drawing No: NGPTC-W-130148

1
(Including line/vessel through
 10’’ –PG- 50002-D600
 10’ –PG- 50101-D600
 10’ –PG- 50020-D600
 V-500
and other lines and their components.

2 NODE-2 : GAS HEATER UNIT/SYSTEM

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Drawing No: NGPTC-W-156281

(Including lines/components/equipment through
 10’’ –PG- 50020-D600
 8’’ –PG-40001-D600
 8’’ –PG-40105-D600
 H-400 & H-401

3 NODE-3 : PRESSURE REDUCTION SYSTEM

Drawing No: NGPTC-W-127881
(Including lines/components/equipment through

 12” –PG-30005-B300
 18” –PG-30008-B300
 10” –PG-30001-D300
 18” –PG-20001-B300 and other headers

NODE-4 : METERING SYSTEM

Drawing No: NGPTC-W-125885
4
Including lines through;
 18’’-PG-20002-B300
 18’’-PG-20001-B300
 18’’-PG-20003-B300
 18’’-PG-20004-B300
And other line components.
NODE-5 : INSTRUMENT GAS SKID
Drawing No: NGPTC-W-129991
Including lines through;
5
 2’’-1G-40104-D600

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 5/8’’-PC-50001-D600
 2’’ –IG-50001-D600
 F-1 & F-2 and other components

Table 2: HAZOP Guide/Keywords

Zzzzzz Keywords

Level Low level, high level,

No flow, Low flow, more flow, reverse
Flow
flow
No pressure, Low pressure, high
Pressure
pressure
Temperature Low temperature, high temperature
Others
Corrosion/Erosion

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Figure 1: Process and Instrumentation Diagram

Filter Separator

NODE-1: FILTER SEPARATOR

001B

001A

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Figure 2: Process and Instrumentation Diagram

Gas Heater Unit

NODE-002: GAS HEATER UNIT

002B

002A

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Figure 3: Process and Instrumentation Diagram

(Pressure Reduction System)

003D NODE-003: Pressure Reduction System

003A 003B 003C

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Figure 4: Process and Instrumentation Diagram

(Pressure Reduction System)

NODE-004: METERING STATION

004B

004A

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APPENDIX-3: HAZOP RECOMMENDATION AND ACTION SHEET

Node Guideword Cause/ Concern Recommendation Action

Party
001-Filter Pressure Vessel below V-500 Provide tag name/no. WEAM
Separator which serve as For vessel
condensate collector is
not tagged.
002- Heater Flow No/low flow/pressure Incorporate by-pass
inlet outlet of heater, line (Globe & ball WEAM &
likely to cause unwanted valve) on the 401-TCV- NGPTC
system shutdown 001 to enable
maintenance without
system shutdown.
Install dual by-pass (ball
valve) and flow control
valve to possibly
prevent unwanted
shutdown due to low
flow condition.
003- Flow Current design of Consider to install PSLL
Pressure SDV/ESD response to at the inlet of the PRS to WEAM &
Reduction system demand will not respond to ‘’LL’’ NGPTC
System shutdown system on Low condition and initiate
Low condition. system shutdown.
Flow/pressur Operator’s error e.g an Develop and
e operator inadvertently implement specific NGPTC
left isolation valves(BLVs) Standard Operating
open or close, causing Procedure(SOP),
no/low flow/pressure Prestart Up Safety
and likely to cause Review (PSSR)
operability issues. Procedure/checklist to
address critical
operator’s error such as
this.

Node Guideword Cause/ Concern Recommendation Action

Party
003- Flow/pressur Possible Release of Confirm if existing F&G
Pressure e flammable gas due to detection/voting WEAM &

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Reduction operator’s error; architecture and NGPTC

System erroneously open a mapping are
valve or left it open. adequate and suitable.
Also confirm if F&G
system is designed to
shutdown the system
upon detection of
flammable gas cloud
based on G.D set
points.
Conduct an intensive
Line rupture/leak due to Risked Based NGPTC
possible weak/aged Inspection(RBI) of the
equipment entire facility to
(Corrosion/erosion of establish current
SCEs) leading to integrity of the SCEs(e.g
flammable gas release. Piping, pipeline, vessels,
posing danger to sensing and monitoring
operator/facility equipment etc)
operations. Develop and
implement NGPTC
performance standards
for SCEs.
004- Flow/pressur Current alarm design will Consider to redesign WEAM &
Metering e only initiate system alarm system to also NGPTC
System shutdown on PAH & PAL initiate system
conditions. shutdown on PAHH &
PALL conditions.
The advantage is that it
will allow operator’s
intervention and also
prevent unwanted
shutdown.
3nos FT on 200-BLV-004 Consider to remove WEAM &
on both meter headers one FT. NGPTC
may be considered over
design as 2nos FTs will be
suitable to cascade or
transmit flow conditions
to the panel.
005 Flow No equipment tag Provide equipment Tag WEAM
Instrument no./name for instrument No./name
Gas Skid buffer tank

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PAHL on single stem Consider to review all

fitted to 500-PAHL-015 similar design and
likely to encounter redesign to have PAH &
common failure due to PAL separated.
possible fouling/clog of
the single stem.This
condition will invalidate
the object of PAHL.

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Figure 5: Process and Instrumentation Diagram

(Pressure Reduction System)

NODE-005: INSTRUMENT GAS SKID

005B

005A

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Node Guideword Cause/ Concern Recommendation Action

Party
OTHERS Overfill Possible overfill of
Conduct QRA study to
Condensate condensate closed drain
assess fire, gas dispersion NGPTC
Drain Tank. tank, likely to cause release
& explosion sterile area
of condensate and gas
and establishment of safe
(Gas blowby) into the
zone. This will be an input
atmosphere. into NGPTC operations
safety and emergency
Cold Vent response management
Stack system.
Conduct Fire and Gas
Gas disposal Flammable gas disposal explosion Risk and NGPTC
system into the atmosphere. Vulnerability Safety

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Audit/QRA to assess level

of vulnerability and
safety/emergency
readiness to worst case
scenarios
Review current final
pressure-
relieving/disposal design
(COLD VENT) method
and operations
philosophy if suitable for
continuity.
Note: The outcome of the
above audit/QRA study
will determine if mini-pilot
stack to burn vent gases
occasionally.

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15. APPENDIX 4: HAZOP WORK SHEET

NIGERIA GAS PROCESSING AND TRANSPORTATION COMPANY (NGPTC)

FEED REHABILITATION/UPGRADE OF DELTA IV METERING STATION PROJECT

NODE: 001 DESCRIPTION FILTER SEPARATOR

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 100 BARG 148 oc

NORMAL OPERATING ----------- 76 BARG 158 - 28oc GAS

CONDITION

Variable Deviation Possible Cause Consequences Control/Safe Guards Recommendations Actions /

Parameter Remarks
1.0 FLOW 1.0 NO/Lo 1.0 500-BLV-022 fully 1.0 No flow to filter 1.0 500 SDV- 001
w Flow closed separator/
2.0 500-BLV-022 V-500/heater 2.0 500-PDAH-001
Partially open
2.0 Low flow to filter 3.0 500-PAH-001,PDI-
3.0 Clogged/blocke separator/V-500 001,500-PSH-001
d filter due to dirt
3.0 Low flow to
heater

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Control/Safe Guards Recommendations Actions /

Parameter Remarks
4.0 Possible pressure
build and
System
shutdown

2,0 500-BLV-022 fully 2.0 No pressure to 2,0 500 SDV- 001

2.0 2.0 No closed filter separator/ V-
Pressure /low 500 and heater 2.1 500-PDAH-001
pressure 2.1 500-BLV-022
Partially open 2.1 Low pressure to 2.2 500-PAH-001,
filter PDI-001.500-PSH-
2.2 Clogged/blocke separator/V-500 001
d filter due to dirt 2.3 500-LAHH-001
2.2 Low pressure to
heater 2.4 500-LSHH-001

2.3 Possible pressure

build and
System
shutdown

3.0 High 3.0Clogged/blocke 3.0 Pressure 3.0 500 SDV- 001

Pressure d filter due to dirt build- 3.1 500-PDAH-001
up/possible high 3.2 500-PAH-001,
pressure inlet PDI-001,500-PSH-001

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Control/Safe Guards Recommendations Actions /

Parameter Remarks
line to v-500

4.0 High 4.0 500-BLV-013 fully 4.0 possible 4.0 ESD/500-PSHH-

pressure in closed condensate 002 Provide Tag no. for
V-500 formation/build up vessel below V-500
4.1 Operator’s in V-500,leading to 4.1 500-PSV-001
delay to bleed off high pressure in the
possible vessel 3.3 500-LAHH-001
condensate via 500- 3.1 System 3.4 500-BLV-005
BLV-012 & 500-BLV- shutdown 3.5 Use of SOP
011 3.6 Operator’s
3.2 Possible intervention
4.2 Failure of 500- condensate
LCV -001 build up in
condensate
collector
(provide
identification
tag no.), below
V-500

5.0 5.0 low level in 5.0 low level in 5.0 500-LALL-001,

low/high condensate condensate 500-LSLL-001
Level collector(provide collector (provide 5.1 500-LAH-
tag number) and V- tag number) and 001 &
500 possible trapped 500-LAHH-001

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Control/Safe Guards Recommendations Actions /

Parameter Remarks
(low level of liquid) 5.2 Use of SOP
5.1 Failure or in V-500. 5.3 Operator’s
malfunctioning of interventio
500-LCV or 500-LCV- 5.1 possible high n
002 liquid (condensate)
level in vessel.

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

HAZOP WORKSHEET

P&ID NO.NGPTC-W-156281 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 002A (10’’-PG-50120-D600; Inlet to Heater) DESCRIPTION HEATER H-400 & H-401

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 102 BARG 100 oc

NORMAL OPERATING ----------- 76 BARG 72 oc GAS

CONDITION

Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
1.0 FLOW 1.0 1.0 400-BLV-001 fully 1.0 No flow to heater 1.0 400-TG-001 Incorporate By-
No/Low Closed H-400 2.0 See burner pass line (Globe
Flow 2.0 Low flow to heater management and ball valve) on
2.0 400-BLV-001 3.0 Possible increase in system the 401-TCV 001.
partially open. temp. 3.0 401-TCV-001 Dual By-pass (Ball
4.0 low/no pressure to 4.0 Operator’s valve and Flow
instrument gas skid intervention Control Valve)
5.0 Use of SOP
2.0 2.0 low 2.0 400-BLV-001 fully 2.0No pressure to 2.0 400-PG-001
Pressure Pressure Closed heater H-400 2.1 Burner
2.1 400-BLV-001 2.1Low pressure to management
partially open. heater H-400 system

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
2.2 possible increase in 2.2 operator’s
temp intervention
2.3 low/no pressure to 2.3 use of SOP
instrument gas skid 2.4 401-TCV-001

NODE 002B - OUTLET OF H-400 (8’’-PG-40105-D600)

1.0 Flow 1.0 1.0 400-BLV-004 fully 1.0 No flow to 8’’-PG- 1.0 400-TG-001 Weam
NO/low Closed 40105-D600 header 2.0 See burner
Flow 2.0 400-BLV-004 2.0 low flow to 8’’-PG- management
partially open. 40105-D600 header system
3.0 401-TCV-001
4.0 Operator’s
intervention
5.0 Use of SOP
6.0 401-TVC-001
2.0 2.0 low 2.0 400-BLV-004 fully 2.0No pressure to 2.0 400-PG-001
Pressure Pressure Closed heater H-400 2.1 Burner
2.1Low pressure to management
2.1 400-BLV-004 heater H-400 system
partially open. 2.2 possible increase in 2.2 operator’s
temp intervention
2.3 low/no pressure to 2.3 Use of SOP
instrument gas skid 2.4 401-TCV-001

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
3.0 Temp. 3.0 3.0 Malfunctioning of 3.0 High temperature 3.0 400-TG-001
Low/High burner system
Temp management 3.1 401-TCV-001

3.1 No flow/pressure
to heater due to
BLV-004 fully
closed or partially
open

HEATER 401 – INLET AND OUTLET

Same as NODE 001A & 001B

P&ID NO. NGPTC-W-127881 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 003A (6’’-PG-30002-D600) DESCRIPTION PRESSURE REDUCTION SYSTEM

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 100BARG 50 oc

NORMAL OPERATING ----------- Inlet-76barg 18 oc GAS

CONDITION Out let : 18-

24bgarg

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks

1.0 Flow 1.0 1.0 Either 300-BLV- 1.0 No/ loss of flow to 1.0 Use of Standard 1.1 Develop and
No/low 001 or 300-BLV- 18”-PG-20001-B300 Operating Procedure implement
flow 002 inadvertently metering header (SOP) Specific SOP
fully closed and PSSR/checklist
1.1 No metering/loss 1.1 Use of Prestart Up to address possible
of production Safety Review (PSSR) Operator’s error
& checklist that could address
the identified
1.2 Operator’s possible cause of
intervention the deviation
2. SDV 001 fail 2.0 Loss of flow to the 2.0 Bypass valves and
open metering header isolations valves
2.1 No pressure/flow provided for the
resulting to no control valve
metering operations 2.1 PI001 provided
downstream of the
Launcher
3.0 300-BLV-007 3.0 Low flow on 3.0 300- PCV-005 & 300- 3.0 Consider to
or 18”-PG-30008-B300 PCV-006 install PSLL at the
300-BLV-011 fully and 18”-PG-20001- inlet of the PRS to
left opened B300 metering 3.1 Use of Standard recognize low low
header Operating Procedure (LL) condition and
(SOP) activate ESD to
3.1 Release of shutdown the

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks
flammable gas, 3.2 Use of Prestart Up system.
posing danger to Safety Review (PSSR) &
operators/facility. checklist

3.2 Possible 3.3 Operator’s

condensate build up intervention
due to low 3.4 PSL(to be
pressure/flow in the incorporated into
line design)

3.5 F&G system to

initiate system
shutdown based on
voting system

(Confirm if there is
existing F&G system
and that it is designed
to shut down the
system upon detection
of gas release based
on set point)
4.0 Possible 4.0 low flow on 18’’- 4.0 Visual inspection 4.0 Conduct an
rupture/leak from PG-30008-B300 & 18’’- 4.1 Risk Based intensive Risk
10’’ –PG-50020- PG-200001-B300 Inspection program Based Inspection

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks
B300 line due to 4.2 Preventive program
age of the line. maintenance e.g complying with
corrosion monitoring API RP 580 of the
program entire facility.

2. Pressure 2. No/Low 2.0 Either 300-BLV- 2.0 No /loss of 2.0 Use of Standard 2.0 Develop and
Pressure 001 or 300-BLV- pressure to Operating Procedure implement
002 inadvertently 18”-PG-20001-B300 (SOP) Specific SOP
fully closed metering header and PSSR/checklist
2.1 Use of Prestart Up to address possible
2.1 No metering/loss Safety Review (PSSR) Operator’s error
of production & checklist that could address
the identified
2.2 Operator’s possible cause of
intervention the deviation
2.1 Failure of SDV 2.0 Loss of pressure to 2.0 Bypass valves and
001 the metering header isolations valves
2.1 No pressure provided for the
resulting to no control valve
metering operations 2.1 PI001 provided
downstream of the
Launcher

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks
3.0 300-BLV-007 3.0 Low pressure in 3.0 300- PCV-005 & 300- 3.0 Consider to
or 18”-PG-30008-B300 PCV-006 install PSLL at the
and 18”-PG-20001- 3.1 Use of Standard inlet of the PRS to
300-BLV-011 fully
B300 metering Operating Procedure recognize low low
left opened header (SOP) (LL) condition and
3.2 Use of Prestart Up activate ESD to
3.1 Release of Safety Review (PSSR) & shutdown the
flammable gas, checklist system.
posing danger to 3.3 Operator’s
operators/facility. intervention
3.4 PSL (to be
3.2 Possible incorporated into
condensate build up design)
due to low F&G system to initiate
pressure/flow in the system shutdown
line based on voting system
(Confirm if there is
existing F&G system
and that it is designed
to shut down the
system upon detection
of gas release based
on set point)
4.0 Possible 4.0 low pressure in 4.0 PSLL to initiate 4.0 Conduct an
rupture/leak from 18’’-PG-30008-B300 & system shutdown intensive Risk

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks
10’’ –PG-50020- 18’’-PG-200001-B300 4.1 F&G system to Based Inspection
B300 line due to 4.1 Release of initiate system program
age of the line. flammable gas, shutdown based on complying with
posing danger to the voting system API RP 580 of the
facility (Confirm if there is entire facility.
4.2 Wastage of gas existing F&G system
and that it is designed 4.1 Review existing
to shut down upon F&G system
detection of gas) philosophy and
4.2 Visual inspection align to proposed
4.4 Preventive F&G system
maintenance e.g design.
corrosion monitoring
program

5.0 High 5.0 Excessive 5.0 Pressure build 5.0 Activation of PAH- Develop and
Pressure pressure due to up/High pressure 011,PAH-001, and implement
malfunctioning/ on 6’’-PG-30002- PSH-001 & PSH-011 Performance
failure of SDV- D600 and other 5.1 500-PSHH 001 on Standards for
001/ESD header and piping 10”-PG-50002-D600 Safety Critical
(e.g fail in stuck components inlet to filter Equipment(SCEs)
open position) Separator. e.g SDV-001/ESD,
5.2 Standard Operating PCV-005,PCV-006
Procedure(SOP) etc
5.3 Preventive

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions /

Parameter Remarks
maintenance of
Safety Critical
Equipment e.g
PT,PI,ESD,SDV etc

P&ID NO. NGPTC-W-127881 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 003B (6’’-PG-30003-D600) DESCRIPTION PRESSURE REDUCTION SYSTEM

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 100BARG 50 oc
NORMAL OPERATING ----------- Inlet-76barg 18 oc GAS
CONDITION Out let : 18-
24bgarg

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks

1.0 Flow 1.0 1.0 Either 300- 1.0 No /loss of flow to 6”- 1.0 Use of Standard 1.0 Develop and
No/low BLV-003 or 300- PG-30003-D600 Operating Procedure implement
flow BLV-004 1.1 No metering/loss of (SOP) Specific SOP
inadvertently production and PSSR/checklist
fully closed 1.2 No gas supply to 1.1 Use of Prestart Up to address possible
customer Safety Review (PSSR) & Operator’s error
checklist that could address
the identified
1.2 Operator’s possible cause of
intervention the deviation
3.0 300-BLV-012 3.0 Low flow to 3.0 300- PCV-003 & 300- 3.0 Consider to
or 6”-PG-30003-D600 PCV-004 install PSLL at the
300-BLV-008 fully 3.1 Release of 3.1 Use of Standard inlet of the PRS to
left opened flammable gas, posing Operating Procedure recognize low low
danger to (SOP) (LL) condition and
operators/facility. 3.2 Use of Prestart Up activate ESD to
Safety Review (PSSR) & shutdown the
checklist system.
3.3 Operator’s
intervention
3.4 PAL & PSL(to be
incorporated into

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Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks
design)
3.5 F&G system to
initiate system
shutdown based on
voting system upon
detection of gas
(Confirm if there is
existing F&G system
and that it is designed
to shut down the
system upon detection
of gas release based
on set point/voting
system)
3.6 PSV-012,ZLL-
012,PAL-012 on 10’’-
PG-30001-D600 header
4.0 Possible 4.0 low flow to 6’’-PG- 4.0 Visual inspection 4.0 Conduct an
rupture/leak from 30003-D600 4.1 Risk Based intensive Risk
10’’ –PG-50020- 4.1 No metering/loss of Inspection program Based Inspection
B300 line due to production 4.2 Preventive program
age of the line. 4.2 No gas supply to maintenance e.g complying with
customer corrosion monitoring API RP 580 of the

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks
program entire facility.

2. 2. No/Low 2.0 Either 300- 2.0 No/loss of pressure 2.0 Use of Standard 2.0 Develop and
Pressure Pressure BLV-003 or 300- to 6’’-PG- Operating Procedure implement
BLV-004 30003-D600 (SOP) Specific SOP
inadvertently and PSSR/checklist
fully closed 2.1 No metering/loss of 2.1 Use of Prestart Up to address possible
production Safety Review (PSSR) Operator’s error
2.2 No gas supply to & checklist that could address
customer the identified
2.2 Operator’s possible cause of
intervention the deviation
3.0 300-BLV-012 3.0 Low pressure to 6’’- 3.0 300- PCV-005 & 300- 3.0 Consider to
or PG-30003-D600 PCV-006 install PSL at the
300-BLV-008 fully 3.1 Use of Standard inlet of the PRS to
left opened 3.1 Release of Operating Procedure recognize low low
flammable gas, posing (SOP) (LL) condition and
danger to 3.2 Use of Prestart Up activate ESD to
operators/facility. Safety Review (PSSR) & shutdown the
checklist system.

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks
3.3 Wastage of gas 3.3 Operator’s
intervention
3.4 PAL & PSL (to be
incorporated into
design)
3.5 F&G system to
initiate system
shutdown based on
voting system & set
point.
(Confirm if there is
existing F&G system
and that it is designed
to shut down the
system upon detection
of gas release based
on set point)
3.6 PSV-012,ZLL-
012,PAL-012 on 10’’-
PG-30001-D600 header
4.0 Possible 4.0 low to headers and 4.0 PSLL to initiate 4.0 Conduct an
rupture/leak from 6’’ -PG-30003-D600 system shutdown intensive Risk
10’’ –PG-50020- 4.1 Release of 4.1 F&G system to Based Inspection

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks
B300 line due to flammable gas, posing initiate system program
age of the line. danger to the facility shutdown based on complying with
4.2 Wastage of gas voting system API RP 580 of the
(Confirm if there is entire facility.
existing F&G system 4.1 Review existing
and that it is designed F&G system
to shut down the philosophy and
system upon detection align to proposed
of gas) F&G system
design.
4.2 Visual inspection
4.4 Preventive
maintenance e.g
corrosion monitoring
program
5.0 High 5.0 Excessive 6.0 High pressure on 6’’- 4 Activation of PAH- Develop and
Pressure pressure due to PG-30003-D600 011,PAH-001, and implement
malfunctioning/ PSH-001 & PSH-011 Performance
failure of SDV- 4.3 500-PSHH 001 on Standards for
002/ESD 10”-PG-50002-D600 Safety Critical
(e.g fail in stuck inlet to filter Equipment(SCEs)
open position) Separator. e.g SDV-001/ESD,
4.4 Preventive PCV-005,PCV-006

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Paramete /
r Remar
ks
maintenance of etc
Safety Critical
Equipment e.g
PT,PI,ESD,SDV etc

P&ID NO. NGPTC-W-127881 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 003C (6’’-PG-30004-D600) DESCRIPTION PRESSURE REDUCTION SYSTEM

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 100BARG 50 oc

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

NORMAL OPERATING ----------- Inlet-76barg 18 oc GAS

CONDITION Out let : 18-
24bgarg

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Parameter /
Remar
ks
1.0 Develop and
1.0 Flow 1.0 1.0 Either 300- 1.0 No/loss of flow to 1.0 Use of Standard implement
No/low BLV-005 or 300- 6”-PG-30004-D600 Operating Procedure Specific SOP
flow BLV-006 header. (SOP) and PSSR/checklist
inadvertently to address possible
fully closed 1.1 possible loss of 1.1 Use of Prestart Up Operator’s error
production/supply to Safety Review (PSSR) that could address
customer & checklist the identified
possible cause of
1.2 Operator’s the deviation
intervention
3.0 300-BLV- 2.0 Low flow to 3.0 300- PCV-001 & 300- 3.0 Consider to
013 or 6’’-PG-30004-D600 PCV-002 install PAL & PSL at
300-BLV-009 the inlet of the PRS
fully left 3.1 Release of 3.1 Use of Standard to recognize low
opened flammable gas, posing Operating Procedure low (LL) condition
danger to (SOP) and activate ESD
operators/facility. to shutdown the
3.2 Use of Prestart Up system.

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Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Parameter /
Remar
ks
Safety Review (PSSR) &
checklist
3.3 Operator’s
intervention
3.4 PAL & PSL to be
incorporated into
design to initiate
system shutdown at
low/low low
pressure/flow
condition
3.5 F&G system to initiate
system shutdown based
on voting system
(Confirm if there is
existing F&G system and
that it is designed to
shut down the system
upon detection of gas)

4.0 Possible 3.0 low flow to 4.0 Visual inspection of 4.0 Conduct an
rupture/leak 6’’-PG-30004-D600 AG lines intensive Risk
from 4.1 Risk Based Inspection Based Inspection

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Parameter /
Remar
ks
10’’ –PG-50020- program program
B300 line due to 4.2 Preventive complying with
age of the line. maintenance e.g API RP 580 of the
corrosion monitoring entire facility.
program

4.3 PAL & PSL to be

incorporated into design
to initiate system
shutdown at low/low low
pressure/flow condition

2. Pressure 2. 2.0 Either 300- 5 No/ loss of pressure 2.0 Use of Standard 2.0 Develop and
No/Low BLV-005 or 300- to 6”-PG- Operating Procedure implement
Pressure BLV-006 30003-D600 metering (SOP) Specific SOP
inadvertently header and PSSR/checklist
fully closed 2.1 Use of Prestart Up to address possible
2.1 No metering/loss of Safety Review (PSSR) Operator’s error
production & checklist that could address
the identified
2.2 Operator’s possible cause of
intervention the deviation

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Parameter /
Remar
ks
3.0 300-BLV- 3.0 Low pressure to 3.0 300- PCV-003 & 300- 3.0 Consider to
0013 or 6”-PG-30004-D600 PCV-004 install PAL & PSL at
300-BLV-009 or 3.1 Use of Standard the inlet of the PRS
BLV-010 on 3.1 Release of Operating Procedure to recognize low
10’’-PG-30001- flammable gas, posing (SOP) low (LL) condition
D600 fully left danger to 3.2 Use of Prestart Up and activate ESD
opened operators/facility. Safety Review (PSSR) & to shutdown the
checklist system.
3.2 Wastage of gas 3.3 Operator’s
intervention
3.4 PSL& PAL to be
incorporated into
design to initiate
system shutdown at
low/low low
pressure/flow
condition
4.0 Possible 4.0 Low pressure to 4.0 PSLL to initiate system 4.0 Conduct an
rupture/leak 6”-PG-30004-D600 shutdown intensive Risk
from and 4.1 F&G system to initiate Based Inspection
10’’ –PG-50020- 10’’ –PG-30001-D600 system shutdown based program
B300 line due to header. on voting system and set complying with
age of the line. 4.1 possible loss of point. API RP 580 of the

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendations Actions

Parameter /
Remar
ks
production/supply to (Confirm if there is entire facility.
customer existing F&G system and 4.1 Review existing
that it is designed to F&G system
4.2 Release of shut down the system philosophy and
flammable gas, posing upon detection of gas) align to proposed
danger to the facility 4.2 Visual inspection of F&G system
process AG process design.
4.3Wastage of gas piping
4.4 Preventive
maintenance e.g
corrosion monitoring
program
5.0 High 5.0 Excessive 5.0 High pressure on 6’’- 5.0 Activation of PAH- Develop and
Pressure pressure due to PG-30004-D600 013,PAH-003, and implement
malfunctioning/ PSH-003 & PSH-013 Performance
failure of SDV- Standards for
003/ESD 5.1 Preventive Safety Critical
(e.g fail in stuck maintenance of Equipment (SCEs)
open position) Safety Critical e.g SDV-001/ESD,
Equipment e.g PCV-003,PCV-004
PT,PI,ESD,SDV etc etc

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

P&ID NO. NGPTC-W-127881 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 003 D (6’’-PG-30004-D600) DESCRIPTION PRESSURE REDUCTION SYSTEM

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 100BARG 50 oc
NORMAL OPERATING ----------- Inlet-76barg 18 oc GAS
CONDITION Out let : 18-
24bgarg

Variable Deviation Possible Cause Consequences Safeguard/Control Recommendatio Actions

Parameter ns /
Remar
ks

1.0 Flow 1.0 1.0 300-BLV-002 1.0 No/loss of flow to 1.0 Use of Standard 1.0 Develop and
No/low inadvertently to 18”-PG-20001- Operating Procedure implement
flow fully closed B300 header. (SOP) Specific SOP
(when only and
6’’-PC-30002- 1.1 No metering 1.1 Use of Prestart Up PSSR/checklist to
D600 line is on 1.2 No gas supply to Safety Review (PSSR) & address possible
stream.) customer checklist Operator’s error
that could
1.2 Operator’s intervention address the
identified
possible cause of

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the deviation
2.0 300-BLV-002 2.0 low flow to 2.0 Use of Standard 2.0 Consider to
inadvertently 18”-PG-20001-B300 Operating Procedure install PAL & PSL
partially open header. (SOP) at the inlet of the
(when only PRS to recognize
6’’-PC-30002- 2.1 possible loss of 2.1 Use of Prestart Up low low (LL)
D600 line is on production/supply to Safety Review (PSSR) condition and
stream). customer & checklist activate ESD to
shutdown the
2.2 Operator’s intervention system.
2.3 PAL & PSL to be
incorporated into
design to initiate
system shutdown at
low/low low
pressure/flow condition

3.0 300-BLV-011 3 Low flow to 3.0 300- PCV-003 & 300- 3.0 Consider to
or 18’’-PG-20001-B300 PCV-004 install PAL & PSL
300-BLV-007 3.1 Release of 3.1 Use of Standard at the inlet of the
fully left opened flammable gas, posing Operating Procedure PRS to recognize
danger to (SOP) low low (LL)
operators/facility. 3.2 Use of Prestart Up condition and
Safety Review (PSSR) & activate ESD to
checklist shutdown the
3.3 Operator’s intervention system.
3.4 PAL & PSL to be

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

incorporated into
design to initiate
system shutdown at
low/low low
pressure/flow condition
3.5 F&G system to initiate
system shutdown based
on voting system and set
point.
(Confirm if there is existing
F&G system and that it is
designed to shut down the
system upon detection of
gas)
4.0 Possible 4.0 low flow to 4.0 Visual inspection of AG 4.0 Conduct an
rupture/leak 18’’-PG-20001-B300 lines intensive Risk
from 4.1 Risk Based Inspection Based Inspection
10’’ –PG-50020- 4.1 Release of program program
B300 line due to flammable gas, posing 4.2 Preventive complying with
age of the line. danger to maintenance e.g API RP 580 of the
operators/facility corrosion monitoring entire facility.
program
4.2 Wastage of gas
4.3 PAL & PSL to be
4.3 No metering/no incorporated into design
supply to customer to initiate system
shutdown at low/low low

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pressure/flow condition
4.4 F&G system to initiate
system shutdown based
on voting system and set
point.
(Confirm if there is existing
F&G system and that it is
designed to shut down the
system upon detection of
gas)

2. Pressure 2. 1.0 300-BLV-002 3.0 No/ loss of pressure 1.0 Use of Standard 1.0 Develop and
No/Low inadvertently to 18”-PG- Operating Procedure implement
Pressure fully closed 20001-B300 header. (SOP) Specific SOP
(when only 3.1 No metering 1.1 Use of Prestart Up and
6’’-PC-30002- 3.2 No gas supply to Safety Review (PSSR) & PSSR/checklist to
D600 line is on customer checklist address possible
stream. 1.2 Operator’s intervention Operator’s error
that could
address the
identified
possible cause of
the deviation
2.1 Failure of 2.0 Loss of pressure to 2.0 Use of Standard
SDV 002 6’’-PG-30003-D600 Operating Procedure
(SOP)
2.1 No pressure 2.1 Use of Prestart Up

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resulting to no Safety Review (PSSR)

metering operations & checklist
2.2 Operator’s intervention
3.0 300-BLV-007 3.0 Low pressure to 3.0 300- PCV-003 & 300- 3.0 Consider to
or 18”-PG-30008-B300 PCV-004 install PAL & PSL
300-BLV-011 and 18”-PG-20001- at the inlet of the
fully left opened B300 metering header 3.1 Use of Standard PRS to recognize
Operating Procedure low low (LL)
3.1 Release of (SOP) condition and
flammable gas, posing 3.2 Use of Prestart Up activate ESD to
danger to Safety Review (PSSR) & shutdown the
operators/facility. checklist system.
3.3Operator’s intervention
3.3 Wastage of gas 3.4 PSL& PAL to be
3.4 No metering/supply incorporated into design
of gas to to initiate system
customers. shutdown at low/low low
pressure/flow condition
3.5 F&G system to initiate
system shutdown based
on voting system and set
point.
(Confirm if there is existing
F&G system and that it is
designed to shut down the
system upon detection of
gas)

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4.0 Possible 4.0 Low pressure to 4.0 PSLL to initiate system 4.0 Conduct an
rupture/leak 18”-PG-20001-B300 shutdown intensive Risk
from header. 4.1 F&G system to initiate Based Inspection
10’’ –PG-50020- 4.1No metering/ gas system shutdown program
B300 or any supply to customer based on voting system complying with
other line due to due to system (Confirm if there is existing API RP 580 of the
age of the line. shutdown F&G system and that it is entire facility.
designed to shut down the 4.1 Review
4.2 Release of system upon detection of existing F&G
flammable gas, posing gas) system
danger to the facility 4.2 Visual inspection of philosophy and
process AG process piping align to
4.3Wastage of gas 4.3 Preventive proposed F&G
maintenance e.g system design.
corrosion monitoring
program
5.0 High 5.0 Excessive 5.0 High pressure to 5.0 Activation of PAH- Develop and
Pressure pressure due to 18’’-PG-20001-B300 011,PAH-001, and PSH-001 implement
malfunctioning/ & PSH-011 Performance
failure of SDV- 5.1 Preventive Standards for
001/ESD maintenance of Safety Safety Critical
(e.g fail in stuck Critical Equipment e.g Equipment
open position) PT,PI,ESD,SDV etc (SCEs)e.g
SDV/ESD,PCVs
etc

Temp. 6.0 High 6.0 Failure of 6.0 High temperature 6.0 401-TCV-001 will

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Temp Heater on 18’’-PG- regulate high temp.

Temperature 20001-B300 header
Regulating
panel

HAZOP WORKSHEET

P&ID NO.NGPTC-W-125885 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 004 (18’’-PG-20002-B300) DESCRIPTION METERING SYSTEM

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FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN 50 BARG 50 oc
NORMAL OPERATING ----------- 18-24bgarg 15 oc GAS
CONDITION

Variable Deviation Possible Cause Consequences Control/Safe Recommendations Actions /

Parameter Guards Remarks
1.0 Flow 1.0 NO/Low 1.0 200-SDV-002 shut 1.0 No flow to 1.0 200-FAL-002
Flow down due to header/ power plant 2.0 200-SDV-022
undesired 3.0 200-FQI-
pressure/flow 002/200-FUA-
inlet of metering 2.0 Low flow to 002
system header/ power plant 4.0 200-SDV-022
2.0 200-BLV-002 5.0 200-ZSHL-002
inadvertently left
fully open
2.0 High or 2.0 Possible high 2.0 High/more flow 2.0 200-FAH-002
more flow flow from pressure to header/power 2.1 200-FUA-002
reduction skid plant 2.2 200-SDV-022
2.0 2.0 No/low 2.0 200-SDV-002 2.0 No pressure to 2.0 200-PSHL-002
Pressure pressure shut down possibly header/power plant 2.1 200-PAL-001
due to undesired 2.2 200-SDV-022
pressure/flow, 2.1 Low pressure to
from/inlet of header/ power
metering system plant
2.1 200-BLV-002
inadvertently left

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Variable Deviation Possible Cause Consequences Control/Safe Recommendations Actions /

Parameter Guards Remarks
fully open
3.0 High 3.0 possible high 3.0 High pressure on 3.0 200-PAH-001 Consider to design
pressure pressure from 18’’-PG-20002-B300 & 3.1 200-PAL-001 alarm system to
pressure reduction 18’’-PG-20004-B300 3.2 200-SDV-003 include PAHH &
skid headers PALL. This will allow
operator’s
intervention rather
than immediate
system shutdown
whenever PAH &
PAL comes up.
Note: NGPTC
should review
existing operation
& control
philosophy to
confirm
acceptance of
‘’ shut down
system upon
detection of PAH
& PAL alarm.
3.0 200-TAL-001 &
3.0 Temp 3.0 3.0 Failure of Heater 3.0 High 200-TSL-001
Low/High Temperature temperature on

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Variable Deviation Possible Cause Consequences Control/Safe Recommendations Actions /

Parameter Guards Remarks
Temp Regulating panel headers 3.1 401- TCV-001

NODE: 004B (18’’-PG-20003-B300)

1.0 200-SDV-001 shut
1.0 Flow 1.0 No/Low down due to 1.0 No flow to 1.0 200-FAL-001
Flow undesired header/ power plant 2.0 200-SDV-012
pressure/flow inlet of 3.0 200-FQI-002/200-
metering system 2.0 Low flow to FUA-001
header/ power plant 4.0 200-SDV-012
2.0 200-BLV-001 5.0 200-ZSHL-001
inadvertently left
fully open

2.0 High or 2.0 Possible high 2.0 High/more flow 2.0 200-FAH-001
more flow flow from pressure to header/power 2.1 200-FUA-001
reduction skid plant 2.2 200-SDV-012
2.0 200-SDV-001 2.0 No pressure to
2.0 2.0 No/low shut down possibly header/power plant 2.0 200-PSHL-001
Pressure pressure due to undesired 2.1 200-PAL-001
pressure/flow, 2.1 Low pressure to 2.2 200-SDV-012
from/inlet of header/ power
metering system plant
2.1 200-BLV-001
inadvertently left
fully open

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Variable Deviation Possible Cause Consequences Control/Safe Recommendations Actions /

Parameter Guards Remarks

3.0 High 3.0 possible high 3.0 High pressure on 3.0 200-PAH-001 Consider to design
pressure pressure from 18’’-PG-20002-B300 & 3.1 200-PAL-001 alarm system to
pressure reduction 18’’-PG-20004-B300 3.2 200-SDV-003 include PAHH &
skid headers PALL. This will allow
operator’s
intervention rather
than immediate
system shutdown
whenever PAH &
PAL comes up.
Note: NGPTC
should review
existing operation
& control
philosophy to
confirm
acceptance of
‘’ shut down
system upon
detection of PAH
& PAL alarm.

3.0 Temp. 3.0 3.0 Failure of Heater 3.0 High 3.0 200-TAL-001 &
Low/High Temperature temperature on 200-TSL-001

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Variable Deviation Possible Cause Consequences Control/Safe Recommendations Actions /

Parameter Guards Remarks
Temp Regulating panel headers 3.1 401- TCV-001
on heater

P&ID NO.NGPTC-W-129991 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 005 A (2’’-IG-40104-D600) DESCRIPTION INSTRUMENT GAS SKID

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

DESIGN
NORMAL OPERATING ----------- GAS
CONDITION

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
1.0 Flow 1.0 No 1.0 500-BLV-027 fully 1.0 No flow to the 1.0 Use of SOP 1.0 Provide
/low Flow closed common header 2.0 PSSR/checklist tag/no. for
2.0 Check valve 2.0 Low flow to 3.0 Operator’s instrument buffer
wrongly installed. pneumatic driven intervention. tank.
3.0 500-BLV-027 Safety 4.0 Instrument Buffer
Partially open Instrumented tank (provide 2.0 Consider to
4.0 Check valve system/gas tag no. for separate PAH &
stuck in partially equipment( instrument PAL from 500-
open position. Generator. filter buffer tank). PAHL-015 and
5.0 Clogged filter F-2 separator.PRS etc) 5.0 PAHL 015 design to be
independent to
3.0 System shutdown avoid common
and loss of production. cause failure and
ensure reliability.
2.0 2.0 2.0 500-BLV-027 fully 2.0 No pressure to the 3.0 Use of SOP 1.0 Provide
Pressure No/low closed common header 3.1 PSSR/checklist tag/no. for
pressure 2.1 Check valve 2.1 Low pressure to 3.2 Operator’s instrument buffer
wrongly installed. pneumatic driven intervention. tank.
2.2 500-BLV-027 Safety Instrumented 3.3 Instrument
Partially open system/gas equipment Buffer tank (provide 2.0 Consider to
2.3 Check valve ( e.g Generator. filter tag no. for separate PAH &
stuck in partially separator.PRS etc) instrument buffer PAL from 500-
open position. 2.2 possible System tank). PAHL-015 and
shutdown and loss of 3.4 PAHL 015 design to be
2.4 Clogged filter F-2 production. independent to

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
avoid common
cause failure and
ensure reliability.

3.0 High 3.0 Failure of 3.0 Possible 3.0 Alarm system

pressure 500-PCV-002. Overpressure on the 3.1 500-PSV-012
buffer tank. 3.2 Operator’s
Intervention
3.3 SOP
4.0 Revers 4.0 500-BLV-028 fully 4.0 Reverse flow 4.0 500-CKV-002
e Flow closed

OTHERS 1.0 1.0 500-BLV-023 and 1.0 Possible hydrate 1.0 Use of SOP
Mixture of 500-BLV-025 left formation. 2.0 Use of PSSR &
1. Cold & cold gas fully open 2.0 Possible equipment checklist
Hot gas and hot malfunctioning 3.0 Operator’s
mixture gas /damage. intervention
together,
feeding
SIS/
equipmen
t

2.0 2.0 Drain 2.0 Possible overfill 2.0 Possible overfill of SOP, dipstick and Refer: 2005 BP

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
Condensa tank of closed closed condensate evacuate of Texas Refinery
te drain overfill condensate tank tank and release of condensate tank explosion was
tank and release of condensate/gas with a vacuum caused by overfill
condensate/gas cloud truck. of blow down
cloud likely to cause (carryover/process drum which was
serious process deviation) likely to ignited by
safety challenges to cause serious process operations truck
operators/facility safety challenges to in the plant.
operators/facility. E.g
fire & gas explosion Conduct QRA
study to assess fire
and gas
dispersion &
explosion sterile
area. This will be
an input into
NGPTC
operations safety
and emergency
response
management
system.

3.0 Conduct Fire and

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
Cold Vent Release of flammable gas/condensate via cold vent header to the cold vent Gas explosion Risk
Header/ stack into the atmosphere is quite dangerous. It is a process safety concern and Vulnerability
Stack that has to be reviewed and management decision taken based on the Safety Audit/QRA
outcome. A technical Safety and Loss Prevention Engineering study is advised. to assess level of
vulnerability and
safety/emergenc
y readiness to
worst case
NOTE: scenarios
Ref: 2005 BP Texas Refinery Explosion caused by overfilled tower and released 3.1. Review
via a cold vent stack (Blow down drum).The flammable liquid and gas vapour current final
released was ignited by operator’s truck which exploded and destroyed the pressure-
Refinery and many fatalities were recorded. relieving/dispo
sal design
Consequence of the explosion: 15 people Killed, 180 Injured (COLD VENT)
method and
operations
philosophy if
suitable for
continuity.
Note: The
outcome of
the above
audit/QRA
study will

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 HAZOP and Operability Study Report for FEED for the Rehabilitation/Upgrade of Delta IV Metering Station

Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
determine if
mini-pilot stack
to burn vent
gases
occasionally.

P&ID NO.NGPTC-W-129991 INSTALLATION GAS METERING STATION DATE 22-03-2018

NODE: 005B (2’’-IG-50001-D600) DESCRIPTION INSTRUMENT GAS SKID

FLOW PRESSURE TEMPERATURE (0C) COMPOSITION

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DESIGN
NORMAL OPERATING ----------- GAS
CONDITION

Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
1.0 Flow 1.0 No /low 1.0 500-BLV-023 fully 1.0No flow to the 1.0 Use of SOP 1.0 Provide
Flow closed common header 2.0 PSSR/checklist tag/no. for
2.0 Check valve 2.0 Low flow to 3.0 Operator’s instrument buffer
wrongly installed. pneumatic driven intervention. tank.
3.0 500-BLV-023 Safety Instrumented 4.0 Instrument Buffer
Partially open system/gas tank (provide 2.0 Consider to
4.0 Check valve equipment( tag no. for separate PAH &
stuck in partially Generator. filter instrument PAL from 500-
open position. separator.PRS etc) buffer tank). PAHL-015 and
5.0 Clogged filter F-1 5.0 PAHL 015 design to be
3.0 System independent to
shutdown and loss avoid common
of production. cause failure and
ensure reliability.
2.0 2.0 No/low 2.0 500-BLV-023 fully 2.0 No pressure to 4.0 Use of SOP 1.0 Provide
Pressure pressure closed the common 4.1 PSSR/checklist tag/no. for
2.1 Check valve header 3.2 Operator’s instrument buffer
wrongly installed. 2.1 Low pressure to intervention. tank.
2.2 500-BLV-023 pneumatic driven 3.3 Instrument
Partially open Safety Instrumented Buffer tank (provide 2.0 Consider to

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
2.3 Check valve system/gas tag no. for separate PAH &
stuck in partially equipment ( e.g instrument buffer PAL from 500-
open position. Generator. filter tank). PAHL-015 and
separator.PRS etc) 3.4 PAHL 015 design to be
2.5 Clogged filter F-1 2.2 possible System independent to
shutdown and loss avoid common
of production. cause failure and
ensure reliability.

3.0 High 3.0 Failure of 3.0 Possible 3.0 Alarm system

pressure 500-PCV-001. Overpressure on the 4.1 500-PSV-012
buffer tank. 3.2 Operator’s
Intervention
3.3 SOP
5.0 Reverse 4.0 500-BLV-024 fully 4.0 Reverse flow 4.0 500-CKV-001
Flow closed

OTHERS 1.0 Mixture 2.0 500-BLV-023 and 6.0 Possible hydrate 1.0 Use of SOP
of cold gas 500-BLV-025 left formation. 2.0 Use of PSSR &
1. Cold & and hot fully open 7.0 Possible checklist
Hot gas gas equipment 3.0 Operator’s
mixture together, malfunctioning intervention
feeding /damage.
SIS/

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
equipment

2.0 2.0 Drain 2.0 Possible overfill of 2.0 Possible overfill SOP, dipstick and Refer: 2005 BP
Condensat tank closed condensate of closed evacuate of Texas Refinery
e drain overfill tank and release of condensate tank condensate tank explosion was
tank condensate/gas and release of with a vacuum caused by overfill
cloud likely to cause condensate/gas truck. of blow down
serious process cloud drum which was
safety challenges to (carryover/process ignited by
operators/facility deviation) likely to operations truck
cause serious in the plant.
process safety
challenges to Conduct QRA
operators/facility. study to assess fire
E.g fire & gas and gas
explosion dispersion &
explosion sterile
area. This will be
an input into
NGPTC
operations safety
and emergency
response
management
system.

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks

3.0 Conduct Fire and

Cold Vent Release of flammable gas/condensate via cold vent header to the cold vent Gas explosion Risk
Header/ stack into the atmosphere is quite dangerous. It is a process safety concern and Vulnerability
Stack that has to be reviewed and management decision taken based on the Safety Audit/QRA
outcome. A technical Safety and Loss Prevention Engineering study is advised. to assess level of
vulnerability and
safety/emergenc
y readiness to
worst case
NOTE: scenarios
Ref: 2005 BP Texas Refinery Explosion caused by overfilled tower and released 3.2. Review
via a cold vent stack (Blow down drum).The flammable liquid and gas vapour current final
released was ignited by operator’s truck which exploded and destroyed the pressure-
Refinery and many fatalities were recorded. relieving/dispo
sal design
Consequence of the explosion: 15 people Killed, 180 Injured (COLD VENT)
method and
operations
philosophy if
suitable for
continuity.
Note: The
outcome of

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Variable Deviation Possible Cause Consequences Control/Safe Recommendation Actions /

Parameter Guards s Remarks
the above
audit/QRA
study will
determine if
mini-pilot stack
to burn vent
gases
occasionally.

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