FEED Study for Tambakboyo Field Development RFQ FOR SAFETY ...

FEED Study for Tambakboyo Field Development

RFQ FOR SAFETY STUDIES (FERA/QRA)

Client : Saka Indonesia Pangkah Limited

Contract No. / WO No. : 4600012802 (Provision of Engineering

Services for Pangkah Development)

Document No. : TBD-TJ-G10-LC-RQ-9002

Revision Date Description Originator Checker Approver Client

Approval

B 20-09-2021 Issued for Information STF ADM IMS/BAS

B1 28-10-2021 Re-Issued for Information STF ADM IMS/BAS

AAnugrahesa

Stamp

ImamS

Stamp


TBD-TJ-G10-LC-RQ-9002_Rev. B1 Page 2 of 12

RECORD OF REVISION

Rev. No.

Section Page Company Comment Incorporated

(Y/N) Contractor Response

B Attachment ToR QRA

17

Add in Section 3.4:

- Subsea &Umbilical Cable (Electrical Power & FO) Risk Calculation

- Dropped Object Risk Calculation

Y Incorporated



TABLE OF CONTENT

RECORD OF REVISION ............................................................................................................ 2

TABLE OF CONTENT ................................................................................................................ 3

1. INTRODUCTION ................................................................................................................. 5

Project Background ..................................................................................................... 5 1.1

Objectives ................................................................................................................... 6 1.2

References.................................................................................................................. 6 1.3

Abbreviation ................................................................................................................ 6 1.4

Definition of Terms ...................................................................................................... 7 1.5

2. SCOPE OF WORK .............................................................................................................. 8

FERA Study ................................................................................................................ 8 2.1

QRA Study .................................................................................................................. 8 2.2

3. SCHEDULE ......................................................................................................................... 9

4. PROPOSAL ....................................................................................................................... 10

Technical Proposal .................................................................................................... 10 4.1

Commercial Proposal ................................................................................................ 10 4.2

5. ACCEPTANCE OF SERVICES ......................................................................................... 11

Report Content .......................................................................................................... 11 5.1

Service Completion ................................................................................................... 11 5.2

6. ATTACHMENTS ................................................................................................................ 12



LIST OF TABLES

Table 1 List Specification and Documentation ............................................................................ 6

LIST OF FIGURES

Figure 1 Tambakboyo Platform (WHP-E) Location ..................................................................... 5



1. INTRODUCTION

Project Background 1.1

SAKA Indonesia Pangkah Limited / SIPL (herein referred as COMPANY) has been

commissioned to undertake the operator of Ujung Pangkah Block in East Java since January

2014 from HESS. The Ujung Pangkah field is located offshore of the north coast of East Java

approximately 35 km north of Gresik, East Java, Indonesia; lies adjacent to the Bengawan Solo

river delta.

The Tambakboyo Field is oil producing field with some associated gas. The Tambakboyo Field is located at 10 km north of Ujung Pangkah Field, in Gresik, East Java with water depths of approx. 30 m from Mean Sea Level (MSL). The location map for Tambakboyo Field is shown below.

Figure 1 Tambakboyo Platform (WHP-E) Location

The production facility at Tambakboyo Field will consist of one (1) unmanned Wellhead

Platform (WHP-E) with minimum facilities installed. WHP-E will be connected by subsea

pipelines and cables to existing offshore platform (WHP-B, CPP and AUP).

The WHP-E Tambakboyo platform is designed to accommodate the concept of gradual

development (phasing) with the first phase is installation of 3 wellheads and the next phase,

another 4 wellheads. WHP-E will be designed to accommodate activities such as well

intervention and well maintenance using the rig less method, namely with Hydraulic Work Over

Units (HWU).

The production results from the Tambakboyo Field well will be sent to the production facility in the WHP-B platform for further processing at the CPP platform and commingled with the production from other wells at Ujung Pangkah Fields to the Onshore Processing Facility (OPF) via 18” export pipeline (40 km length).



Tambakboyo Development FEED can be summarized as below.

Wellhead Platform- E (WHP-E) and associate facilities;

Subsea pipeline from WHP-E to WHP-B;

Subsea Umbilical for Powerline and Fiber Optic Cable penetrate and stop on WHP-B

Platform, then continue routing to AUP via cable tray;

Tie-in and modification of existing facilities (WHP-B, CPP and AUP) to accommodate Tambakboyo’s production.

Objectives 1.2

This request for quotation defines the minimum requirements of scope of work and services for

the following studies:

1. FERA

2. QRA

Any deviations to this request for quotation shall be listed by the THIRD PARTY with reference to the document clause in their quotation. In absence of any deviations, it will be assumed that the THIRD PARTY is in full compliance to the stated requirements.

References 1.3

All the Project Documents are listed below shall be formed as Applicable Documents. Unless otherwise specified, the latest edition / revision shall be used.

Table 1 List Specification and Documentation

Document Number Title

- Term of Reference for FERA

- Term of Reference for QRA

Abbreviation 1.4

The following abbreviations are used for purpose of this document:

FERA : Fire and Explosion Risk Assessment

HAZOP : Hazard and Operability

HAZID : Hazard Identification

IRPA : Individual Risk per Annum

LSIR : Location Specific Individual Risk

P&ID : Piping and Instrumentation Diagram

PFD : Process Flow Diagram

PLL : Potential Loss of Life

QRA : Quantitative Risk Assessment



UFD : Utility Flow Diagram

WHP : Wellhead Platform

Definition of Terms 1.5

The following definitions are used for purpose of this document:

COMPANY : Saka Indonesia Pangkah Limited (SIPL)

CONTRACTOR : PT TRIPATRA ENGINEERING

VENDOR : Party which supplies equipment specified and ordered by CONTRACTOR (or COMPANY)

MANUFACTURER : Party which manufactures equipment/materials specified and ordered by CONTRACTOR (or COMPANY)



2. SCOPE OF WORK

FERA Study 2.1

SUBCONTRACTOR shall have sufficient skill and experience to perform the activities below:

Selecting the scenarios of HAZOP and HAZID.

Prepare the study in liaison with the CONTRACTOR

Ensure the full compliance as per Term of Reference

Identify the hazardous substances (flammable) relevant to possible accidental releases from equipment items of the new facilities

Identify the isolatable section of the new facilities

Define a representative set of release point locations

Characterize the release conditions for each release point

Calculate the discharge rate for a number of leak sizes for each release point

Calculate the release frequency for all the identified release cases

Identify possible outcome scenarios based on typical event trees

Assess the vulnerability of equipment threshold calculations and human fatalities thresholds

Assess the consequence of fire and explosion scenarios

Recommend the implementation of risk reduction measures

QRA Study 2.2

SUBCONTRACTOR shall have sufficient skill and experience to perform the activities below:

Evaluating FERA Study and prepare several data and information.

Prepare the study in liaison with the CONTRACTOR

Ensure the full compliance as per Term of Reference

Calculate of generic failures using part count analysis

Calculate of process specific and human failures using fault tree analysis

Calculate of other failures frequency using empirical data from references

Simulation of gas dispersion and liquid spills as well as fire, explosion or toxic (if any) contour and extent using consequence analysis software

Combining the frequency assessment results and consequence analysis using event tree analysis and aggregate the risk to provide fire, explosion and toxic risk

Calculating IRPA (Individual Risk per Annum), LSIR (Location Specific Individual Risk), PLL (Potential Loss of Life) and FN Curve (if any).

Assess the vulnerability of equipment threshold calculations and human fatalities thresholds

Assess the consequence of fire and explosion scenarios

Recommend the implementation of risk reduction measures



3. SCHEDULE

CONTRACTOR provide preliminary schedule for workshop to SUBCONTRACTOR, as follow:

FERA and QRA Studies, the preliminary schedule as follows:

No. Task IFR AFD

1 FERA Study 29 October 2021 12 November 2021

2 QRA Study 05 November 2021 19 November 2021



4. PROPOSAL

The proposal shall be identified as clearly as possible of the proposed works. The proposal by THIRD PARTY to be submitted should comprise of two parts, technical and commercial proposal.

Technical Proposal 4.1

The technical proposal one (1) original and one (1) copy are to be submitted to CONTRACTOR. The technical proposal should cover minimum but not limited to the following:

• Covering Letter.

• THIRD PARTY organizations profile and capability.

• Proposed schedule for execution the works.

• Professional resumes of proposed personnel.

• Copy of license ownership of the proposed software.

• HSE & Quality assurance plan.

• Detail deliverable list

• Detail of previous similar work has been carried out

• Any other information which bidder feels can give them a professional edge over other competitors.

Commercial Proposal 4.2

The commercial proposal one (1) original and one (1) copy are to be submitted to CONTRACTOR. Commercial Prices for each works shall be broken down separately for each studies listed in Section 1.2 above. The commercial proposal shall be submitted in a sealed envelope marked “CONFIDENTIAL”

The detail price shall also include insurance premiums, taxes and other obligations for the overall facilitation works.



5. ACCEPTANCE OF SERVICES

Report Content 5.1

Report shall be provided in 2 (two) cycles, i.e. Issue for Review (IFR) and Approved for Design (AFD). AFD report shall be submitted within 1 (one) week after IFR report has been discussed/commented by both CONTRACTOR and COMPANY. The report shall contain the followings, as minimum:

• Executive Summary

• Introduction (to show the background of review, objective and scope of facilities)

• Methodology

• Results

• Overall Recommendation/Conclusion

Final reports are to be issued as follows:

• Two hard printed copy

• One soft electronic in its native file format for report including native software file

• One Adobe colored PDF file converted (NOT SCANNED) from the native file

Service Completion 5.2

The services shall be conducted and completed on a lump sum basis.

Satisfactory completion of services shall be subject to CONTRACTOR acceptance. No acceptance shall occur until the end of the Services and other completed deliverables have been delivered and accepted by the CONTRACTOR and COMPANY.

Contractor would sign the invoice from the THIRD PARTY in consultation with COMPANY to acknowledge the acceptance of the services.



6. ATTACHMENTS

Term of Reference (ToR) for FERA

Term of Reference (ToR) for QRA


TERM OF REFERENCE (TOR) FOR FERA




Document No. : Part of TBD-TJ-G10-LC-RQ-9002


Approval



AAnugrahesa

Stamp


Term Of Reference For FERA_Rev. B1 Page 2 of 19

RECORD OF REVISION

Rev. No.





TABLE OF CONTENT


TABLE OF CONTENT ................................................................................................................ 3

1. INTRODUCTION ................................................................................................................. 5


Objectives ................................................................................................................... 6 1.2

Scope .......................................................................................................................... 6 1.3

References.................................................................................................................. 6 1.4

Abbreviation ................................................................................................................ 8 1.5


2. FACILITY DESCRIPTION .................................................................................................... 9

3. METHODOLOGY .............................................................................................................. 10

Introduction ............................................................................................................... 10 3.1

Steps ......................................................................................................................... 10 3.2

Basis and Assumptions ............................................................................................. 14 3.3

Reporting .................................................................................................................. 18 3.4



LIST OF TABLES

Table 1-1 List Specification and Documentation ......................................................................... 6

Table 3-1 Ambient Air and Seawater Data ............................................................................... 14

Table 3-2 List of Fire Impact Criteria ........................................................................................ 17

Table 3-3 Explosion Overpressure Criteria ............................................................................... 18

LIST OF FIGURES


Figure 2 Release Rate Calculation ........................................................................................... 12



1. INTRODUCTION


SAKA Indonesia Pangkah Limited / SIPL (herein referred as COMPANY) has been commissioned to undertake the operator of Ujung Pangkah Block in East Java since January 2014 from HESS. The Ujung Pangkah field is located offshore of the north coast of East Java approximately 35 km north of Gresik, East Java, Indonesia; lies adjacent to the Bengawan Solo river delta.



The production facility at Tambakboyo Field will consist of one (1) unmanned Wellhead Platform (WHP-E) with minimum facilities installed. WHP-E will be connected by subsea pipelines and cables to existing offshore platform (WHP-B, CPP and AUP).

The WHP-E Tambakboyo platform is designed to accommodate the concept of gradual development (phasing) with the first phase is installation of 3 wellheads and the next phase, another 4 wellheads. WHP-E will be designed to accommodate activities such as well intervention and well maintenance using the rig less method, namely with Hydraulic Work Over Units (HWU).

The production results from the Tambakboyo Field well will be sent to the production facility in

the WHP-B platform for further processing at the CPP platform and commingled with the

production from other wells at Ujung Pangkah Fields to the Onshore Processing Facility (OPF)

via 18” export pipeline (40 km length).









Objectives 1.2

This Term of Reference (TOR) will produce rule set to be used for FERA Study. The objectives

of the FERA Review are:

Identify potential hydrocarbon fire events;

Identify the consequences of credible scenarios;

Identify credible hydrocarbon release case potentially resulting in jet fire, pool fire, explosion and other consequences;

Conduct quantitative assessment of fire consequences and the escalation potential from the major equipment from the facility;

Propose recommendations, as needed, to prevent, control, or mitigate potential hazards;

Provide assistance to facility management in their efforts to manage risks.

Scope 1.3

The scope of the Fire and Explosion Risk Assessment (FERA) is to access and identify the credible potential fire events and evaluate of fire consequences and the escalation potential from the major equipment for all facilities at WHP-E platforms, which connected to WHP-B platform through Subsea pipeline, as well as the modification of existing WHP-B platform during this Tambakboyo Field Development FEED phase. The remaining WHP-B platform facilities outside of modification scope were excluded from the scope of the study. Reservoirs and wellheads on WHP-E also excluded from the study as they are normally under drilling management.

References 1.4


Table 1-1 List Specification and Documentation


TBD-TJ-W8-PI-LY-3001 MAIN DECK EQUIPMENT LAYOUT EL +21605

TBD-TJ-W8-PI-LY-3002 CELLAR DECK EQUIPMENT LAYOUT EL +13500

TBD-TJ-W8-PI-LY-3003 SUB-CELLAR DECK EQUIPMENT LAYOUT EL +9500

TBD-TJ-W8-PI-LY-3004 JACKET WALKWAY EQUIPMENT LAYOUT EL +4286




TBD-TJ-W8-PI-LY-3005 WHP-E EQUIPMENT LAYOUT - MAIN DECK (PHASE-2)

TBD-TJ-W8-PI-LY-3006 WHP-E EQUIPMENT LAYOUT - CELLAR DECK (PHASE-2)

TBD-TJ-W8-PI-LY-3007 WELLHEAD ACCESS PLATFORM EQUIPMENT LAYOUT EL +18205

TBD-TJ-G10-PG-BD-0001 PROJECT DESIGN BASIS

TBD-TJ-G10-LC-PH-9001 SAFETY DESIGN PHILOSOPHY

TBD-TJ-W8-PR-FD-1001 PFD FLOWLINE & EXPORT

TBD-TJ-W8-PR-FD-1002 UFD WATER & DIESEL

TBD-TJ-W8-PR-FD-1003 UFD DRAIN & VENT SYSTEM

TBD-TJ-W2-PR-FD-1201 PFD WHP-B FLOWLINES & SEPARATOR (MODIFICATION)

TBD-TJ-W2-PR-FD-1202 PFD WHP-B GAS/LIQUID IMPORT AND EXPORT (MODIFICATION)

TBD-TJ-W8-PR-DR-1001-01 P&ID WELLHEAD & FLOWLINE - WELL 1



TBD-TJ-W8-PR-DR-1001-04 P&ID WELLHEAD & FLOWLINE - WELL 4 (PHASE-2)




TBD-TJ-W8-PR-DR-1002 P&ID WELLHEAD CONTROL PANEL

TBD-TJ-W8-PR-DR-1003 P&ID TEST HEADER & MPFM

TBD-TJ-W8-PR-DR-1004 P&ID PRODUCTION HEADER

TBD-TJ-W8-PR-DR-1005 P&ID EXPORT PIPELINE

TBD-TJ-W8-PR-DR-1006 P&ID VENT & CLOSED DRAIN HEADER

TBD-TJ-W8-PR-DR-1007 P&ID CLOSED DRAIN VESSEL AND PUMP

TBD-TJ-W8-PR-DR-1008 P&ID OPEN DRAIN SYSTEM

TBD-TJ-W8-PR-DR-1011 P&ID DIESEL AND WATER STORAGE SYSTEM

TBD-TJ-W2-PR-DR-1001 P&ID WHP-B IMPORT PIPELINE

TBD-TJ-W2-PR-DR-1424-MOD P&ID WHP-B EXPORT MANIFOLD (MODIFICATION)

ISO 17776 – 1ST

EDITION, 2000 PETROLEUM AND NATURAL GAS INDUSTRIES – OFFSHORE PRODUCTION INSTALLATIONS – GUIDELINES ON TOOLS AND TECHNIQUES FOR HAZARD IDENTIFICATION AND RISK ASSESSMENT



Abbreviation 1.5


AUP : Accommodation and Utilities Platform

CPP : Compression and Processing Platform


IEL : Intermediate Event Likelihood

L : Likelihood

MAE : Major Accident Events

NUI : Normally Unmanned Installation

OPF : Onshore Processing Facilities

P&ID : Piping & Instrumentation Diagram


SCE : Safety Critical Element

SIS : Safety Instrument System

TOR : Term of Reference


WHP : Well Head Platform









2. FACILITY DESCRIPTION

The wellhead platform (WHP-E) is designed with minimum facility to support the production. The wellhead platform has one production manifold and one test manifold. Test manifold is equipped with multiphase flowmeter as testing facility.

The fluids produced from Tambakboyo field will be sent to production facility at WHP-B platform prior processing at CPP platform and then commingled with production from other Ujung Pangkah fields to be processed at Onshore Processing Facility (OPF) via18” export pipeline (40 km length).

The subsea cable (power supply and fibre optic) connects WHP-E with Accommodation & Utility Platform (AUP). Subsea cable will penetrate and stop on WHP-B Platform, then continue routing to AUP via cable tray.

At WHP-B, the production fluids from WHP-E will be sent to CPP platform via existing platform bridge. The Tambakboyo fluids will be sent together with production from other Ujung Pangkah fields to existing three-phase MP Separator located at Central Processing Platorm (CPP). Gas from separator will be sent to gas scrubber at compressor package. The oil is routed to MP Oil Pump, while the water will be routed to Produced Water Treatment prior injection to wells.

Process facilities on the Wellhead Platform E will be limited to following systems :

- Wellhead and WHCP,

- Well flowlines and manifold,

- Well test manifold and metering,

- Production subsea pipeline,

- Closed drain system,

- Vent system,

- Open drain system,

- Diesel oil systems,

- Utility water systems.



3. METHODOLOGY

Introduction 3.1

The FERA methodology consists of the following main steps:

1. Identification of credible Major Accident Events (MAE) in terms of fire associated with the

normal operations phase of the facility;

2. Identification of the isolatable sections of the Tambakboyo Field Development, including

determination of physical properties and volumes of each of these Isolatable inventories;

3. Determine of the potential hazardous release scenarios, release type, event outcomes

(e.g. pool, jet fires and explosion) for each identified MAE;

4. Conduct of consequence modelling to determine the extent or magnitude of potential

hazardous outcomes;

5. Calculation of the discharge rate for a number of leak sizes for each release point;

6. Calculation of the effects of the fire scenarios. The effects are described in terms of

distances to damage thresholds generated by the reference release cases;

7. Frequency assessment and Event Tree Analysis;

8. Determination of consequences associated with each event;

9. Assessment of the hydrocarbon hazard impact to the asset, based on the defined

impairment criteria;

10. Summarize conclusion and provide recommendation.

The Fire and Explosion Risk Assessment is a consequence-based study, i.e. no evaluation of the occurrence frequency of the assessed fire scenarios shall be included in the FERA report.

Steps 3.2

The steps required in FERA review is outlined below:

1. Isolatable Section Identification

The process systems within WHP-E are split into Isolatable sections, where in the event

of failure (i.e. leak), the process can be isolated by shutdown valves to minimize the

release inventory. For the purpose of this analysis, the hydrocarbon inventories in the

sections have been treated as either vapor phase (g), or liquid phase (l) inventories.

2. Fire Hazard Identification

The identification of the flammable materials handled in the process streams, and the

relevant fire scenarios which can develop in case of a loss of containment event, shall

be carried out with the process description, PFDs, heat and material balance, etc.

The plant system – including all vessels, piping and equipment that handle flammable

process fluids will be divided into isolatable sections considering isolation provisions. As

a result, a comprehensive list of potential loss of containment sources will be generated

for the subsequent consequence analysis.

Depending on the release conditions, the fire hazards from the hazardous inventories

expected in project facilities are as follows:



Flammable gas inventory

Flammable liquid inventory

3. Consequence Modelling

Consequence modelling is used to predict the size, shape, and orientation of hazard

zones resulting from releases of hazardous material. For each loss of containment

event, the consequence will be evaluated using the software PHAST by DNV-GL.

It will involve the following tasks:

Source Term / Discharge Modelling

Source term or discharge modelling involves determination of the maximum

discharge rate, release duration and other physical properties of the released

material, such as temperature and pressure. These estimated parameters are

then set as the initial conditions for the subsequent dispersion or fire effects

modelling.

For each release point, several leak sizes shall be evaluated, to provide a range of

credible release scenarios, from minor to major.

o Release Rate Calculation

In general the phenomena of discharge is characterized by transient

conditions, as the parameters that govern the discharge dynamics (internal

pressure, temperature, and inventory) are changing in time. The transient

character of the release is more evident in gas releases, due to the compressible

nature of the fluid, whilst in the event of releases from a liquid system, the internal

conditions tend to remain substantially unchanged until the inventory is depleted.

Nevertheless, depending on the leak size, the inventory and the normal flow rate

through the section, also some gas releases may be treated as approximately

steady. For releases downstream pumps, the outflow rate is capped to 130% of the

pumped flowrate.

To the aim of the assessment to be performed in the FERA, the discharge

rate of interest shall be evaluated at different times, depending on the

damage criteria considered. In particular, with reference with the targets and

criteria defined in AS 8, the release rates shall be evaluated at the following

conditions:

- Peak release rate (at the start of the release)

- At 5 minutes

- At 10 minutes

- At 30 minutes

The determination of the discharge rate at different times will take into account the

depressurization of the section, and the ESD considered complete after 10 minutes

from the start of the release. As an example, the procedure followed to determine

the release rate at 10 minutes is illustrated in the flow-chart of Figure 2.



Figure 2 Release Rate Calculation

Dispersion Modelling

This involves mathematical simulation of how the released materials disperse in

the ambient atmosphere. Downwind and crosswind concentrations are determined to

find the gas cloud hazard envelope.

Vapor / two-phase dispersion modelling will be conducted using PHAST’s Unified

Dispersion Model (UDM). The model considers the following aspects of vapor cloud

behavior in dispersion modelling:

o Continuous, instantaneous, and time-varying releases

o Jet, heavy-gas and passive dispersion

o Elevated, touchdown and ground level dispersion

o Droplet dispersion, vaporization, and rain-out (only for pure substances, or

mixtures modelled as a pseudo-component)

o Dispersion over land or water surfaces

It is recalled that the effect of obstacles / sloping surfaces etc. cannot be captured in

PHAST, which is not a CFD program.

Fire Modelling

Physical effects modelling will be used to determine the magnitude of damage caused

by exposure to fire and heat radiation. The following possible hazardous outcomes will

be considered in the FERA.

o Jet Fire

Jet fires result from immediate ignition of a pressurized release (above 2 bara) of

flammable gas or liquid. The pressure behind the release produces a high



velocity jet of gas and/ or liquid which entrains air to form a flammable mixture.

Ignition of this mixture produces a jet fire. In case of two-phase release, only the

release fraction that does not rain-out will feed the jet-fire.

o Pool Fire

A pool fire results from ignition of the vapour over a flammable liquid pool. The

Early Pool-fire model shall be used to estimate the size of the pool, where

the spreading of the pool is limited by the equilibrium between feed rate

and burning rate. In any case, if a bund is provided as a mitigation

measure, the pool fire dimensions shall not exceed the size of the bund area,

which can be modelled either as an equivalent circular area (software PHAST).

o Flash Fire

Following a release, if there is no immediate ignition, the vapour will disperse in

the atmosphere and gradually dilute. Some portion of this vapour cloud will have

a concentration between the upper flammability (UFL) limit and lower

flammability limit (LFL). If this flammable portion of the cloud subsequently

comes in contact with an ignition source, the vapour cloud may ignite and burn

rapidly with a sudden flash. This is termed a flash fire and is distinct from a

vapour cloud explosion in that flame speeds are lower and no significant

overpressure is generated. Due to the extreme short duration of a flash fire, no

damage effect on equipment is expected.

In the FERA context, flash fires will be assessed for the potential effects on

escape ways and muster areas; radiation effects outside the flame are

assumed to be negligible, and damage to people is limited to the flammable

envelope where the flame propagates.

4. Impact Assessment

The main purpose of the FERA is to identify equipment / structures that in case of

fire, may be impaired to the point of losing their containment / support properties or

safety function, thus needing some kind of fire protection.

In particular, the following radiation contours shall be generated, in order to enable

the identification of the items involved, and check whether they are adequately

protected by PFP:

200 kW/m2 and 100 kW/m2 (for certain periods depend on fire scenario and type

of structure): the requirements for the application of Passive Fire Protection to

structures and equipment shall be established following a risk based approach.



Basis and Assumptions 3.3

The assumptions taken for FERA are:

1. Ambient Conditions

Table 3-1 Ambient Air and Seawater Data

The result relevant to all conditions shall be calculated, and the most conservative result

shall be considered for design purposes.

2. Reference Case for Process Data

Normal operating conditions shall be considered for consequence assessment.

Actual compositions indicated in HMB shall be used for input to consequence software,

allowing for the necessary adjustments required by the optimal use / limitations of the

software PHAST for specific purposes (e.g. maximum number of components, pseudo-

component vs multi-component thermodynamics, three phase systems, emissive power

calculation of flammable mixtures, etc.)

It is highlighted that the pseudo-component model does not allow to defined two-phase

conditions as internal conditions for the release. Piping where internal conditions

correspond to two-phase flow shall be generally modelled as all-vapor systems, which

usually still provides a reasonable estimate of the release rate.



3. Plant Sectionalization

The potentially hazardous systems shall be divided into sections depending on process

conditions such as temperature, pressure, phase etc. and the provision of isolation

elements.

The grouping of process sections and selection of scenarios shall be based on

PFDs/P&IDs, and HMB.

The sectioning exercise will consider the following:

Identification and location of isolation elements: Emergency isolation valves shall

generally be considered for segregating process sections. Other forms of

positive isolation will be reviewed on a case by case basis. In general, blind

flanges, closed spectacle blinds, closed double block and bleed valves or

normally closed valves may be treated as isolations points, while check valves,

process control valves, pumps and compressors usually are not.

Stream Phases: Phase boundaries shall be considered to split two-phase

isolatable sections, in order to assess both gas and liquid releases.

The following systems shall be considered can be seen in Table 2.1.

4. Inventory Estimation

The inventory of the isolated sections is calculated based on the mechanical datasheets

of the equipment, and the diameter and length of the piping.

In case of equipment partially filled with liquids, the liquid fraction shall be evaluated at

the High Alarm Level.

For consistency with the calculations performed by Process, calculated inventory will

include conservatively an additional 20% margin, to allow for uncertainties in pipe

routing, bends, etc.

Gas inventory input in PHAST in case of gas/liquid isolatable section will include also

the fraction of liquid flashed to the atmosphere, to approximately consider the

simultaneous outflow of the vapor and its replacement from the liquid vaporization.

The inventory estimation is used to determine which release rate may be sustained for

the periods considered for the release rate evaluation, i.e. 5 min, 10 min, and 30 min.

The determination of the total inventory released is not of primary interest in the FERA,

however this can be estimated as the sum of the isolated inventory plus a fraction of the

inflow into the section until isolation is achieved: Section inventory + Tisol x MIN [feed

rate, release rate], where Tisol is in all cases 10 minutes.

5. Modelled Leak Sizes

The following hole sizes will be considered in the FERA study:

10 mm

25 mm

50 mm

150 mm



The assessment for active fire protection will be based on the consequence results from

10 mm leaks. The requirements for passive fire protection will be based of the frequency

of exceeding the critical thermal loads defined in item no. 8 (thus the relative

contribution of all the leaks shall be accounted for)

The assessment of the escape routes / muster areas shall be based on the results from

50 mm leaks.

6. Time Required for Detection, Isolation and Blowdown

The following shall be considered in determining the release durations:

Automatic isolation / blowdown is assumed to be achieved within 2 minutes via

the ESD system

Manual isolation / blowdown is assumed to occur after 10 minutes if a

comprehensive fixed detection system is in place

Manual isolation / blowdown is assumed to occur after 15 minutes if no

comprehensive fixed detection system is in place.

7. Parameters for Consequence Modelling

PHAST software by DNV-GL will be used for conducting the consequence modelling for

FERA. The following provides a summary of the key parameters that will be considered

in the consequence modelling.

Release elevation: 1 m above grade shall be considered by default, however minimum

actual release height shall be considered for sections at elevation.

Release direction: Jet Fire / Flash Fire – horizontal non-impinging

Pool Fire / Flash Fire – downward impinging

Surface Roughness: 0.1 m

Averaging time for dispersion modelling: Flammable releases – 18.75s (PHAST default)

Consequence Models:

Jet Fire – Cone Model (DNV recommended)

Pool Fire – No bund: Equilibrium pool diameter (early pool fire)

Bund: Pool fire dimensions limited to the bund area

Solar Radiation Flux: Not included in fire radiation calculations

Height for reporting results: 1 m shall be considered by default, however different

heights may be also evaluated when necessary (e.g. detailed assessment for specific

equipment).

8. Fire Impact Criteria for Structure and Equipment

Fire scenarios may impair, at different heat flux and duration, several plant assets, including structures, equipment, buildings, and escape/muster facilities. The impact criteria considered in the FERA are presented in table below.



Table 3-2 List of Fire Impact Criteria

TYPE OF

SCENARIO THRESHOLD MINIMUM DURATION

REFERENCE HOLE

SIZE FOR DESIGN

PURPOSES

DESIGN REQUIREMENT

Jet Fire 200 kW/m2

5 min for lightweight

structure

10 min for heavyweight

structure

N/A

The requirements for the

application of Passive Fire

Protection to structures and

equipment shall be

established following a risk

based approach.

Jet Fire and

Pool Fire

100 kW/m2 30 min N/A

The requirements for the

application of Passive Fire

Protection to structures and

equipment shall be

established following a risk

based approach

12.5 kW/m2 10 min 10 mm

Impacted items shall be

provided with active fire

protection

6.3 kW/m2 N/A 50 mm Impairment criteria for escape

routes

4.7 kW/m2 N/A 10 mm

Impairment criteria for fire

actuation panel and deluge

valves

3.2 kW/m2 N/A 50 mm Impairment criteria for muster

areas

Flash Fire 90% LEL N/A 50 mm Impairment criteria for escape

routes and muster areas

The output maps relevant to the above mentioned thresholds shall be provided in the

FERA.

Although the actual shape of the impacted areas depends on the type of scenario (jet-

fire, pool-fire, flammable plume) and directional effects (jet direction, wind direction), the

contours reported in the FERA shall represent the distances to radiation uniformly drawn

from the center, or the outline, of the relevant equipment.

The contours shall be grouped as envelope of several scenarios, where appropriate.



9. Explosion Overpressure Criteria

The following explosion overpressure criteria will be reported for the explosion events in

FERA study is shown in Table 3.2.

Table 3-3 Explosion Overpressure Criteria

Explosion Overpressure (bar)

Impact Criteria / Consequence

Human Asset

0.07 Will cause injuries from flying debris (25% fatality)

Limited minor structural damage;

Partial demolition of houses

0.14 50% fatality Partial collapse of wall and roofs of houses

0.28 90% fatality Cladding of light industrial building ruptured

0.35 100% fatality Wooden utility poles snapped

Reporting 3.4

The FERA report should form the basis of the FERA team understanding the completeness of the study and the confidence that can be put in the result. It is an important document and should describe the objective and results of the FERA.

The report should consist the following as minimum:

1. Executive Summary

2. Project background

3. Project Scope and Objective

4. Reference documents

5. Description of Process

6. Methodology including nodes, guideword list

7. Frequency Assessment result

8. Release Rate Assessment Results

9. Consequence Assessment Results

10. Impact Assessment Results

11. FERA Conclusion and Recommendations

12. Document reference list

13. Appendices:

a. Terms of Reference

b. Assumptions Register

c. Isolatable Section Mark-Up

d. Heat and Mas Material Balance



e. Consequences Modelling Result

f. Dispersion, Jet Fire, Explosion and Pool Fire Contour

g. Parts Count Sheet

h. Event Tree Calculation

i. Phast Output

j. Impairment Frequency

Any recommendation arisen from the FERA will be delivered to the relevant discipline who complete and ensure the implementation of the recommendation in the relevant project document and procedure.


TERM OF REFERENCE (TOR) FOR QRA




Document No. : Part of TBD-TJ-G10-LC-RQ-9002


Approval



AAnugrahesa

Stamp


Term Of Reference For QRA_Rev. B1 Page 2 of 17

RECORD OF REVISION

Rev. No.



B 3.4 17

Subsea & Umbilical Cable (Electrical Power & FO) ...

Drop Object

Y Updated. The wording has been added accordingly.



TABLE OF CONTENT


TABLE OF CONTENT ................................................................................................................ 3

1. INTRODUCTION ................................................................................................................. 5


Objectives ................................................................................................................... 6 1.2

Scope .......................................................................................................................... 6 1.3

References.................................................................................................................. 7 1.4

Abbreviation ................................................................................................................ 8 1.5


2. FACILITY DESCRIPTION .................................................................................................. 10

3. METHODOLOGY .............................................................................................................. 11

Introduction ............................................................................................................... 11 3.1

Steps ......................................................................................................................... 11 3.2

Basis and Assumptions ............................................................................................. 15 3.3

Reporting .................................................................................................................. 17 3.4



LIST OF TABLES

Table 1-1 List Specification and Documentation ......................................................................... 7

Table 3-1 Ambient Air and Seawater Data ............................................................................... 15

Table 3-2 Risk Acceptance Criteria ..................................................................................... 16

LIST OF FIGURES


Figure 2 QRA Methodology ...................................................................................................... 11

Figure 3 ALARP Principle ........................................................................................................ 16



1. INTRODUCTION


SAKA Indonesia Pangkah Limited / SIPL (herein referred as COMPANY) has been commissioned to undertake the operator of Ujung Pangkah Block in East Java since January 2014 from HESS. The Ujung Pangkah field is located offshore of the north coast of East Java approximately 35 km north of Gresik, East Java, Indonesia; lies adjacent to the Bengawan Solo river delta.



The production facility at Tambakboyo Field will consist of one (1) unmanned Wellhead Platform (WHP-E) with minimum facilities installed. WHP-E will be connected by subsea pipelines and cables to existing offshore platform (WHP-B, CPP and AUP).

The WHP-E Tambakboyo platform is designed to accommodate the concept of gradual development (phasing) with the first phase is installation of 3 wellheads and the next phase, another 4 wellheads. WHP-E will be designed to accommodate activities such as well intervention and well maintenance using the rig less method, namely with Hydraulic Work Over Units (HWU).

The production results from the Tambakboyo Field well will be sent to the production facility in

the WHP-B platform for further processing at the CPP platform and commingled with the

production from other wells at Ujung Pangkah Fields to the Onshore Processing Facility (OPF)

via 18” export pipeline (40 km length).









Objectives 1.2

This Term of Reference (TOR) will produce rule set to be used for QRA Study. The objectives of

the QRA Review are:

Quantify the risk of all personnel from accident events associated with working at the facility;

Identify Major Accident Event (MAE) that could impair WHP-E and/or cause fatality to its personnel during site visit to the platform;

Quantify the process risk which uses frequencies and consequences from FERA study. Furthermore, toxic risk, occupational and transportation risks will also be assessed;

Calculate/quantify the Individual Risk per Annum (IRPA) of WHP-E personnel and Potential Loss of Life (PLL) due to process hydrocarbon hazards and non-hydrocarbon hazards associated with WHP-E platform;

Evaluate the acceptability of these risk levels against the stipulated Risk Acceptance Criteria;

Propose recommendations, if applicable, practical and effective measures to further reduce the risks in line with the As Low As Reasonably Practicable (ALARP) principle;

Provide assistance to facility management in their efforts to manage risks.

Scope 1.3

The scope of Quantitative Risk Assessment (QRA) is to access the risks to personnel due to potential Major Accident Events (MAEs) during normal operation on WHP-E platform including the subsea pipeline connection from WHP-E to existing WHP-B. The risk calculated is the incremental risk to the operator during his time. This is only a fraction of the total working time and the operator will be exposed to different risk level from each of the fatalities visited. The incremental risk calculated for WHP-E platform and pipeline need to be added to the risk level of all assets to determine the overall risk.

The scopes of this QRA are as follows:

Estimation of the event frequency and consequence impact arising from MAEs on WHP-E platform;

Estimation of IRPA and PLL from:

Hydrocarbon hazards (topside and blowout); and

Non-hydrocarbon hazards (ship collisions, structural failures, boat transport risk, dropped objects, occupational hazards and non-process fire).



Generate and Evaluate the LSIR, IRPA and PLL values for personnel working on WHP-E; and

Evaluation of the quantified risk levels against the stipulated Risk Acceptance Criteria to ensure that the risks to personnel are within acceptable levels.

References 1.4


Table 1-1 List Specification and Documentation


TBD-TJ-W8-PI-LY-3001 MAIN DECK EQUIPMENT LAYOUT EL +21605

TBD-TJ-W8-PI-LY-3002 CELLAR DECK EQUIPMENT LAYOUT EL +13500

TBD-TJ-W8-PI-LY-3003 SUB-CELLAR DECK EQUIPMENT LAYOUT EL +9500

TBD-TJ-W8-PI-LY-3004 JACKET WALKWAY EQUIPMENT LAYOUT EL +4286

TBD-TJ-W8-PI-LY-3005 WHP-E EQUIPMENT LAYOUT - MAIN DECK (PHASE-2)

TBD-TJ-W8-PI-LY-3006 WHP-E EQUIPMENT LAYOUT - CELLAR DECK (PHASE-2)

TBD-TJ-W8-PI-LY-3007 WELLHEAD ACCESS PLATFORM EQUIPMENT LAYOUT EL +18205

TBD-TJ-G10-PG-BD-0001 PROJECT DESIGN BASIS

TBD-TJ-G10-LC-PH-9001 SAFETY DESIGN PHILOSOPHY

TBD-TJ-W8-PR-FD-1001 PFD FLOWLINE & EXPORT

TBD-TJ-W8-PR-FD-1002 UFD WATER & DIESEL

TBD-TJ-W8-PR-FD-1003 UFD DRAIN & VENT SYSTEM

TBD-TJ-W2-PR-FD-1201 PFD WHP-B FLOWLINES & SEPARATOR (MODIFICATION)

TBD-TJ-W2-PR-FD-1202 PFD WHP-B GAS/LIQUID IMPORT AND EXPORT (MODIFICATION)








TBD-TJ-W8-PR-DR-1002 P&ID WELLHEAD CONTROL PANEL

TBD-TJ-W8-PR-DR-1003 P&ID TEST HEADER & MPFM




TBD-TJ-W8-PR-DR-1004 P&ID PRODUCTION HEADER

TBD-TJ-W8-PR-DR-1005 P&ID EXPORT PIPELINE

TBD-TJ-W8-PR-DR-1006 P&ID VENT & CLOSED DRAIN HEADER

TBD-TJ-W8-PR-DR-1007 P&ID CLOSED DRAIN VESSEL AND PUMP

TBD-TJ-W8-PR-DR-1008 P&ID OPEN DRAIN SYSTEM

TBD-TJ-W8-PR-DR-1011 P&ID DIESEL AND WATER STORAGE SYSTEM

TBD-TJ-W2-PR-DR-1001 P&ID WHP-B IMPORT PIPELINE

TBD-TJ-W2-PR-DR-1424-MOD P&ID WHP-B EXPORT MANIFOLD (MODIFICATION)

TBD-TJ-G10-LC-RP-9008 FIRE AND EXPLOSION RISK ASSESSMENT REPORT

TBD-TJ-G10-LC-RP-9003 HAZID STUDY REPORT

Abbreviation 1.5


ALARP : As Low As Reasonably Practicable

AUP : Accommodation and Utilities Platform

CPP : Compression and Processing Platform

ETA : Event Tree Analysis

FAR : Fatal Accident Rate

FEED : Front End Engineering Design


HAZID : Hazard Identification

IR : Individual Risk

IRPA : Individual Risk Per Annum

LSIR : Location Specific Individual Risk

MAE : Major Accident Events

NHHA : Non Hydrocarbon Hazard Analysis

NUI : Normally Unmanned Installation

OPF : Onshore Processing Facilities

P&ID : Piping & Instrumentation Diagram


PLL : Potential Loss of Life

QRA : Quantitative Risk Assessment

RADD : Risk Assessment Data Directory

TOR : Term of Reference




VCE : Vapor Cloud Explosion

WHP : Well Head Platform









2. FACILITY DESCRIPTION

The wellhead platform (WHP-E) is designed with minimum facility to support the production. The wellhead platform has one production manifold and one test manifold. Test manifold is equipped with multiphase flowmeter as testing facility.

The fluids produced from Tambakboyo field will be sent to production facility at WHP-B platform prior processing at CPP platform and then commingled with production from other Ujung Pangkah fields to be processed at Onshore Processing Facility (OPF) via18” export pipeline (40 km length).

The subsea cable (power supply and fibre optic) connects WHP-E with Accommodation & Utility Platform (AUP). Subsea cable will penetrate and stop on WHP-B Platform, then continue routing to AUP via cable tray.

At WHP-B, the production fluids from WHP-E will be sent to CPP platform via existing platform bridge. The Tambakboyo fluids will be sent together with production from other Ujung Pangkah fields to existing three-phase MP Separator located at Central Processing Platorm (CPP). Gas from separator will be sent to gas scrubber at compressor package. The oil is routed to MP Oil Pump, while the water will be routed to Produced Water Treatment prior injection to wells.

Process facilities on the Wellhead Platform E will be limited to following systems :

- Wellhead and WHCP,

- Well flowlines and manifold,

- Well test manifold and metering,

- Production subsea pipeline,

- Closed drain system,

- Vent system,

- Open drain system,

- Diesel oil systems,

- Utility water systems.



3. METHODOLOGY

Introduction 3.1

Quantitative Risk Assessment (QRA) is a systematic method of developing a numerical

estimate of the expected frequency and consequence of potential accidents associated with

normal operations within the platform area, based on engineering evaluation and mathematical

techniques. The logic flow diagram below outlines the general order taken through the QRA

model.

Figure 2 QRA Methodology

Steps 3.2

The steps required in QRA review is outlined below:

1. Data Gathering

The initial activity was to gather all data so that the analysis can be conducted on as

accurate information as possible. Data complied consisted of drawings and relevant

documentation (operating conditions, personnel distribution, etc) related to design of the

WHP-E installation. This included gathering information from the safety studies for

WHP-E installation (FERA report and HAZID study report).



2. Hazard Identification

The MAE scenario selection involves identifying physical situations (failure modes or

initiating events) that could lead to hazardous outcomes with the potential for fatality.

The MAE identification has been performed to evaluate the possible hazardous events

that might lead to loss of life, environment impact and asset. The MAEs shall be

identified from HAZID study report.

MAE such as blowout is typically considered in QRA study. Hence, it is also calculated

in this study. Assessment of the dropped object hazards has not been carried further.

However, the impact of dropped or swinging objects has been included in the leak

frequencies of process hydrocarbons (i.e. dropped object onto process lines) and

personnel occupational hazards (i.e. dropped or swinging object onto personnel).

3. Frequency Analysis

Frequency analysis provides information about how often the hazardous event is likely

to happen.

Frequencies for hydrocarbon hazards and non-hydrocarbon hazards are calculated

using Event Tree Analysis (ETA). ETA involves taking each initiating event through a

defined sequence of conditional outcomes, determining the likelihood that an associated

outcome will occur. ETA takes into account the necessary conditions for the hazardous

outcome to occur – such as ignition – but also the presence of protective systems

identified as safety barriers, which are in place and may prevent the final outcome from

occurring (such as isolation which prevent escalation). By assigning probabilities to

each branch of the event tree, the final frequency of each outcome can be determined.

4. Consequence Modelling

Consequence modelling is used to predict the size, shape, and orientation of hazard

zones resulting from releases of hazardous material. For each loss of containment

event, the consequence will be evaluated using the software PHAST by DNV-GL.

It will involve the following tasks:

Source Term / Discharge Modelling

Source term or discharge modelling involves determination of the maximum

discharge rate, release duration and other physical properties of the released

material, such as temperature and pressure. These estimated parameters are

then set as the initial conditions for the subsequent dispersion or fire effects

modelling.

For each release point, several leak sizes shall be evaluated, to provide a range of

credible release scenarios, from minor to major.

o Release Rate Calculation

In general the phenomena of discharge is characterized by transient

conditions, as the parameters that govern the discharge dynamics (internal

pressure, temperature, and inventory) are changing in time. The transient

character of the release is more evident in gas releases, due to the compressible

nature of the fluid, whilst in the event of releases from a liquid system, the internal

conditions tend to remain substantially unchanged until the inventory is depleted.

Nevertheless, depending on the leak size, the inventory and the normal flow rate

through the section, also some gas releases may be treated as approximately



steady. For releases downstream pumps, the outflow rate is capped to 130% of the

pumped flowrate.

Dispersion Modelling

This involves mathematical simulation of how the released materials disperse in

the ambient atmosphere. Downwind and crosswind concentrations are determined to

find the gas cloud hazard envelope.

Vapor / two-phase dispersion modelling will be conducted using PHAST’s Unified

Dispersion Model (UDM). The model considers the following aspects of vapor cloud

behavior in dispersion modelling:

o Continuous, instantaneous, and time-varying releases

o Jet, heavy-gas and passive dispersion

o Elevated, touchdown and ground level dispersion

o Droplet dispersion, vaporization, and rain-out (only for pure substances, or

mixtures modelled as a pseudo-component)

o Dispersion over land or water surfaces

It is recalled that the effect of obstacles / sloping surfaces etc. cannot be captured in

PHAST, which is not a CFD program.

Fire Modelling

Physical effects modelling will be used to determine the magnitude of damage caused

by exposure to fire and heat radiation. The risk assessment has been carried out using

an integrated set of Excel spreadsheets.

5. Risk Measures

a. Location Specific Individual Risk (LSIR)

The Location Specific Individual Risk (LSIR) expresses the risk exposure to an

individual in a particular area. The risk exposure is calculated for all relevant

hazards and summed to give the overall risk in particular areas of the platform. In the

fatality estimation, the consequences of each outcome from an accidental event

are represented by the probability of death to an individual present in that area at the

onset of the event. The LSIR can be represented as:

LSIR = Outcome Frequency x Probability of death for an individual present all

time in area

LSIR is a useful measure for establishing the most hazardous areas of the platform but

does not consider the likelihood of an individual actually being present at the time of the

incident.

b. Individual Risk per Annum (IRPA)

Individual Risk Per Annum (IRPA) is to compare the risk levels between different worker

groups. IRPA is calculated based on individual basis where personnel with similar tasks

are grouped to the same worker category and spend the same amount of time in

particular location on the facility.

The overall IRPA for specific groups of workers from events on the facility is therefore

the sum over all areas of the Location Specific Individual Risk times the presence factor

in the area; i.e.

IRPA = ∑ LSIR x Presence Factor



where:

∑ = sum for all areas of the facility

The proportion of time in each location on the facility is estimated according to the

nature of the individual’s work.

IRPA is a useful measure because it is essentially independent of the number of people

exposed. In this analysis, IRPA has been applied to different worker groups.

c. Potential Loss of Life

Potential Loss of Life (PLL) is defined as the long term average number of fatalities per

year due to a specific cause and can be expressed mathematically as:

PLL = IRPA x N

where:

PLL = Potential Loss of Life

IRPA = Individual Risk Per Annum

N = number of personnel in each worker group

PLL measures the risk to a group of people as a whole and does not provide details on

whether a particular worker group is more exposed than others.

In measuring the effectiveness of various risk reducing measures, it is most appropriate

to compare the PLL values as this gives a measure of the true benefit taking into

account the potential number of persons affected.



Basis and Assumptions 3.3

The assumptions taken for QRA are:

1. Ambient Conditions

Table 3-1 Ambient Air and Seawater Data

The result relevant to all conditions shall be calculated, and the most conservative result

shall be considered for design purposes.

2. Reference Case for Process Data

Normal operating conditions shall be considered for consequence assessment.

Actual compositions indicated in HMB shall be used for input to consequence software,

allowing for the necessary adjustments required by the optimal use / limitations of the

software PHAST for specific purposes (e.g. maximum number of components, pseudo-

component vs multi-component thermodynamics, three phase systems, emissive power

calculation of flammable mixtures, etc.)

It is highlighted that the pseudo-component model does not allow to defined two-phase

conditions as internal conditions for the release. Piping where internal conditions

correspond to two-phase flow shall be generally modelled as all-vapor systems, which

usually still provides a reasonable estimate of the release rate.

3. Risk Acceptance Criteria

Once the risks have been estimated, they are “benchmarked” against acceptance criteria to see if they place personnel at an unacceptable level of risk. The criteria typically identify three bands. The impact criteria considered in the QRA are presented in table below.



Table 3-2 Risk Acceptance Criteria

RISK CRITERIA IRPA VALUE DESCRIPTION

Unacceptable > 1.00E-03

The risks are considered too high for an individual to bear and need to be reduced in order for the project to go ahead. Efforts must be made to reduce the risk to the level ALARP.

ALARP 1.00E-05 – 1.00E-03

The risks are considered as elevated with respect to the everyday risks faced by an individual but this increase in risk is considered acceptable when placed in the context of benefit to the person and the community as a whole from the project.

Should the risks fall into this band then it needs to be demonstrated that all the risks are understood, control measures are in place and that sufficient mitigation measures are in place consummate with the level of risk posed.

Acceptable < 1.005E-05

The lower level covers the background risk people could typically be exposed to during everyday life. Should the overall risk fall below this level then no additional mitigation measures are considered necessary as the risks are no greater than those faced and accepted by people conducting everyday life.

The framework for risk acceptance criteria defines an upper maximum tolerable and a lower minimum negligible risk level. The risks to personnel shall be As Low As is Reasonably Practicable (ALARP), or in the region of 1.00E-05 – 1.00E-03 as illustrated in Figure 3.

The ALARP demonstration shall be undertaken by means of a systematic process of review, identification, analysis, and evaluation of potential risk reduction measures (risk reduction measures must be applied until the cost of incorporating any additional risk reduction measures in disproportionate to the benefit obtained).

Figure 3 ALARP Principle



Reporting 3.4

The QRA report should form the basis of the QRA team understanding the completeness of the study and the confidence that can be put in the result. It is an important document and should describe the objective and results of the QRA.

The report should consist the following as minimum:

1. Executive Summary

2. Project background

3. Project Scope and Objective

4. Reference documents

5. Description of Process

6. Methodology including nodes, guideword list

7. Process Hydrocarbon Hazard Analysis

8. Non-Hydrocarbon Hazard Analysis

9. Overall Risk Results

10. QRA Conclusion and Recommendations

11. Document reference list

12. Appendices:

a. Terms of Reference

b. Assumptions Register

c. Topside Process Hydrocarbon Calculation

d. Blowout Risk Calculation

e. Ship Collision Risk Calculation

f. Structural Failure Risk Calculation

g. Boat Transport Risk Calculation

h. Occupational Hazard Risk Calculation

i. Non-Process Fire Risk Calculation

j. Subsea & Umbilical Cable (Electrical Power & FO) Risk Calculation

k. Dropped Object Risk Calculation

Any recommendation arisen from the QRA will be delivered to the relevant discipline who complete and ensure the implementation of the recommendation in the relevant project document and procedure.

B1