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Petroleum Development Oman L.L.C.

Emergency Response Document: Part III Contingency Plan

Volume 15: South Oman Gas Line (SOGL)

Document ID PR-1275

Document Type Procedure

Security Unrestricted

Discipline UIPT

Owner UIPT – Infrastructure Pipeline System & Terminal Manager

Issue Date 24 March 2014

Version 5.0

Keywords: This document is the property of Petroleum Development Oman, LLC. Neither the whole nor any part of this document may be disclosed to others or reproduced, stored in a retrieval system, or transmitted in any form by any means (electronic, mechanical, reprographic recording or otherwise) without prior written consent of the owner.

Emergency Procedure, SOGL Version 5.0

Authorised For Issue

Revision Record:Version No.

Date Custodian Scope / Remarks

Version 5.0 24/03/2014 UIPT/32

Updated Reference Indicators, telephone numbers. Material Specification and Capacity between Isolation Points, SOGL System and Schematic diagram.

Version 4.0 12/01/2009 UIP/31 Fourth Issue. UIP/31 update and revision

Version 3.0 12/09/2005 UIP/31 Third Issue. UIP/31 update and revision.

Version 2.0 11/05/2003 TTP/4 Second Issue. TTP/4 Technical Update

Version 1.0 02/11/1999 OIP/4 First Issue. CSM/4 comments included.

Reviewed By:

Terminology:In the documents of the PDO Emergency Response Management System the following words are used to express the level of requirement for actions described within the text:

Shall, Will : Means mandatory. Such actions must be followed

Should : Means strongly recommended

May : Means acceptable and to be considered

PR-1275 Page 2 March 2013


Contents

1 Introduction...............................................................................................................................................51.1 Objectives of the Emergency Response Management System........................................................5

1.2 Purpose of the Document.................................................................................................................5

1.3 Structure of this Document..............................................................................................................5

1.4 Document Ownership and Maintenance..........................................................................................6

1.5 Review and Update..........................................................................................................................6

2 Emergency Procedure..............................................................................................................................72.1 Strategy for SOGL Failures.............................................................................................................7

2.2 Local Emergency Base Controllers.................................................................................................7

2.3 Emergency Reporting......................................................................................................................7

2.4 Area Safeguarding and Access Control...........................................................................................7

2.4.1 Locating the Site of the Leak...............................................................................................7

2.4.2 Gas Testing & Area Isolation...............................................................................................8

2.4.3 Emergency Site Communications........................................................................................8

2.4.4 Leak Isolation.......................................................................................................................8

2.5 Assessment of Leaks........................................................................................................................8

2.6 Gas Leak Rate Data.........................................................................................................................9

2.7 LEBC & OSC Specific Checklist for Pipelines Emergencies.........................................................9

2.8 Stand Down of the Emergency Team............................................................................................10

3 South Oman Gas Line Technical Details..............................................................................................113.1 Asset Overview..............................................................................................................................11

3.1.1 SOGL Gas Suppliers..........................................................................................................11

3.1.2 SOGL Gas Consumers.......................................................................................................12

3.2 Pipeline Specifications...................................................................................................................16

3.2.1 Pipeline Classification........................................................................................................16

3.2.2 Pipeline Volume data.........................................................................................................17

3.2.3 Line Capacity between Isolation Points.............................................................................17

4 Emergency Repairs.................................................................................................................................194.1 System Preparation........................................................................................................................19

4.1.1 Line Isolation and Depressurisation...................................................................................19

4.1.2 Line Degassing...................................................................................................................19

4.1.3 Specialist Repair Resources:..............................................................................................19



4.1.4 SOGL Leak Repair Response.............................................................................................20

5 Business Resumption..............................................................................................................................215.1 Failure mechanisms.......................................................................................................................21

5.1.1 Failure of a Gas Supplier....................................................................................................21

5.1.2 Leak on the Gas Line..........................................................................................................21

5.1.3 Contamination of the Gas...................................................................................................22

5.1.4 Obstruction of the Gas Line...............................................................................................22

5.2 Impact of loss of gas......................................................................................................................22

5.3 Load Shedding for Southern region...............................................................................................24

5.4 Ensuring Business Continuity........................................................................................................25



Tables and Figures

Table 2.5 Leak Risk Assessment...........................................................................................................8

Table 2.6A LEL Hazardous Areas........................................................................................................9

Table 3.1.1C Gas Availability.............................................................................................................12

Table 3.1.2 Gas Consumers.................................................................................................................14

Figure 3.2 South and Central Oman Gas Line Suppliers and Consumer............................................15

Table 3.2.1 Pipeline Classification......................................................................................................17

Table 3.2.2 Pipeline Volume Data......................................................................................................17

Table 3.2.3 Line Capacity between Isolation Points...........................................................................18

Table 4.2.7 Specialist Repair Resources.............................................................................................19

Appendices

Appendix A: Glossary Of Terms, Definitions & Abbreviations.........................................................28

Appendix B: Telephone Contacts........................................................................................................30

Appendix C: List Of Approved Contractors For Pipeline Emergency Repair....................................33

Appendix D: Change Control Form....................................................................................................34



1 Introduction

1.1 Objectives of the Emergency Response Management SystemThe prime objective of PDO in emergencies is to ensure that activities are carried out with the following priorities:

Safeguard Lives People P

Protect the Environment Environment E

Protect Company or Third Party Assets Assets A

Maintain the Company Image/Reputation Reputation R

Personnel involved in dealing with emergency shall follow these priorities when making decisions and developing action plans.

1.2 Purpose of the DocumentThis document describes specific response and recovery arrangements for emergencies occurring on the PDO South Oman Gas Line Asset [SOGL] consisting of the SOGL pipework and ‘Pig’ launcher / receivers.

This plan considers scenarios affecting SOGL Operations between Saih Nihayda in the North and Harweel in the South which are controlled through Local Emergency Team Organisations. It is not site or geographically specific and is applicable to the full length of the SOGL between the stated points.

The initial response to emergencies involving the SOGL asset will be managed by area emergency control teams. This document details actions over and above generic emergency response activities which need to be considered by emergency response personnel when responding to an emergency on the SOGL.

Distribution/Target Audience

This document is available in Livelink. If you do not have access to Livelink contact UIPT/32 to obtain a copy. The following receive hard copies:

UIPT, UIPT/1, UIPT/3, UIPT/32 & UIPT/4 UIC & UIC/4 Local Emergency Control Centres (LECC’s) via UIC/4 Corporate Emergency Control Centre (CECC) via UIC/4

1.3 Structure of this DocumentThis document is designed to be used in conjunction with Part II Company Procedure PR-1065 which details the PDO emergency call out system and generic roles and responsibilities for Area Emergency Control teams. The manual is structured as follows:

Emergency procedure for SOGL SOGL Technical Details Emergency Repairs Business ResumptionThis manual does not include the detailed repair for pipelines. Reference should be made to:

Pipeline Emergency Repair Manual GU379 available in LIVELINK.

which is the responsibility of the pipeline focal point in engineering.



1.4 Document Ownership and MaintenanceDocument Owner

Document Owner is the Infrastructure Pipeline System & Terminal Manager [UIPT]. UIPT is responsible for:

Approval of the document following review and revision Annual confirmation to UIC by email that the plan is still ‘Fit for Purpose’ Ensuring the document defines an organisation and identifies resources to

enable PDO to adequately respond to identified scenarios Document Holder

Document Holder is the Terminal, MOL & SOGL Delivery Team Leader [UIPT/3]. UIPT/3 is responsible for:

The technical accuracy of the document Ensuring update, review and revision of the document not later than every 3 years and whenever

there are significant changes to the company organisation, resources or assets addressed in the document

Delegation of maintenance and implementation of the document is via a document Custodian.

Document Custodian

The Custodian of this document is Pipeline System Operation Support, UIPT/32. On behalf of the document holder, UIPT/32 is responsible for maintenance and implementation. This includes:

Ensuring updates are distributed. Implementing review and update. Planning and executing emergency response exercises.

Related FormsUsers who identify errors, inaccuracies or ambiguities in this document are requested to advise the custodian by returning the Change Control form (Appendix D) and a copy of the relevant page(s) with their comments.

1.5 Related Business Control DocumentsCode of Practice Emergency Response Document part I CP-123Procedure Emergency Response Document part II, Company

ProcedurePR-1065

Procedure Emergency Response Document part III, Contingency Plan, Vol. 3 Production Operations

PR-1066

Procedure Emergency Response Document part III, Contingency Plan, Vol. 4, Main Oil Line

PR-1067

Procedure Emergency Response Document part III, Contingency Plan, Vol. 14, Government Gas System

PR-1246

Procedure Emergency Response Document part III, Contingency Plan, Vol.5, Terminal & Tank Farm

PR-1068

Guideline Pipeline Repair Manual DEP 31.40.60.12

1.6 Review and UpdateThis document will be reviewed following major changes to the asset, PDO organisation or operations process. Notwithstanding the above, as a minimum it is required that it be reviewed not later than every three years.



2 Emergency Procedure

2.1 Strategy for SOGL FailuresThe strategy for a confirmed leak is to stop any supply to the leak location by closing the adjacent upstream and downstream block valves.

The public are to be prevented from approaching the area and all ignition sources must be eliminated. When site control is established, recovery, repair and clean-up can proceed according to the following steps:

Isolate leaking section Prepare area for safe working Mobilise emergency vent/flares Blowdown leaking pipelines section Purge with nitrogen Contact with power plant operator (UIE/3) to divert power away from affected power plant Repair leak Resume operation Clean up and restore

2.2 Local Emergency Base ControllersThe Local Emergency Base Controllers (designates and alternates) are expected to be conversant with this plan; for other team members, familiarity with the plan is recommended.

North Designate AlternateLEBC ONO/1Q, GGO/1Q ONO/4Q, GGO/4Q

South Designate AlternateLEBC OSO/1M, OSO/1N, OSO/1B OSO/4M, OSO/4N, OSO/4B

2.3 Emergency ReportingSOGL leaks will be reported by PDO or Contractor staff. A further source of leak reports is possible from non involved third parties, i.e. the local population. In this case, it is quite likely that the report, by the time it reaches the CCR, is both inaccurate and misleading.

2.4 Area Safeguarding and Access Control2.4.1 Locating the Site of the Leak

The search team will approach the area of the suspected leak using extreme caution and depending on:

Leak location obvious and ignition occurred; i.e when ignition has occurred, the search vehicle shall park a safe distance upwind or crosswind from the site of the leak or flame front and approach the leak area with care to try and ascertain the approximate dimension of the leak.

Leak location is obvious but ignition has not occurred; then the search team will park upwind or crosswind so that the search vehicle will not enter the gas release envelope. Personnel shall use breathing apparatus and using gas detectors try and establish the approximate edges of the gas cloud at ground level. If practical and but only if deemed safe to do so, an attempt may be made to ascertain the size of the hole in the pipeline.

Leak location not obvious; the search for the incident site will be undertaken using the following procedures as relevant:

Gas Testing Procedure PR-1154.

Entry into a Confined Space Procedure PR-1148

Hydrogen Sulphide Management Procedure PR-1078

Note: If in any doubt about the extent of any gas leak immediately stop vehicles and switch off the engines and proceed on foot donning breathing apparatus and gas detectors.

2.4.2 Gas Testing & Area Isolation



In the event of a gas leak, the surrounding area must be cordoned off AS SOON AS POSSIBLE by use of hazard warning tape, signs or whatever other means are available.

The affected area will be tested for the presence of toxic or explosive gas and the boundaries will be assessed for possible ignition sources. Gas testing, and atmospheric conditions will be monitored throughout the activity period and the hazard boundaries and restrictions modified accordingly. Wind direction and speed will be monitored and taken account of in the zone isolation. As a minimum, the surrounding area will be cordoned off in accordance with the Leak Rate Tables in 2.6

Following initial safeguarding activities, the area will be restricted to Emergency Response / Recovery Personnel and gas testing, wind speed and its direction will continue to be monitored throughout the emergency period, with the hazard boundaries and restrictions modified as necessary.

Enlist the ROP for controlling access to the site.

2.4.3 Emergency Site CommunicationsWith a SOGL leak it will generally take a long time to implement a complete repair, it is therefore advised at the earliest opportunity to mobilise a "Communications Container" and 4x4 communication vehicle as a forward command post. The communications containers are situated at Nimr, Bahja, Fahud and MaF & the 4x4 communication vehicles are situated at Marmul, Fahud and MAF.

2.4.4 Leak IsolationOnce the incident site has been safeguarded, the leak, if one has occurred, will be isolated by closing in the adjacent upstream and downstream block valve stations. The gas will be allowed to disperse through the rupture or through emergency flares/vents and by load distribution of power during the isolation and depressurising phase of the emergency. Once closed, the block valves will be injected with sealant to prevent any gas passing. If this is unsuccessful, then UIPT and UIPT/4 will be consulted for additional actions to be taken.

2.5 Assessment of LeaksA leak shall be initially assessed on the basis of the following criteria:

has the gas release ignited or not 1” dia > large … approximate size of the leak … minor ≤ 1” dia proximity of PDO or Contractor facilities or PDO roads proximity of 3rd Party habitation / public roadsRegardless of ignition or not, the leak shall only be considered minor provided that the leak size is less than 1” dia and the nearest habitation or public road is greater than 500 m from the location of the leak.

Following the initial determination of any incident, as described in this Section, under initial response guideline, the LEBC or DD may request the On-Scene Commander to undertake a secondary assessment of the Emergency Category using the guidelines below. Under no circumstances, however, will the On-Scene Commander be deflected from making the incident area safe and secure.

The following table illustrates identified risks associated with SOGL (operations starting at Saih Nihayda and ending at Harweel).

Risk Assessment of Consequences

Frequency/ Probability

Risk Band

Cumulative effect of pipeline leaks E3, R5 C ExtremeEncroachment of pipeline right-of-way A1, O5 A ExtremeRupture/loss of containment in pipelines A3, E5, P5, D3, R4 C ExtremeRupture/loss of containment in process facilities

A4, E4, P5 C Extreme

Fatality related to pig operation E3, P4 C HighSafeguarding system short comings A4, E3, P4 C High

Table 2.5 Leak Risk Assessment

2.6 Gas Leak Rate DataDistances from estimated leak location for Emergency Response Planning i.e. evacuation of non-essential personnel and members of the public from the area and access control of Emergency Response



Team by On Scene Commander with appropriate controls. Distances are based on full bore releases for the initial pipeline pressure under worst credible case conditions. As the pipeline pressure decreases, the distances to levels of concern will reduce.

Building Evacuation

Outdoor Ignition Sources

16 0.4064 75 10 2100 1520 70010 0.254 65 10 870 590 4408 0.2032 65 10 620 420 3606 0.1524 65 10 400 270 2804 0.1016 65 10 220 150 2002 0.0508 65 10 90 70 110

Distance to Level of Concern for

Ignited Releases* (m)

Distance to Level of Concern for Unignited Releases (m)#

Pipeline ID (in)

Pipeline ID (m)

MAOP (barg)

Temp (deg C)

(*)1.6 kW/m2 from jet fire inclusive of solar radiation

Table 2.6A LEL Hazardous Areas

2.7 LEBC & OSC Specific Checklist for Pipelines Emergencies

OSC Checklist for Pipeline Emergencies

Before departure, the designated OSC to ensure he takes OSC bag, full and appropriate PPE, GSM, radio and Thuraya phone if possible.

On arrival at the scene, assess the magnitude of the spill:Estimate size of rupture / pinhole and area covered by spilled fluid communicate to LEBC

Establish initial access controls to emergency site

Have an operator(s) take a portable gas detector and check around the emergency site perimeter. In the event of gas detection increase the exclusion / isolation zone.

Deploy portable gas detectors around the site, monitor for toxic as well as HC emissions Interface with LEBC regarding strategy for isolation of the leak

- Material and Staff requirements for containment- Material and Staff requirements for short term repair

Interface with ROP to evacuate any member of the public or nearby housing which may present an ignition source. Recommended minimum evacuation distance 100m

In the event of application of a foam blanket, mobilise additional foam and water supplies to replenish the fire tenders

Access Control:- Road-blocks must be set up if within 100m of a highway- The surrounding area should be cordoned off as soon as possible, use hazard warning tape (in

OSC bag) and signs if available- Site access must be continuously controlled. If possible the ROP should assist in the control of

access to the site

Designate a parking area for arriving resources / vehicles etc

Confirm with ROP on status of road isolation

Mobilise HR and External Affairs via the LEBC in the event of arrival of the media

Request refreshment for emergency crews

Identify a suitable area for temporary storage pit(s) for recovered oil

Note: In the event of any injuries at the emergency site, whether to PDO staff, contractors or 3rd

parties, the casualties must be tracked viz a viz which hospitals they have been dispatched to and the nature of the injuries. This information must be forwarded to the LEBC/LECC.



LEBC Checklist for Pipeline Emergencies

Confirm the location of the emergency- Team to take gas detector(s) and 2 x Amplitorque hydraulic power packs, BA sets- Team to have vehicle with Thuraya phone, Radio and GSM

Dispatch an OSC with radio, Thuraya and the OSC bag

Confirm Fahud & QA CCR's and Nahada Booster station are on standby

Get an estimate of the magnitude of the spill Interface with Pipeline Engineers re - strategy for isolation of the leak (Ref Section 4.3)

- Emergency Shut Down RUPTURE- Controlled Shut Down LARGE LEAK- Increase flow rate and clamp PINHOLE (Downstream of HP)

Advise the OSC on area to be isolated. Recommended minimum evacuation distance 100m

Determine how much crude will still escape following shut down and mobilise containment support for the OSC

If necessary dispatch sufficient gas detectors to establish a secure perimeter around the site

Mobilise HR and External Affairs via the LEBC if in a populated area or in the event of arrival of the media

Dispatch HR and Security representation to interface with ROP and public ESPECIALLY IN THE EVENT OF THE OSC BEING A NON ARABIC SPEAKER

In the event of application of a foam blanket, mobilise additional foam and water supplies to replenish the fire tenders

Mobilise earth moving equipment if required - bulldozers / diggers / etc

Mobilise vacuum trucks and additional manpower

Decide on optimum waste disposal points

If required mobilise liners for temporary storage pit(s) for recovered oil

Instruct mobilised resources to go to designated parking areas on arrival and to report to the OSC

In the event of public evacuation, instruct the CECC to take over interfaces with the ROP except at site level

Mobilise External Affairs, if in a populated area or in the event of arrival of the media.

In the event of extensive clean up and / or repair mobilise the Communications Trailer and personnel cleaning facilities (toilets / wash points etc)

Organise refreshment for emergency crews

If required mobilise liners for temporary storage pit(s) for recovered oil

2.8 Stand Down of the Emergency TeamOnce a stand-down of the Emergency Team has been initiated, the LEBC will hand over the emergency site to the asset holder who will manage the business recovery activities.



3 South Oman Gas Line Technical Details

3.1 Asset OverviewThe South (and Central) Oman Gas Line (System), is comprised of the gas suppliers and treatment facilities in the Central and Southern regions, together with the export line to the Southern region. The export line, nominally 600# classification, consists of several sections; a 297 km section of 9270 kPa rated 16" line running from Saih Nihada to Hubara, a 159 km section of 6800 kPa rated 18" line running from Hubara to Marmul and an 80 km section of 9270 kPa rated 16" line running from Harweel to Marmul. The 18" line is split into two sections: 108 km from Hubara to Amal Power Station and 51 km from Amal to Marmul. Between Hubara and Nimr the 18" pipeline is rated to 9270 kPa. South of Nimr the pipeline, which was originally used as the MOL-01 oil pipeline, is rated only to 6800 kPa. Pressure letdown and over pressure protection is provided at Hubara to protect the low rated portion of the 18" pipeline.

3.1.1 SOGL Gas SuppliersThere are multiple exporters of treated gas into the line. The primary source of gas into SOGL is from the 48” Gas Line SRCPP/SNGP – OLNG. Additional suppliers are Zauliyah, Al-Noor and Harweel stations. Emergency back-up gas is available from the Southern Interconnector which can supply up to 1.0 million m3/d gas from OGC via the line to Mukhaizna, located near Sadad station.

Government Gas comes off the 48” lines SRCPP/SNGP – OLNG at KP 24.5 and ties into SOGL. A pressure control valve with flow override is provided at the off-take from Government Gas to regulate the supply of gas to SOGL. No pressure protection is provided, since the 16" SOGL pipelines running from KP24.5 all the way to Hubara are fully rated with respect to the Government Gas system.

The 5km 10" Northern Interconnector from KP24.5 to the redundant Saih Nihayda Gas Treatment Plant has been retained as an alternate route for supply of treated gas to consumers at Saih Nihayda / Ghaba North / Qarn Alam apart from the 16" SOG-01 pipeline.

Zauliyah Production Station is situated 30km West of the MOL Sahma Booster Station and receives crude product from Hasirah Gathering Station (25km West of Zauliyah) and the smaller fields of Hazar, Hawqa and Maqtaa. The associated gas from these fields is also available for export. The net volume of excess gas available for export from these facilities is dependent on consumption, but is approximately 200,000m3/d. There are development plans for the Zauliyah area that could nearly double the amount of gas available for export to SOGL.

The Southern Interconnector is located just north of Hubara Booster Station and comprises 600 m of 12 inch piping. This piping connects the 18" SOGL-23 pipeline carrying OGC gas from the Salalah Gas Pipeline to the Mukhaizna Power Station to the 16" SOGL-04 pipeline nearby Sadad production station. In the event of falling SOGL pressure at Marmul Main Production Station it is possible to open the Southern Interconnector and supply up to 1 million m³/d to SOGL (on a temporary basis). The standing agreement between PDO and OCG allows PDO to take gas up to 10 days per year on an emergency basis. Hence, the Southern Interconnector functions as emergency back-up for SOGL.

Marmul associated gas is collected, compressed and used as fuel in the Marmul Power House and Marmul Main Production Station (MMPS). This gas does not enter the SOGL system but reduces the demand for gas supplied from SOGL to MMPS. (There is a plan to retire the power generators at Marmul Power House, treat the associated gas and export it to SOGL. The facilities are expected to be commissioned in about 2017.)

Al Noor Production Station (ANPS) is situated around 55 km south west of Nimr area. It extracts the associated highly concentrated H2S gas from Al Noor and Alshamu fields crude product, the gas is treated for H2S content, (less than 10 ppm product), and is dew pointed for water and hydrocarbon to 10°C at 6,000 kPa. The product is directly exported to SOGL. It has a single gas treatment train with a designed capacity of 700,000 m3/d. However the actual treatment capacity of the plant is around 650,000 m3/d. with an export rate of 400,000 m3/d.



Harweel Production Station is located around 80 km west and a little south of Marmul. Most of the highly sour gas from the reservoir is recompressed and injected into the reservoir for enhanced oil recovery, but a side stream is sweetened, dew pointed and exported to SOGL. The maximum treatment capacity of the gas plant is about 2.2 million m3/d with about 500,000 m3/d consumed for fuel to run the plant. Normal export to SOGL is 500,000 to 700,000 m3/d. The gas pipeline from Harweel to Marmul is sized for the case when the injection compressor is down and the maximum treated gas is exported to SOGL – i.e., roughly 1.8 million m3/d. This design allows Harweel to continue to produce some oil without having to flare the associated gas when the gas injection compressor is down.

Kaukab high GOR crude product is exported to Birba Gathering Station where the associated gas from this field, together with Birba associated gas, is used for gas injection into the Birba reservoir. SOGL gas is no longer required at Birba to support gas injection.

Although the individual export flows are measured, and most of the consumers off-takes are measured, the total mass volumes of gas cannot be accurately measured due to the inherent deficiencies in the overall SOGL monitoring systems. On a daily basis, errors in the balance of gas export and consumption are of such magnitude that detection of a major leak would not be possible with the installed instrumentation.

The following tables list the Gas Exporters and Consumer/exporters discharging into the SOGL.

Gas Export Distribution (Sep 2013 – looking towards PB 2014)

Supply

Location Input Quantity (10³ m³)

Min Press (barg)

Max Press (barg)

Government Gas at KP 24.5 (SR CPP/SNGP)

2800 75 92

Zauliyah GTP 200 64 72

Al Noor GTP 300 40 60

Marmul (to Marmul power

plant)

Harweel 650 50 65

Southern Interconnector

Backup 64 72

Total (not incl Intercon.) 3950 -- --Table 3.1.1C Gas Availability

3.1.2 SOGL Gas ConsumersThe primary consumers of SOGL gas are the power stations in the Central and Southern regions.

SOGL gas is also used as fuel gas for lift gas compressors, generators and crude oil heaters, blanket and purge gas, and as back up lift gas.

The available gas has to be shared among consumers in the Central and Southern regions. The gas distribution system in the Northern region does not connect to the SOGL system. Power generators at Saih Rawl CPP are supplied directly from CPP and do not connect to SOGL, either.

North Oman Directorate (Central Oman area)

Power Generation: There are two main gas consumers in Central Oman, Saih Nihayda Power Station which comprises a single Frame 6 turbine driven generator set, consuming 220,000 m3/d of



fuel gas on full power. Qarn Alam Power Station consist of two frame 6FA turbine driven generators consuming around 600,000 m3/d and two frame 9E turbine driven generators consuming up to 1,500,000 m3/d.

Production: Ghaba North and Al Ghubar currently use a small quantity of SOGL gas as lift gas. SOGL gas is also used as back-up for the Qarn Alam Steam lift gas compressor and for supplemental firing in the Heat Recovery Steam Generators for QA Steam. The other Central Oman consumers use minor amounts for blanketing and fuel purposes.

South Oman Directorate

Power Generation: The primary gas consumers in the South are the seven power stations: Suwaihat, Nimr, Marmul, Rima, Hubara, Amal and Haima West. Marmul has three Frame 5 turbine driven generators, Rima has two F5’s, each consuming approximately 150,000 m3/d of fuel gas on full power. Marmul has a secondary fuel gas supply, derived from the Marmul associated gas facility, but this alone is not sufficient for normal levels of Marmul power generation. Rima is, however, totally dependent for fuel gas on the SOGL system. Both power stations have a back up diesel fuel system, but this is not considered a sustainable source due to the logistics of diesel replenishment. Present stocks and actual diesel tank capacities allow less than 24 hours of running at normal power generation levels.

Hubara has three Frame 6 turbine driven generators, whereas Haima West consists of one large Frame 6FA turbine, capable of providing 550 MW.

One Frame 6 turbine driven generator set in Suwaihat, not having any back-up, is dependent on the SOGL. Two Frame 6 turbine driven generator sets in Nimr do not have alternative fuel gas supply.

Amal power station comprises two Frame 9E gas turbine driven generator sets, each with a capacity of approximately 100 MW. With the commissioning of the two Frame 9E generators at Amal power station the burden of power generation in South Oman is being shifted away from the smaller gas turbines to the larger, more efficient F9E turbines.

Production: The largest consumer of SOGL gas in the South is the Nimr Production Station, where the gas is used for fired heaters and tank blanketing.

Anzauz and Zauliyah have some associated gas that can be treated and exported to SOGL, but the amount of gas available at Anzauz is minmal and SOGL is actually imported at Anzauz, since its gas treatment facilities are no longer in service. Associated gas from Zauliyah is compressed and used for lift gas and fuel purposes within its own facilities. Excess gas is treated and exported into the SOGL. The volume of gas available from this station is relatively small, but there are development plans for the area that may lead to an increase in the amount of gas exported to SOGL.

Suwaihat and Bahja are supplied with SOGL gas via a common 6" line into the Suwaihat block valve station. Their present use of SOGL gas is only for pilot, blanketing and purge purposes.

Sayyala requires gas from the SOGL for pilot, blanketing and purge purposes.

Rima is a large consumer of SOGL gas due to the Rima power house, with a lesser demand for the production station crude oil heaters and blanketing and purge gas.

Nimr Production Station has gas fuelled crude oil heaters together with purge and blanketing gas requirements.

Marmul area has its own gas collection system and would be independent of the SOGL, if not for the high consumption of the Marmul power house. The Marmul gas collection system comprises of a low pressure gas recovery compressor, installed at MMPS under the Marmul Central Development Project Phase 2 (MCD-2). Two high pressure gas compressors situated in the MPS supply sufficient gas to fuel one of the Frame 5 power turbines.

The following table summarises consumers dependent on the SOGL system. Consumption as of March 2014.



Demand

Location Demand Quantity (10³ m³)

Min Press (barg)

Max Press (barg)

Saih-Nihayda Power Stn 154 25 40

Qarn Alam Power Stn 1400 55 80

Suwaihat Power Stn. 154 25 40

Suwaihat Prod. Stn. 2 25 40

Sayyala Production Stn 2 25 40

Sadad Production Stn. 1 25 40

Hubara Power Station 200 25 40

Rima Production Stn. 35 25 40

Rima Power Station 100 25 40

Nimr Production Stn. 95 25 40

Nimr Power Station 200 25 40

Amal Power Station 1100 30 60

Marmul Production Stn Self Supplying 25 40

Marmul Power Station 100 16 25

Haima West Power Stn. 400 30 60

Birba Production Stn. 2 16 25

Total 3945

Table 3.1.2 Gas Consumers



Figure 3.2 South and Central Oman Gas Line Suppliers and Consumer



3.2 Pipeline SpecificationsDetails are shown in the SOGL Schematic System Map. For further information it is recommended to refer to UIPT/1/11 (conceptual design, capacity), UIPT/3 (system management), UIPT/4 (pipeline services), UIPT/6 (technical integrity).

The MAOP (Maximum Allowable Operating Pressure) is as follows:

For Pipeline 16” size design MAOP = 92.7 bar g For Pipeline 18” size design MAOP = 68 bar g

3.2.1 Pipeline Classification

SOGL section

Code Pipeline Diam. Inches

Length km

*MAOP Bar

ANSI Rating #

Material Grade

SOGL-01 GQST01 Saih Nihayda - Sahma 16 149 92.7 600 API 5LX60

SOGL-02 GQBI01 Barik – MGL (mothballed) 6 6 93 600 API 5LX60

SOGL-03 GQLI01 MGL - Al Ghubar 6 24 95 600 API 5LX42

SOGL-04 GSPT01 Sahma – Hubara 16 148 92.7 600 API 5LX42

SOGL-05 GSZI01 Sahma – Zauliyah 6 35 95 600 API 5LX42

SOGL-06 GQNI03 MGL – Anzouz 4 15 95 600 API 5LXxx

SOGL-07 GSUI01 MGL – Suwaihat 6 9 95 600 API 5LX42

SOGL-08 GSBI01 Suwaihat – Bahja 6 9 95 600 API 5LX42

SOGL-09 GSSI01 MGL – Sayyala 8 55 83 600 API 5LX42

SOGL-10 GHSI01 MGL – Sadad 2 0.2 tba 600 API 5LX46

SOGL-11 GHPT02 Hubara – Rima 10 32 73 600 API 5LXxx

SOGL-12GHPT01

Hubara – Marmul (abandoned) 10 159 65

600 API 5LX52

SOGL-13 GNPT01 MGL - Nimr NRPS 6 0.3 65 600 API 5LX60

SOGL-14 GNYI01 MGL – Amal 2 1 95 600 API 5LX42

SOGL-15 GMPI01 Marmul – Birba 10 23 48 600 API 5LX42

SOGL-16 GBSI01MGL-Mukhaizna (Handed over to OXY) 3 30.5 95

600 API 5LX46

SOGL-17 OMARTT01 Al-Noor-SOGL 10 37 80

600 API 5LX46

SOGL-18 GMHT01 SOGL-Haima West 8 5 95 600 API 5LX46

SOGL-19 GQSI03 Saih Nihayda – QA Power Station

10 21 95 600 API 5LX80

SOGL-20 GBPT01 Hubara – Amal Power Station

18 108 68 600 API 5LX60



SOGL section

Code Pipeline Diam. Inches

Length km

*MAOP Bar

ANSI Rating #

Material Grade

SOGL-21 GNPT03 Amal Power Station – Marmul

18 51 68 600 API 5LX60

SOGL-22 GHRI01 Harweel – Marmul 16 80 92.7 600 API 5LX60

SOGL-24 XXXX Saih Nihayda – QA Power Station

12 21 92.7 600 API 5LX60

SOGL-25 Hubara – Hubara Power stn

8

SOGL-26

SOGL-27

Table 3.2.1 Pipeline Classification

*MAOP cannot be guaranteed to be correct. Livelink should be consulted (or contact UIPT/3 and UIPT/32)

3.2.2 Pipeline Volume dataThere are no isolation block valves at the Non Return Valve points on the SOGL. The NRV's may prevent back flow to a leak upstream of the NRV, but they are not fail safe. It should be assumed that the potential leak volume is the capacity of the line between the upstream and downstream isolation block valves.

Pipe Diameter Inches Wall thickness m³ per km of pipe18 7.1 154.1218 6.35 155.1816 7.1 120.8110 5.6 53.858 4.8 34.466 4.8 19.774 4.8 8.612 4.8 2.02

Table 3.2.2 Pipeline Volume Data

3.2.3 Line Capacity between Isolation PointsFrom To Length

kmLine size inches Wall thickness

mmVolume m³

Saih Nihayda (KP24.5) SOGL01-BVS01 29 16 7.1 3503

SOGL01-BVS01 SOGL01-BVS02 30 16 7.1 3624.0

SOGL01-BVS02 SOGL01-BVS03 18 16 7.1 2175.0

SOGL01-BVS03 SOGL01-BVS04 26 16 7.1 3141.0

SOGL01-BVS04 SOGL01-BVS05 22 16 7.1 2658.0

SOGL01-BVS05 Sahma 24 16 7.1 2899.0

Sahma SOGL04-BVS01 25 16 7.1 3020.0

SOGL04-BVS01 SOGL04-BVS02 29 16 7.1 3504.0

SOGL04-BVS02 SOGL04-BVS03 33 16 7.1 3987.0

SOGL04-BVS03 SOGL04-BVS04 31 16 7.1 3745.0

SOGL04-BVS04 Hubara 30 16 7.1 3624.0

Hubara SOGL20-BVS01 40 18 7.1 6165



From To Length km

Line size inches Wall thickness mm

Volume m³

SOGL20-BVS01 SOGL20-BVS02 35 18 7.1 5394

SOGL20-BVS02 Amal 33 18 6.35 5121

Amal Marmul 51 18 6.35 7914

Harweel SOGL22-BVS01 40 16 7.1 4832

SOGL22-BVS01 Marmul 40 16 7.1 4832

SOGL Barik 6 6 4.8 119.0

SOGL Al Ghubar 24 6 4.8 475.0

SOGL Anzauz 15.0 4 4.8 129.0

SOGL Zauliyah 35.1 6 4.8 694.0

SOGL Suwaihat 9.0 6 4.8 178.0

Suwaihat Bahja 9.0 6 4.8 178.0

SOGL Sayyala 55.0 8 4.8 1895.0

SOGL Sadad 0.2 2 4.8 0.4

Hubara Rima 32.0 10 5.6 1723.0

SOGL Runib 3.0 2 4.8 6.1

SOGL Nimr 0.3 6 4.8 5.9

SOGL Amal 0.9 2 4.8 1.8

Marmul Birba 23 10 5.6 1239

Table 3.2.3 Line Capacity between Isolation Points



4 Emergency Repairs

4.1 System PreparationAll activities relating to system preparation will normally be performed by UIPT/4 personnel or operations personnel with relevant pipeline experience. Subsequent work, e.g. earth moving, will be performed only when authorised by the UIPT/4 site representative (CSR).

Before any work can be carried out on a pipeline, the pipeline is required to be made safe.

4.1.1 Line Isolation and DepressurisationTo isolate the pipeline effectively, the adjacent upstream and downstream block and bypass valves to the gas leak area will be closed and sealed. To enhance safety during the emergency repair phase, the next nearest upstream and downstream block and bypass valves will also be closed and sealed affording a double block both upstream and downstream of the leak area. If positive isolation cannot be achieved, the UIPT/4 site representative will be informed. The UIPT/4 site representative will determine additional requirements to obtain full isolation.

Depressurisation of isolation zones will commence on the instruction from UIPT/3 and UIPT/4 via the on-site, UIPT/4 site representative. All venting will be carried out at suitable block valve station bypass locations where no danger exists to personnel within the venting area from the vented gas quantities. The isolated section will then be depressurised by installing a vent stack on the block valve station vent valve and opening the vent valve. If possible, station flares on both the upstream and downstream block valves should be used to decrease blowdown time.

4.1.2 Line DegassingBefore any repair work (e.g. to allow the installation of a PLIDCO clamp) can proceed, the isolated pipeline section must be confirmed gas free unless agreed otherwise by UIPT/3 and UIPT/4. There must be no explosive mixtures of gas and air. The gas inventory in the isolated section will be removed using air-powered blowers located at the block valve station vents. Ideally, air blowers should be located at both block valve stations and the air allowed to escape through the rupture. If only one air-powered blower is used, the other block valve station vent should be open to increase the amount of air drawn into the pipeline.

An alternative approach will be to purge the isolated line section with nitrogen. If the line is leaking, nitrogen shall be injected at the upstream and downstream block valve station and merged from these two locations towards the ruptured section.

The leak location and block valve station vents will then be tested for gas. Only when all three locations indicate no gas can the line be declared gas free. Continuous gas testing must be performed throughout the period of the repair. In case of a small leak, the nitrogen can be supplied via the bypass line (vent stack connection) of the valve station and vented at the other isolation valve.

4.1.3 Specialist Repair Resources:

Service South / Central OmanPipeline Operations UIPT/3Service Contracts OXE/3XPipeline Repair UIPT/2, UIPT/4Earth Moving Services OXE/34XSupply Logistics (Operations, Aerial Search) UWLEnvironmental Affairs MSE/2Technical Services, Pipeline Services UIPT, UIPT/2, UIPT/1

Table 4.2.7 Specialist Repair Resources



4.1.4 SOGL Leak Repair Response

Flowchart notes SOGL Leak Repair.

1 Any necessary clamps and other equipment should be sourced and delivered to the site. The construction repair crew will be organised by OXE/3X assisted by the pipeline operations / maintenance section, UIPT/4.

2/3 On an extended repair, it will be necessary to provide facilities for the response personnel on site. Toilet and washing facilities and one of the portable telecoms trailers could be sent to the site. It will also be necessary to arrange shifts of workers, which may involve bringing in PDO and Contractors staff from other areas. Accommodation in the nearby PDO and Contractors’ camps may be a problem due to the extra staff involved. Use of PDO's Contractors’ remote camps or civil facilities; motels, restaurants etc., should be considered if convenient.

3/4. The detailed repair procedure is covered in the Emergency Repair Manual. Pipeline Repair materials (Emergency Stock) are kept at various PDO locations (MESC coded group 99). Stand down from a SOGL emergency will probably be gradual, initially standing down the higher levels as the situation comes under control. The priority will then be the environmental clean up and restoration of the site. The environmental impact will be reported as per the Incident Investigation Reporting and Follow-up Procedures and Guidelines (SRD/P/01).


LEBC

1 2 3 4 5 6

Symbols:

Activity

Decision

Start/End

Meeting Attendee

Return from/forwardto another activity

ContinuationST E

Abbreviated Activity DescriptionNo.

MA

Commence excavation of buried line.

Repair leak, resume operations.

Stand down emergency team, initiateenvironmental cleanup.

Business Resumption Plan.

Resource pipeline repair kit and crew.

If repair crew will take long time arrangefacilities for crew.

This repair procedure is covered in the emergency repair manual, it is to be used in conjunction with individual pipeline technical information sheets

E E

ERe

pair

Crew

Area

Sup

ervi

sor

OSC

1

2

3

4

5

6

LEBC

1 2 3 4 5 6

Symbols:

Activity

Decision

Start/End

Meeting Attendee

Return from/forwardto another activity

ContinuationST E

Abbreviated Activity DescriptionNo.

MA

Commence excavation of buried line.

Repair leak, resume operations.

Stand down emergency team, initiateenvironmental cleanup.

Business Resumption Plan.

Resource pipeline repair kit and crew.

If repair crew will take long time arrangefacilities for crew.

This repair procedure is covered in the emergency repair manual, it is to be used in conjunction with individual pipeline technical information sheets

E EE E

ERe

pair

Crew

Area

Sup

ervi

sor

OSC

1

2

3

4

5

6


5 Business Resumption The SOGL is the only means to transport fuel gas to interior operating locations providing power to the production stations and the MOL Booster Stations. Repair to the SOGL, is a priority and must be completed without delay before normal operations can resume.

Once the gas leak is stopped, focus should change to the repair project by engineering as per the Pipeline Emergency Repair Manual.

Repair work should be done on a 24 hour a day basis and to the required standard until authorisation can be given to resume normal operations.

Before start-up, open the block valves, pack the pipeline, ensure that no air-pockets are left in the line, start-up slowly, confirm all operations normal, increase to full flow.

5.1 Failure mechanismsPossible failure mechanisms that would result in non availability of SOGL gas to the consumers are:- 1. Export failure of one or more of the gas suppliers.2. Failure at some point on the gas supply line, probably resulting in a leak.

(Will normally only affect those consumers downstream of the closed in section of line.).

3. Contamination of the gas line which may causing blockages within the consumer facilities.4. Obstruction of the gas line probably by a stuck pig.

5.1.1 Failure of a Gas Supplier.The only Gas Supplier Failure that meets BRP Criteria is the total loss of Government Gas supply at KP24.5. For this reason, the control valve installed at the off-take from the Government Gas system is modulated by instrument gas (instead of instrument air) and designed to fail open on loss of pneumatic supply.

Saih Nihayda Gas Treatment Plant

Saih Nihayda Gas Treatment Plant has been made redundant and is no longer supplying gas to SOGL.Barik

No longer gas supplier to SOGL.

Al-Noor

Failure of the gas export into SOGL from Al-Noor at 400,000 m3/d, is not likely to have a major impact on the gas consumers unless it fails at the same time as one of the other producers.

Anzauz

No longer gas supplier to SOGL.

Zauliyah

The SOGL system does not depend on Zauliyah to be a constant gas producer as its input to the system is minor compared to the quantity imported from Government Gas at KP24.5. For this document it is assumed that in any SOGL failure Zauliyah station will remain independent of any external gas requirements.

Harweel

Failure of the gas export into SOGL from Harweel was one of the design scenarios considered under the project to replace the corroded 10" SOG-12 pipeline from Hubara to Marmul. In the event of failure of supply from Harweel the SOGL system should be able to maintain the minimum required pressure at the Haima West power station. If Harweel and Al-Noor fail at the same time and the pressure falls below 40 bars at Marmul, there is emergency back-up gas available from OCG via the Southern Interconnector near Sadad to help maintain the pressure in the system. Under the terms of the agreement with OGC PDO may take up to 1 million m³/d of gas import for up to 10 days per year for emergency pressure support in SOGL.

5.1.2 Leak on the Gas LineThe major considerations during a leak on the SOGL line will be the HSE issues covered in the Emergency Response Contingency Plans. The implications for gas supply to the consumers is shown in Table 3.



5.1.3 Contamination of the GasInternal contamination of the gas which is likely to have a detrimental effect on the downstream consumers, is normally caused by corrosion products, dislodged during pigging operations. At every off-take, there should be a filter to protect the equipment/facility, frequency of blocking of these filters being dependent on gas consumption. Cleaning of these units creates a time consuming and potentially production deferring situation. Filters have been installed in the power stations and in the more critical Production facilities.

5.1.4 Obstruction of the Gas LineStuck pigs are a risk particularly following a period of reduced pigging activity (or introduction of a more aggressive pigging procedure). Use of tracking pigs is advised in critical situations to allow rapid location of a stuck pig. All Main Oil and Gas lines are pigged regularly, reducing the risk of an accumulation of debris and thus a stuck pig. For all SOGL (and Main Oil Line) pigging, pigs with locators are used.

The consequences of any of the above failure mechanisms are the same, loss of gas to downstream consumers. The impact of the loss of gas is dependent on the criticality of the facility and its ability to operate without the gas supply.

5.2 Impact of loss of gasThe criticality of the failure of part of the SOGL system, is dependent on the location of the failure. Generally, the further upstream in the system the failure occurs, the greater the impact. For a SOGL line failure there should be no deferment north of the point of isolation as Saih Nihayda Gas Plant should remain on line.

Gas supply to individual sources has been prioritised in the following manner:

Supply Shortfall - Priority for SOGL Gas AllocationPrecedence 1. Power Stations

2. Individual Production StationsNotes

Should a shortfall in the SOGL gas supply (pressure dropping below 40 barg at Marmul) the following steps shall be taken:

Investigate reason for shortfall - [coordinated by UIPT/3] Open Southern Interconnector – [notify OGC of gas off-take] Verify potential to reduce gas consumption at southern power stations (through UIE/3)

This must be done without endangering the stability of the grid or the integrity of the turbines.

Note that there is only limited scope for reducing gas consumption in this manner. Implement load shedding at facilities in south Halt the supply of gas to individual stations, as necessary.

The criticality of the gas supply is high in the case of fuel gas for the Power House(s), though quantifying this is not possible as there is no simple conversion formula between generated power and net produced oil due to the differences in lift method, BS+W, processing etc. As selective load shedding will be updated continuously during a power outage, the available power will be optimised to maximise net production. Following optimisation, 40% of normal power should be able to produce, treat and export 60-70% of normal production.

An extended shut-down of the SOGL gas will leave insufficient capacity in the PDO System. Load shedding will be required and line pack will allow a limited number of hours to achieve this. Optimisation involves shutting down a lot of non production facilities, workshops, camp leisure facilities, field lighting etc, however ultimately very significant deferment may be caused.

While the original design of Power Houses gas turbine installations provided a back-up diesel fuel supply to cover failure of the gas system, as production levels have increased, upgrade of the diesel facilities has not been maintained with the result that these facilities are no longer considered as credible back-up.

Table 3 lists the critical facilities and how they would be affected by isolation of the SOGL at the isolation points (Block Valve or Booster Stations) along the line. As a minimum, all of the scenarios involve loss of Government Gas supply on isolation of BVS-1.



Table 3Gas exporters below isolation point

Critical Facilities below isolation point.

Means of Recovery.

Isolation Point SOGL01-BVS01 orSOGL01-BVS02Available Gas Supply:Marmul gas grid in Marmul area, Zauliyah, Al Noor, Harweel & Southern InterconnectorAvailable gas:- xx,000m3/d.

All power generation in the South is affected, other than Haima West, Nimr and the two or possibly one Marmul Frame"5" running on Marmul gas. Nimr heaters and Sayyala and Suwaihat gas lift compressor drivers are affected.

Maximise the load on the Marmul, Haima West and Nimr Power Stations with the gas available from AL Noor, Harweel and Marmul associated gas. Nimr heaters and gas lift drivers are fuelled on the Zauliyah gas. Rima power turbines switch to diesel fuel.

Isolation Point: SOGL01-BVS03,SOGL01-BVS04,SOGL01-BVS05.Available Gas Supply:Marmul gas grid in Marmul area Zauliyah, Al Noor, Harweel, Southern Interconnector & Linepack

All scenarios are as above for SOGL01BVS1 or BVS02.

Maximise the load on the Marmul, Amal, Haima West and Nimr Power Stations with the gas available from AL Noor, Harweel, Southern Interconnector and Marmul associated gas. Nimr heaters and gas lift drivers are fuelled on the Zauliyah gas. Rima power turbines switch to diesel fuel.

Isolation Point: Sahma Booster Station or SOGL04-BVS01Available Gas Supply:Marmul gas grid in Marmul area Al Noor, Harweel, Southern Interconnector & Linepack.

Power generation is as above.Nimr heaters and Sayyala and Suwaihat Gas lift compressor drivers are affected.

Maximise the load on the Marmul, Amal, Haima West and Nimr Power Stations & Nimr heaters and Gas lift with the gas available from AL Noor, Harweel, Southern Interconnector and Marmul associated gas.Rima power turbines switch to diesel fuel.

Isolation Point: SOGL04-BVS02 orSOGL04-BVS03Available Gas Supply:Marmul gas grid in Marmul area Al Noor, Harweel, Southern Interconnector & Linepack.

Power generation is as above but the Suwaihat Frame"6" has fuel gas. Hubara & Rima Power Stations and Sayyala gas lift compressor drivers are affected.

Maximise the load on the Suweihat, Marmul, Amal, Haima West and Nimr Power Stations & Nimr heaters and Gas lift with the gas available from AL Noor, Harweel, Southern Interconnector and Marmul associated gas.Rima power turbines switch to diesel fuel.

Isolation Point:SOGL04-BVS04Available Gas Supply:Marmul gas grid in Marmul area Al Noor, Harweel, Southern Interconnector & Linepack.

Power generation is as above with the Suwaihat Frame"6" normal. Nimr heaters are affected.

Marmul third power turbine switches to diesel fuel. Maximise output from the Suwaihat Frame "6".Nimr heaters are fuelled on the SOGL linepack. If sufficient power is available from North Oman, shutdown the Marmul diesel fuelled power turbine(s).

Isolation Point: Hubara Booster or SOGL20-BVS01 or SOGL20-BVS02Available Gas Supply:Marmul gas grid in Marmul area Harweel, Al Noor & Linepack.

No major impact, provided Al Noor and Harweel supply on line.



As seen in the table above, Nimr heaters may depend solely on the SOGL linepack. The further north the isolation point, the greater the linepack capacity of the isolated section. Table 4 assumes Nimr heaters consume an average of 4,000 m3/hr, and there are no other consumers from the isolated section of the SOGL. The number of hours running time is based on drawing down the line pressure by 1000kpa. If the line is isolated at SOGL04-BVS01, and the pressure allowed to drop from 7000 to 1000kpa, in theory Nimr heaters could run for 360 hours (15 days) on linepack alone.

Table 4IsolationPoint

To Capacity ofisolated sect.

Run Nimr Heaterson linepack for:- In such a case with the isolation at BVS-6, if the

shutdown is likely to be less than 10 days, other facilities could also draw off the linepack. With Sahma running normally, Hubara Booster pumps and Nimr heaters could draw from the linepack under the same circumstances; ie from 7000 to 1000 kpa for 8.5 days running.

SOGL04-BVS01 Marmul. 24,000m3 60 hours/1000kpaSOGL04-BVS02 Marmul. 20,000m3 50 hours/1000kpaSOGL04-BVS03 Marmul. 16,000m3 40 hours/1000kpaSOGL04-BVS04 Marmul. 12,000m3 30 hours/1000kpaHubara Marmul. 8,000m3 20 hours/1000kpaSOGL12-BVS01 Marmul. 6,500m3 15 hours/1000kpaSOGL12-BVS02 Marmul. 5,000m3 12 hours/1000kpa

5.3 Load Shedding for Southern region

AUTOMATIC LOAD SHEDDING TABLE St-1:48.8 HZ, St.-2: 48.6HZ, St.-3: 48.4HZ, St.-4: 48HZ SOUTH OMAN

Description of load

KW Remarks

Stage-1 Stage-2 Stage-3 Stage-4

Anzauz 455 0 0 0 K7802Anzauz 455 0 0 0 K7803Bahja 60 0 0 0 Water wellBahja 480 0 0 0 Contractors campBahja 300 0 0 0 PDO campRima 1200 0 0 0 Reactor & 11kV ring s/s-ARima 1200 0 0 0 Reactor & 11kV ring s/s-CRima 0 4000 0 0 P1310 (DWD) Rima 0 3700 0 0 P1320 (DWD) Nimr West 4082 0 0 0 P-9310 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 4082 0 0 0 P-9320 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 4500 0 0 0 P-9410 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 4500 0 0 0 P-9420 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 4500 0 0 0 P-9510 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 0 4500 0 0 P-9530 (DWD) u/f trip with df/dt>0.5HZ/sNimr West 0 4500 0 0 P-9540 (DWD) u/f trip with df/dt>0.5HZ/sNimr W-NGS 0 4679 0 0 P-4894,4895,4896, 4859,48111,

48112,48117, 48118, 48119, 4811x, 4811x, 48145, 48146,u/f trip with df/dt>0.5HZ/s

Nimr W-NGS 0 2224 0 0 G4810 (Tx-003)&G4811(Tx-004) u/f trip with df/dt>0.5HZ/s

Nimr W-NIS 0 1668 0 0 B5 (Feeder to airstrip) u/f trip with df/dt>0.5HZ/s

Nimr-W-NPr.S

0 0 5855 0 P-4807, 4811, 4847, 4814, 4816, 4841, 48113, 4868, 48142, 48143, 4809, 4849, 4815, 4818, 4824, 4848, 48125, 4870, 4871, 4869, 48144, 48145

Amal 0 0 0 7210 C-100 to Amal gath.stn. sw.rackAmal 812 0 0 P-2014 & P-2015Amal 1218 0 0 P-2007, 2008, 2009



Description of load

KW Remarks

Stage-1 Stage-2 Stage-3 Stage-4

Marmul 0 3904 0 0 Birba feederMarmul 0 0 5478 0 Marmul field ring-1Marmul 0 7200 0 0 Marmul-A 33kV switchrackMarmul 0 2312 0 0 P-1520Marmul 450 0 0 0 6.6kV RING S/S-6Marmul 1097 0 0 0 6.6kV RING S/S-7Marmul 0 439 0 0 PM2807Marmul 0 678 0 0 P-3121, 3122, 2391, 2392Marmul 0 0 158 0 KM-2512Birba 0 0 2412 0 K-3652, 3659Birba 0 776 0 0 K-3651TOTAL 29391 40580 13903 7210

Priority Listing for Consumers Based on Deferment Impact

Position of the two South Oman Booster stations in the table above, is dependent on the upgrade of the diesel facility and availability of diesel fuel.

5.4 Ensuring Business ContinuityAlternative Fuel Source for Power Generation and Booster Stations.

The provision of diesel fuel to the Power Houses is a logistics issue, compounded by a lack of storage capacity.

Power Generation

Marmul Power Station has a diesel storage capacity of 800m3, Rima has 500m3. This fuel is also used for the diesel driven fire pumps in each location. Each Frame "5" requires 0.65m3 of diesel per MW/hr, hence with all turbines running at maximum power this diesel stock will last for less than 24 hours in each location.

In the Marmul and Rima Power Houses, change over to diesel fuel is practised every week; but is frequently not totally successful particularly when the units are on a high loading. It can be expected that with a real fuel gas failure, at least one of the turbines in Marmul and possibly Rima, will fail to change over. Automatic load shedding will protect the other units which have successfully changed over.

Once the extent and estimated duration of the fuel gas shut-down is established, Supply Department is to be requested to supply the required quantities of diesel.

Delivery of diesel to the Power Houses is normally direct from the diesel supplier (Shell Markets) in 32m 3

road tankers. Offloading is by fixed pumps at a rate of approximately 20,000 litres/hour.

During extended running on diesel fuel the Power Houses will require 24 hour manning by regular staff.



SOGL Failure BRP Flowchart.

Assumes a failure of the gas suppliers or the export line. The repair is estimated to take several days to complete.

In an average situation, there will be several hours before the line pack pressure is reduced to the point that any of the consumers will trip on low gas pressure. The BRP assumes that the decision to close in all gas injection and gas lift consumers has been agreed.

At the earliest opportunity, the affected Power and Booster Station(s) switch to an alternative fuel source (or shut down) to sustain the gas supply for the critical consumers, which do not have any alternative source.

If the isolation point on the SOGL permits, the export from Al Noor, Anzauz and Zauliyah should be used to assist in maintaining SOGL line pressure. With no supply to the line, the volume of the linepack available for use is dependent on the length of line and whether it is 10", 16" or a combination of both. Table 5 in section 3.2.3 lists the isolated sector capacities.

It is assumed Marmul Power House will be operated to the limit of the Marmul gas supply, and Southern Powers House - capable of running on diesel - closed in after 24 hours (current diesel stock). The North South Power interconnector should cover the power deficiency as Saih Nihayda Power station is independent on the SOGL system.


3

Establish which consumerswill be affected and how long

before gas supply can berestarted

Will the gas supplyshutdown exceed 24 hours

duration ?

S/D Birba/Barik gas jnjectionand all gaslift consumption

from the SOGL

If isolation is upstream ofHubara, change Rima &

Hubara Power House over toDiesel fuel.

Optimise Marmul gas grid tosupply 2 (or 1) Marmul Powerturbines, change others over

to diesel.Utilise Al Noor gas to feedNimr and Haima West PS

Is the isolated section of lineupstream of Sahma ?

Request North Oman tosupply as much power asavailable, and shutdown

Rima turbine(s) if possible.

Send multi-disciplinemaintenance crews to

Booster stations initiatediesel changeover

In both Booster stationschangeover dual fuel turbines

to diesel fuel.

Is the isolated sectionof line between Sahma

and Hubara?

Maximise export of gas fromsuppliers downstream of the

SOGL isolation point

The isolated section of line isdownstream of Hubara so

operate both Booster stationsnormally

Run 4 pumps on diesel inHubara and 5 on SOGL gas in

Sahma

Calculate diesel requirementand advise UIE/3. Prepare off-loading facilities for sustained

operation, lights etc.

Maintain pressurebalance, of gas line prioritisingconsumers as per the list on

page 10

SOGL system failureresulting in loss of SOGL Gasto some or all gas consumes

NoYes

Yes

Yes

In the affected BoosterStations, shutdown the gas

driven booster pumps

No

BRP not applicable follownormal operating procedure

1

6

7

8

19

1817

14

16

15

1213

1011

4

2

9

No

If isolation is upstream ofSahma, SWT and Hubara

Power Houses will beshutdown

5

3

Establish which consumerswill be affected and how long

before gas supply can berestarted

Will the gas supplyshutdown exceed 24 hours

duration ?

S/D Birba/Barik gas jnjectionand all gaslift consumption

from the SOGL

If isolation is upstream ofHubara, change Rima &

Hubara Power House over toDiesel fuel.

Optimise Marmul gas grid tosupply 2 (or 1) Marmul Powerturbines, change others over

to diesel.Utilise Al Noor gas to feedNimr and Haima West PS

Is the isolated section of lineupstream of Sahma ?

Request North Oman tosupply as much power asavailable, and shutdown

Rima turbine(s) if possible.

Send multi-disciplinemaintenance crews to

Booster stations initiatediesel changeover

In both Booster stationschangeover dual fuel turbines

to diesel fuel.

Is the isolated sectionof line between Sahma

and Hubara?

Maximise export of gas fromsuppliers downstream of the

SOGL isolation point

The isolated section of line isdownstream of Hubara so

operate both Booster stationsnormally

Run 4 pumps on diesel inHubara and 5 on SOGL gas in

Sahma

Calculate diesel requirementand advise UIE/3. Prepare off-loading facilities for sustained

operation, lights etc.

Maintain pressurebalance, of gas line prioritisingconsumers as per the list on

page 10

SOGL system failureresulting in loss of SOGL Gasto some or all gas consumes

NoYes

Yes

Yes

In the affected BoosterStations, shutdown the gas

driven booster pumps

No

BRP not applicable follownormal operating procedure

1

6

7

8

19

1817

14

16

15

1213

1011

4

2

9

No

If isolation is upstream ofSahma, SWT and Hubara

Power Houses will beshutdown

5


Flowchart Notes for Gas Failure

The numbers preceding each note below, refer to the numbers on each box of the Flowchart on the previous page.

1. After an emergency involving the SOGL system, when the line is isolated and gas pressure is dropping, gas must be conserved.

2. Discuss with involved parties to establish facilities involved and time implications.

3. Establish that the situation meets the minimum criteria for a BRP; in this case at least one day to restore and normalise the SOGL gas supply.

4. If the severity of the incident is unlikely to meet BRP criteria, follow the normal operating procedure. The Area Coordinator has the final decision on the procedure to be followed.

5. If the isolation point on the SOGL is upstream of Sahma, Suwaihat Power House and Nimr Power House will have to shutdown as there is no alternative fuel to back-up.

6. If the isolation point on the SOGL is upstream of Hubara, Rima Power House will have to shut-down or change to diesel fuel. Initially the change over to diesel should be made until the full power availability can be established.

7. In any isolation of the SOGL, Marmul will be affected. Initially optimise the Marmul gas grid by increasing the export from the field compressors. Normally sufficient gas to run two power turbines on part load will be available. The third turbine (and possibly second if insufficient Marmul gas is available) should be changed over to diesel fuel.

8. North Oman Utilities should be requested to provide as much power via the inter-connector as possible. If there is sufficient power available, then Rima turbines should be shut down to conserve the diesel stocks as delivery of diesel to Rima is more difficult than to Marmul. It may be required to run one of the Rima turbines on diesel on part load to maintain the voltage above the critical point.

9. There should be an agreement in place that on loss of the SOGL, the Barik/Birba gas injection and all lift gas offtakes downstream of the isolation point be immediately closed in.

10. For the Booster stations, either Hubara alone or both Sahma and Hubara may be affected by the SOGL failure. As they both consume high volumes of gas, the affected stations should be isolated from the SOGL as soon as possible without causing any unnecessary deferment. The Marmul CCR should Coordinate the shut-down of the pump turbines that are unable to run on diesel.

11/12. Following on from above, the dual fuel turbines should be changed over to diesel fuel.

13. Change over to running on diesel fuel usually causes problems, so a multi-discipline team of maintenance technicians should be despatched to the relevant Booster stations. However, the change over by the Station Operator should not be delayed waiting for the arrival of the Maintenance Crew.

14. The Utilities Supervisor and the Operations Supervisor should calculate at the earliest possibility, the volumes of diesel likely to be required, and inform the Regional Head of Supply. These figures will be updated regularly as requirements change, the Supply Section should be kept informed.

15/16. If the isolation on the SOGL is between Sahma and Hubara, the four pumps in Hubara able to run on diesel, should be switched over. To balance this pumping capacity, five pumps should be run in Sahma on the SOGL gas.

17. If the isolation on the SOGL is downstream of both Booster Stations, they can both be run as normal using the SOGL gas as fuel.

18. Depending on the location of the point of isolation of the SOGL, the available gas exporters should be optimised to maintain the pressure in the gas line. If the isolation is downstream of the Central Oman gas exporters, Zauliyah should be used to maintain the critical requirements further South.

19. To obtain and maintain pressure stabilisation of the gas line, consumption should not exceed export into the line. Consumption should be maintained in order of criticality, as per the table in section 5.2 to the limit of available gas. It is acceptable to drop the line pressure gradually, by consuming the (considerable) line pack, as the most critical users do not require high pressure.



Appendix A: Glossary Of Terms, Definitions & Abbreviations

EmergencyA critical condition that may endanger Life, the Environment, Company Assets or Reputation and requiring intervention to minimise the loss.

Emergency Procedures A set of manuals developed to implement PDO's Emergency Procedures Policy and Objectives.

Contingency Plans Part III of the Emergency Procedures defining the strategy and operational plan devised for each conceivable emergency scenario.

Standing Instructions Departmental instructions identifying the responsibilities of the individual for operational activities.

Key Emergency PersonnelDesignate and alternate Competent Senior Staff responsible for manning the emergency control centres and taking key-roles in the Emergency Response structure.

Emergency Control Centre Dedicated location equipped with the necessary telecommunication equipment for the purpose of directing the emergency operation.

Local Emergency Base Controller A competent staff member responsible to coordinate Minor Emergency and Major Emergency response.

Stand down Demobilisation of personnel and resources required during the emergency

Operations Standard (OP) A series of controlled books containing standard operational procedures, policies and standing instructions.

Threshold Limit Value (TLV)The maximum concentration of a substance that an average worker can be exposed to for 8 hours a day during a 40 hour week, without suffering ill effects.

Lower Explosive Limit (LEL) The lowest concentration of an inflammable gas in air that will ignite under ideal conditions.

Abbreviations

BA Breathing ApparatusBRP Business Resumption PlanBVS Block Valve StationCCR Central Control RoomCECC Corporate Emergency Coordination CentreCRO Control Room OperatorDD Duty DirectorDEP Design and Engineering PracticesERD Engineering Reference DocumentsERP Emergency Response PlanESD Emergency Shut DownGGS Government Gas SystemLEBC Local Emergency Base ControllerLECC Local Emergency Control CentreLEL Lower Explosive LimitMaF Mina al FahalM of H Ministry of HousingMM Muscat MunicipalityMOL Main Oil LineMOG Ministry of Oil and GasMECA Ministry of Environment and Climate AffairsOSD South Oil DirectorateOND North Oil DirectorateOP Operations Standard



OSC On Scene CommanderOXE/3X Area Construction Superintendent Engineering ServicesPPE Personal Protective EquipmentPRA Pressure Reduction AreaRAFO Royal Air-Force of OmanROP Royal Oman PoliceROW Right of Way (Road along the Main Oil Line)S/D Shut DownSI Standing InstructionSOGL South Oman Gas LineUICUIC/4

Corporate Emergency Response & Security ManagerCorporate Emergency Management Coordinator (CFDH)

UIPT Pipeline Infrastructure and Oil Terminal ManagerUIPT/3 Terminal, MOL & SOGL Delivery Team LeaderUIPT/32 Pipeline System Management CoordinatorUIPT/2 Head Pipeline ProjectsUIPT/6 Head Pipeline IntegrityUIPT/4 Pipeline Maintenance Services



Appendix B: Telephone ContactsPDO Telephone Numbers

Name/job Title Ref. Ind. Office GSMPipeline Infrast & Oil Terminal Manager UIPT 24677267 92821225Corporate Security & Emergency Manager UIC 24670011 99311286Emergency Management Coordinator UIC/4 24673968 95521695Head of Pipeline Engineering Projects / CFDH UIPT/2 24677689 97292222Terminal, MOL & SOGL Delivery Team Leader UIPT/3 24675016 99661560Head of Pipeline Maintenance UIPT/4 24674828 99361755Head of Pipeline Integrity UIPT/6 24673221 97315007Head of Construction Services ONET/2F

ONET/2QOSE/3BOSE/3NOSE/3M

24383667 (Fahud)24385458 (Q.Alam)24388800 (Bahja)24382831 (Nimr)24386697 (Marmul)

Head Supply Logistics (Coast) UWL 24678431

Head Corporate Environmental (CFDH) MSE/2 24677309

PDO Specialist Resources:

Service Ref. Ind. PhonePDO Security UIC/X (on duty) 99472041Human Resources, Police Liaison EAC/21 (North)

EAC/22 (South)2438421924386257

Medical Officer MCO/1NMCO/1S

2438424524386439

Environmental Affairs MSE/2 (MAF) 24677309Environmental Advisor MSE/21

MSE/242467706124675167

Head Logistics UWLO (Coast)UWLN (North)UWLS (South)

246759522438495824382526

Supply Operations Cargo Haulage UWLO/1 (Coast)UWLN/1 (North)UWLS/1 (South)

24678865 2438425324382629

Supply Operations Warehousing / Materials UWLO/2 (Coast)UWLN/2 (North)UWLS/2 (South)

246777322438439224382124

Supply Operations, Transport (Air/Land) UWLO/3 (Coast)UWLN/3 (North)UWLS/3 (South)

246750942438442624386642

For Coastal Supply Operations, the duty person can be contacted on pager no. 99471825

99471825

Head Construction / Earthmoving Services ONET/2F (Fahud)ONET/2Q (Q.Alam)OSE/3B (Bahja)OSE/3N (Nimr)OSE/3M (Marmul)

2438366724385458243888002438283124386697

Pipeline Maintenance UIPT/45N (Fahud)UIPT/45M (Marmul)UIPT/45Q (Q.Alam)

2438370224386284/ 651224385844

Pipeline Materials and Corrosion UEOC/311 24676227



Government Telephone Numbers Ministries

Ministry of Oil and GasSwitchboard 24640555 / 24640556Facsimile 246691046H.E The Minister's Office 24640500H.E The Under Secretary, 24640666 / 24603490

Ministry of Regional Municipalities, Environment & Water ResourcesMunicipalities Switch board 24692550Facsimile 24753027Water ResourcesD.G. of Water Resources 246111222Ministry of Environment & Climate Affairs D.G. of Env. Affairs 24404814 Office(Mohammed Abdullah Al-Moharami)Switch board 24404500Facsimile 24692462Director of H.E. The Minister's Office 24602072

Muscat MunicipalitySwitch board 24753000Facsimile 24753027Office of the President 24706653 Deputy Chairman 24796033

Public Organisation For Electricity & Water

Switch board 24611100Facsimile 24699183D.G. Electrical 24661110Facsimile 24605367D.G. Water 24697386Facsimile 24607076

Police: full details can be obtained via UIC/42

Oil and Gas Installation Operations Manager 99034444 (Col. Salim Jabri)Police Head Quarters 24560021 Fax: 24560107

Muscat AreaWatayah Police Station 24677990

Matrah 24712211/24712212

Ruwi 24701099/24705754

AlAmrat 24875999/24876999

Boushar 24600099/24691199



Quriat 24845555/24845325

AlSeeb 24420099/24420200

AlBatinah RegionSuhar police Station 26840099/26840096

Barka 26882099/26882543

Al Dhahira RegionIbri Police Station 25689099/25689218

Fahud 24384222

Lekhwair 24381837

Yibal 24381202

Interior RegionNizwa Police station 25425559/25425222

Sumayil 25350099/2350213

Bid Bid 25360099

Izki 25340099/25342099

Nahada 24384495

Al Wosta RegionHaima Police Station 23436211

Qarn Alam 24385559/24385400

Rima 24382272

Nimr 24382391/23382392

Bahja 24388984/24388831

Hubara 24388564

Al Jazer 99238814

Al Duqum 25427088 / 25427188

Dhofar RegionMarmul 24386222

Shaleem 23200399

Thamreet 23279499/23277099



Appendix C: List Of Approved Contractors For Pipeline Emergency Repair

Pipeline Maintenance Contractors:

Name of the Contractor Area Covered Name of Contact Person Designation Tel. # Fax # GSM #Al-Ghalbi International Eng. & Cont. L.L.C North Oman, MAF &

FahudMr Fahim/Mr Osmani Site Manager 24385298 24385299 98081005

Al-Ghalbi International Eng. & Cont. L.L.C Qarn Alam Usman Site Manager 24388341 24388340 98081063

Amal Petroleum Services Marmul/ Nimr/ Rima/ Harweel/Bahja

Mr BalaMr Shajahaan

Site ManagerSr Pipeline Engineer

2438627824386203

24386232 9414724094105475

North EMC/ ODC:

Name of the Contractor Area Covered Name of Contact Person Designation Tel. # Fax # GSM #STST MaF (EMC) Vetrivel Planning Engineer 24567924 Ext13 24567923 95753853

STST Qarn Alam (EMC) Shyne Planning Engineer 24385830 Ext 201 24385829 96725751

Galfar Engineering All North (ODC) Ali Mopen Contract holder 24525353 - 99363077

South EMC/ ODC:

Name of the Contractor Area Covered Name of Contact Person Designation Tel. # Fax # GSM #Wood Group Marmul (EMC) Raid Site Coordinator - - 94106701

WPAI (on call basis – no contract) Marmul Samkumar Sr Project Manager - - 95310084

Wood Group Bahja (EMC) Raid Site Coordinator - - 94106701

ATE All South (ODC) Raghavan Contract Holder 24621200 Ext 294 24590212 99421565

ATE Bahja (ODC) Steven Site Manager 99285465 Ext 2501 - 99877451

ATE Marmul (ODC) Roy Dsouza Site manager - - 99246472

ATE NIMR (ODC) John D’Souza Site Manager - - 99863288



Appendix D: Change Control FormAny user of this 'Emergency Procedure', wishing to make a change or correction, is to use the 'Change Proposal' form and forward this to the document Custodian (UIPT/3), so that appropriate action can be taken.

Change Proposal Form CP No :

(By Custodian)

From :

To :

Purpose of Revision : Update Existing Data

Delete Obsolete Data

Insert New Data

Other

Proposed Change :

Continue on other sheet if necessary Signed, Originator

Approved for immediate implementation*

Approved for implementation at next revision*

Rejected for the following reason:*

* Delete as Appropriate Signed, Document Holder

Implemented

Signed, Document Custodian
