1-CF0000-40-PHL-0003-00

ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

COMPANY PROJECT No: 4700021770

CONTRACTOR PROJECT No: 67-00106

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

COMPANY DOC No: 1-CF0000-40-PHL-0003-00

Rev. 03

ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Contractor Document Number: CF0000-1085002

15/04/2024

18/12/2023

13/10/2023

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This Document is intended for use by ADNOC and its nominated Consultants, Contractors, Manufacturers and Suppliers.

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ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

COMPANY PROJECT No: 4700021770

CONTRACTOR PROJECT No: 67-00106

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

This document is rolled over from PCSA document no. 1-CF0000-40-BOD-0003-00 Rev. 00

COMPANY DOC No: 1-CF0000-40-PHL-0003-00

Rev. 03

SUMMARY OF DOCUMENT REVISIONS

Rev

Date

(DD/MM/YYYY)

21/03/2023

25/02/2023

03/02/2023

Status

Status Description

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IFA

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ISSUED FOR COMPANY APPROVAL

ISSUED FOR COMPANY REVIEW

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ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

COMPANY PROJECT No: 4700021770

CONTRACTOR PROJECT No: 67-00106

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

COMPANY DOC No: 1-CF0000-40-PHL-0003-00

Rev. 03

HOLD

Section

Description

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COMPANY PROJECT No. 4700021770 CONTRACTOR PROJECT No: 67-00106 COMPANY DOCUMENT No. 1-CF0000-40-PHL-0003-00

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

TABLE OF CONTENTS

PROJECT OVERVIEW … 5

PURPOSE … 6

DEFINITIONS & ABBREVIATIONS … 6

REFERENCE DOCUMENTS … 7

SCOPE …10

MANAGEMENT AND CONTROL OF H2S …10

6.1

6.2

Principles of Inherent Safety …11

Hazard control, mitigation and recovery …11

ACCOMODATION FACITIES WITHIN SOUR FIELD …30

BARGE REQUIREMENT WORKING IN SOUR FIELD …30

APPENDICES …30

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H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

PROJECT OVERVIEW

1.1

EPC for HAIL & GHASHA Development Project

The Hail & Ghasha Development (HGD) Project is of strategic importance to the Emirate of Abu Dhabi. The Project will develop the untapped oil and gas reserves from the highly sour Hail and Ghasha fields. Production is targeted to start by Q4 2027 with sustainable production of 1 BSCFD of raw gas, and max production of 82.5 MBPD of Oil, 76.3 MSTBD of Condenstae, 9000 TPD of Sulphur and 5030 TPD of NGL. In addition, Project will capture 1.52 million tonnes of CO2 per year taking ADNOC’s committed investment for carbon capture capacity.

The Hail and Ghasha fields are situated offshore ABU DHABI about 140 kms away from ABU DHABI mainland in water depths varying from 0 to 15 meters.

The HGD Project comprises the following:

• Artificial Islands Construction;

• Offshore package – EPC 01: Offshore Drilling Centers (DCs), Subsea Pipelines, Umbilicals, Power Cable Connections, Seawater Intake Structure, Bridges, Risers, Flare Structure, facilities at Ghasha Offshore Processing Plant (“GOP”);

• Onshore package – EPC 02: Manayif Processing Plant, Manayif Utilities, Offsite

Pipelines & Tie-ins, Main Control and Other Buildings.

The HGD Project will be executed in a single phase approach. It will start production from three Drill Centers (Reeah, Jzool & Seebah) in Ghasha Field to GOP and from Gaff Island in Hail field to OPP. Remaining Drill Centres, gas injection, and other associated facilities will be developed in ‘future’ to sustain production from Hail & Ghasha fields.

Figure 1 - Hail & Ghasha Field

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PURPOSE

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

This document sets out the Design H2S Philosophy for the Hail and Ghasha Development Project, for Offshore facilities.

The high toxicity and potentially fatal consequences associated with the high concentration of H2S (up to 50% in specific process stream) in the process design dictates the reasons for a standalone H2S philosophy for this project.

The H2S philosophy aims to define the fundamental principles that are to be adopted with respect to eliminating / minimizing the risks associated to H2S in the design. This document represents the minimum requirements and shall be read and implemented in conjunction with project specifications, procedures and philosophies.

This document is intended to inform the PROJECT team of key requirements that need to be addressed so that the risk to people will be reduced to a level as low as reasonably practicable (ALARP).

This H2S Philosophy covers the PROJECT scope in relation to the Ghasha Offshore Processing Island (GOP), and Ghasha and Hail Drilling centers with regards to design and operations. Drilling Operations in regard to the Drilling Islands are outside the scope of this H2S Philosophy and fall under the Drilling Contractors scope.

This document should be kept live and updated throughout the project to capture further detail and refinements.

DEFINITIONS & ABBREVIATIONS

3.1

Definitions

COMPANY

Abu Dhabi National Oil Company (ADNOC)

CONTRACTOR

Integrated JV (NPCC -SAIPEM)

PROJECT

Hail and Ghasha Development Project

OFFSHORE PROJECT

Hail and Ghasha Development Project – Package 1: Offshore Facilities

3.2

Abbreviations

ADNOC

Abu Dhabi National Oil Company

AEGL

AGES

ALARP

BSCFD

EAD

EAZ

Acute Exposure Level Guidelines

ADNOC Group Engineering Standards and Specifications

As Low as Reasonably Practicable

Billion Standard Cubic Feet per Day

Drilling Centre

Environmental Agency, Abu Dhabi

Emergency Awareness Zone

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EERA

EEBA

EPC

EPZ

FERA

GOP

HAZID

HAZOP

HGD

HSE

Emergency Depressurisation

Emergency Escape Breathing Apparatus

Engineering, Procurement and Construction

Emergency Planning Zone

Fire & Explosion Risk Assessment

Ghasha Offshore Processing

Hazard Identification (Study)

Hazard Operability

Hail & Ghasha Development

Health Safety and Environment

HSECES

HSE Critical Elements and Systems

HSEIA

HSEMS

H2S

ISD

LSIR

MAH

Health Safety and Environmental Impact Assessment

HSE Management System

Hydrogen Sulfide

Inherent Safe Design

Location specific iso-risk

Major Accident Hazard

MMSCFD

Million Standard Cubic Feet per Day

MSBPD

Thousand Standard Barrels per Day

NGL

OPP

PPE

Natural Gas Liquids

Onshore Processing Plant

Personal Protective Equipment

SIMOPS

Simultaneous Operations

SCBA

Self-Contained Breathing Apparatus

TGR

TOP

TPD

UAE

UPS

Toxic Gas Refuge

Temporary Refuge

Top of Pipe

Tonn per Day

United Arab Emirates

Uninterruptable Power Supply

REFERENCE DOCUMENTS

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Sl. No.

Document Title

Abu Dhabi Law No. 1 of 1988 establishing the Supreme Petroleum

Council Abu Dhabi Emirate Law No. 21 year 2005, “Waste Management in Emirate of Abu Dhabi” Abu Dhabi Emirate Law No. 8, year 1978, “Conservation of Petroleum Resources”;

UAE Federal Law No. 8, year 1980, Regulations of Labor Relations
Ministry of Labor and Social Affairs, Ministerial Order No. 32, year to Protect

the Ways and Means

1982, “Determination of Employees against Occupational Hazards” UAE Federal Law No. 24, year 1999, “Protection and Development the Environment” and Regulations developed by Federal of Environment Authority based on the Executive Act of Federal Law No. 24, year 1999 “Protection and Development of the Environment” Cabinet Decree No (12) of the year 2006 concerning the Protection of Air From Pollution

UAE Fire & Life Safety Code, September 2018

Public Health England (HSE UK) - Compendium of Chemical Hazards: Hydrogen Sulphide (report 2014790)

HSE-GA-ST07 - HSE Design Philosophy

HSE-OS-ST08 - Confined Space Standard

HSE-OS-ST20 - Personal Protective Equipment Standard

HSE-OS-ST21 - Management of Hydrogen Sulphide

HSE-OS-ST27 - Hazard Communication Standard

HSE-OS-ST29 - HSECES Management Standard

HSE-RM-ST01 - HSE Risk Management Standard

HSE-RM-ST06 - Control of Major Accidents Hazards (COMAH) Standard

HSE-RM-ST07 - Escape Evacuation & Rescue Assessment (EERA)

HSE-RM-ST08 - Emergency System Survivability Assessment (ESSA)

HSE-RM-ST09 - Fire Safety Assessment (FERA)

HSE-RM-ST10 - Quantitative Risk Assessment (QRA)

HSE-GA-ST01 - HSE Governance Framework

HSE-GA-ST06 - Project HSE Plan

HSE-EN-ST01 - Environmental Impact Assessment

HSE-EN-ST07 - Air Dispersion Modelling Techniques (TBC)

AGES-GL-03-001 - Facility Layout and Separation Distances Guidelines

AGES-PH-03-001 - Emergency Shutdown and Depressurisation System Philosophy

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Document Title

AGES-PH-03-002 - Fire & Gas Detection and Fire Protection System Philosophy

AGES-SP-03-001 - Escape, Evacuation, Rescue & Life Saving Appliances (EER & LSA) Specification

AGES-SP-03-003 - Building Safety Specification

1-CF0000-52-PLN-5801 - Project HSE Plan

1-CF0000-40-PHL-0002 - HSE Design Philosophy

1-CF0000-40-BOD-0004 - Fire Protection Design Basis

1-CF0000-40-PHL-0005 - F&G Detection Philosophy

1-CF0000-40-PHL-0006 - EERA Philosophy

1-CF0000-59-PHL-0001 - Basic Engineering Design Data (BEDD)

1-CF0000-04-PHL-0006 - Flare Blowdown Philosophy

1-SB0000-34-BOD-0400 - Offshore Pipelines, Risers and Umbilicals Basis of Design

1-CA0000-16-SPE-1050 - Building Fire Alarm System Specification

TENE-HGDP-59-DCA-0026_A - GOP HP Flare Stack Height

1-CF0000-01-SPE-1016-00 - Architectural Design Basis

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SCOPE

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

The ADNOC HSE Policy states that ADNOC and it Group Companies are committed to: “pursue no harm to people, which includes community, and to protect the environment” The Policy further states that: Further as per Project HSE Plan (1-CF0000-52-PLN-5801) Safety Objective is to Provide a safe design and working environment for personnel. Facilities layout & design to ensure inherent safety and reduce risk to personnel and assets to As Low As Reasonably Practicable (ALARP) levels. This philosophy is developed to provide a baseline rule to manage and control H2S risk. This includes applying: • Design for normally unmanned facilities for the gathering systems and export facilities;

• Elimination, and substitution of the H2S risk where practicable such as lowering the operating pressure (hence lowering H2S partial pressure), and elimination of the SIMOPs requirements where possible.

• Engineering to control the H2S hazard.

• Separation distance for SIMOPS cases and also to third party and public areas. This is

presented in the form of toxic separation distance Risk Tolerability Criteria.

• Organizational and procedural controls such as imposing Red, Amber and Yellow

zones access and work controls, and Escape and Evacuation requirements.

• Personal Monitoring and Respiratory Protective Equipment requirements and adequate

provisions for means of escape.

MANAGEMENT AND CONTROL OF H2S

As per ADNOC HSE-GA-ST07, the approach towards hazard management of the facilities design shall consider the following in the order of priority.

• Prevention/Elimination – Measures taken to eliminate or reduce hazards at source or

to reduce the likelihood of a hazard being realised.

• Control – Measures taken to keep hazards within the design envelope, be it through containment or control systems or reactions to events that could result in an incident.

• Mitigation – Measures taken to respond to a hazard once an incident has occurred

either to bring it back under control or limit its effects.

• Recovery – Measures taken to recover from a hazardous event using appropriate

response and recovery measures i.e., ERP, usage of PPE’s etc.,

The design shall include the principles of Inherently Safe Design. However, should hazardous events occur, they should be promptly detected and acted upon, with the aim of reducing the risk to personnel and the environment and minimizing the damage to equipment, plant and structures. The evaluation of the required control and mitigation measures will be based mainly upon the extent of consequential effects of an accidental event and adopting a risk-based approach.

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6.1

Principles of Inherent Safety

The facilities on the ADNOC Hail and Ghasha Development shall be designed such that they are, as far as reasonably practicable, inherently safe, i.e. the hazards have been designed out or that their consequences are no longer a threat to personnel or the environment.

An inherently safe design is one where the hazards have been eliminated and the likelihood and severity of potential accident events have been minimised as far as is reasonably practicable.

A EPC Inherent Safety in Design (ISD) Workshop, Hazard Identification (HAZID) and Hazard Operability Study (HAZOP) shall be performed to identify the Major Accident Hazards (MAHs), evaluate the risk and analyse any risk reduction measures.

To achieve the above said objectives, four primary strategies in line with ADNOC HSE standard, HSE-RM-ST13 will be followed as below:

•

Intensification: Try and minimise the quantities of hazardous substances.

• Substitution: Try and replace each hazardous material with a less hazardous

alternative.

• Attenuation: Using less hazardous conditions, especially avoiding any conditions under which materials become more hazardous (e.g. do not process materials above their auto-ignition temperature.)

• Limitations of Effects: Design facilities that minimise the impact of a release of hazardous material or energy e.g. by providing separation between plants, storage areas, process trains and minimising manning in hazardous areas.

• Simplification: Design facilities that make operating errors less likely and the operation intuitive. It should be easy to do the right thing and difficult to do the wrong thing.

• Error Tolerance: Design the facilities so that even if someone does the wrong thing, a

hazard will not result.

6.2

Hazard control, mitigation and recovery

The hierarchy of control principles as shown in Figure 2 forms the base line of the H2S toxic risk management and control strategy for Hail & Ghasha. The following sections highlight the H2S risk management strategy to be adopted for the Hail and Ghasha project in reducing the H2S toxic risk to a level which can enable demonstration of ALARP.

Figure 7.1: Hierarchy of Control for Risk Reduction

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Figure 2 – Hierarchy of control

As it may not always be possible to totally eliminate hazardous occurrences (H2S Releases etc), specific measures shall be implemented to control and mitigate the extent of the event and to provide the means to recover from the event.

The following measures will be included in the design to control, mitigate, and recover from hazardous events:

• Minimise leak paths (e.g. reduce flanges, reduce small bore piping, use of high integrity

equipment etc.)

• Selection of Fail-safe equipment

• Fire and gas detection system to detect a fire or a flammable / toxic gas leak.

• Emergency shutdown systems to isolate the plant.

• Emergency depressurisation systems

• Layout optimisation to reduce the size of any resultant explosions, toxic release and

potential escalation.

• Active Fire Protection (AFP) to control and/or extinguish the fire.

• Passive Fire Protection (PFP) to protec against heat from a fire without additional

intervention (and therefore to prevent escalation),

• Emergency power via Uninterruptible Power Supply (UPS) to preserve the ability to

monitor and control an accident.

• Suitable and reliable general alarm system to warn personnel of any incident so that

they can take appropriate action.

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• Adequate access for rescue of injured persons, emergency evacuation, and

maintenance.

• Adequate escape routes to a safe muster area.

• Muster facilities which are sufficiently protected from process and wellhead areas.

• Evacuation facilities which are appropriately sized for the expected manning levels.

• Provisions of dual control valves

• Design to avoid use of pumps using pressure driven liquid transfer

• Use of high reliability instrumentation or redundant instrument where a single traditional

instrument would be provided along with a level gauge or sight glass

• Avoidance of screw fittings in high H2S areas.

In addition to the measures intended to prevent, control and mitigate hazards, the following measures shall be provided to aid recovery from incidents:

• A Temporary Refuge/Toxic Gas Refuge (TR/TGR) where personnel can survive,

monitor and respond to an incident or emergency response;

• Provision for diverse, redundant egress routes and their survivability in the event of an incident from all working areas to the muster area (within the TR); where applicable consideration should be given to a secondary means of evacuation / muster area.

• TEMPSC and life-saving appliances according to AGES-SP-03-001, the International Convention for the Safety of Life at Sea (SOLAS) guidelines and the Escape, Evacuation and Rescue Assessment (EERA) results;

• Helipad provided on the Drilling Centres, GOP and Gas Injection Wellhead Platform

(FUTURE FACILITY, NOT IN SCOPE) to evacuate injured personnel

All the above measure will be detailed in the Project Emergency Response Plan for operations based on ERP strategy in line with ADNOC requirements.

• Maintenance/Operation activities will be defined based on Technical Integrity and

Operating integrity requirements

6.2.1

H2S Toxic Effect on Personnel

The harmful effect of H2S on humans is dependent on the toxic load to which the individual is exposed. As per ADNOC HSE-OS-ST21, Toxic load is calculated as a cumulative sum of concentration over time;

Where;

• TL is the Toxic Load

𝑛𝑛

𝑇𝑇𝑇𝑇 = ∫ 𝐶𝐶

𝑑𝑑𝑑𝑑

Equation 1

• C is the concentration of H2S (measured in ppmv, but sometimes expressed in mg/m3)

•

t is the duration of exposure (in minutes) to that concentration

• and n is an exponent that is used to indicate the non-linearity of the dose to concentration with time. A number of values have been proposed for n for H2S by

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regulatory and professional bodies, but it is commonly accepted that n is approximately 4.

•

If an individual is exposed to a constant concentration over time, then equation 1 can be simplified to

Equation 2

𝑛𝑛

𝑑𝑑

𝑇𝑇𝑇𝑇 = 𝐶𝐶

Therefore, both concentration and exposure time need to be considered when assessing harmful impacts to humans from H2S, but as the exponent, n, is bigger than 1, an increase in H2S concentration (e.g. doubling the concentration) has a more significant toxic load effect than an equivalent increase in duration (e.g. doubling the exposure time). This is a key factor that must be considered in determining the H2S Risk Tolerability Criteria. As per ADNOC HSE-OS-ST21, Probit based on UK HSE to be used for risk assessment.

6.2.1.1

Effect at Low H2S Concentrations

At low H2S concentrations, the gas has an irritating effect on the eyes and membranes of the nose, throat, and lungs. H2S can be detected by smell in the parts-per-billion range, and at 0.1 parts per million has a pungent, unpleasant odour of rotten eggs. At this concentration, it is not harmful to health.

Low concentrations below 1 ppmv generally define the Occupational Exposure Limits (OELs).

Concentrations of significance at these levels are:

• Threshold limit value (TLV) for Time Weighted Average (TWA) for safe, continuous exposure during the average work regime of 8 hours a day, 5 days a week, is defined as 1 ppmv by ACGIH.

• The Short-Term Exposure Limit (STEL) for H2S, which allows for safe exposure for

fifteen minutes at a time, has been changed to 5 ppmv by ACGIH.

However, it shall be noted that the TLW-TWA provided by HSE UK (ref. 9) as well as by ADNOC standard HSE-OS-ST21 (ref. 11) are:

• TLV-TWA (8 hour): 5ppm

• TLV-STEL (15min): 10ppm

6.2.1.2

Effects at High H2S Concentrations

H2S is highly toxic at higher concentrations as it is absorbed rapidly in the bloodstream, interferes with cellular respiration and on inhalation, it can have effects on brain function.

At higher concentrations, H2S starts to affect the central nervous system and can cause the accumulation of fluid in the lungs (pulmonary edema).

At 50-150ppmv H2S can start to knock out the sense of smell and this is one of the dangers of the gas; operators cannot rely on the sense of smell. At higher concentration levels this happens immediately and H2S cannot be smelt at all.

The following summarizes the effects of H2S at high concentrations as reported by the HSE UK (ref. 9) and as well as the HSE-OS-ST21 (ref. 11);

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• 27 ppmv is the AEGL 2 for 60 minutes exposure is defined as the limit associated with “disabling” effects from H2S exposure. It is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed, in an emergency, for up to 1 hr without experiencing or developing irreversible or other serious health effects or symptoms.

• 76ppmv is the AEGL 3 for 10 mins exposure. It is defined (ref. 9) as the airborne concentration of a substance above which it is predicted that the general population, including susceptible individuals, could experience life-threatening health effects or death.

This is defined by ADNOC HSE-OS-ST21 (ref. ref. 11) as the limit for Emergency Protection Zone (EPZ). Within this distance only trained operators carrying the appropriate safety equipment should be allowed to operate and work. A suitable emergency response plan should be in place to evacuate the workers within this distance to a safe location if there is a release of H2S

• 100ppmv for 30 minutes exposure is a different level defined by a separate organization. By definition it is similar to the AEGL 3 level, but obviously it is less conservative because it corresponds to a longer exposure time. It is included in this philosophy because it is defined by HSE UK (ref. 9) as well as by National Institute for Occupational Safety and Health as ERPG 3 (Emergency Response Planning Guidelines) that means the concentration at which appropriate emergency response should be taken.. This value is also specified to determine Yellow Zone extent as toxic end point for reasonably worst case scenario (25mm) as per ADNOC HSE Standard HSE-OS-ST21.

• 300ppmv is generally regarded as the level at which short term exposure to H2S switches from causing transient effects to potentially causing irreversible health effects.

• 650ppmv is defined to be the concentration at which 1% of the exposed population will suffer fatality (or incapacitation leading to a fatality) if they are exposed to H2S for less than 10 minutes as per the SLOT-DTL LC1 (1% Lethal Concentration). This means that exposure to 650ppmv, in an emergency, could be tolerated for a very short duration e.g. 75 seconds where EEBA/SCBA should be donned quickly.

• Above 1000ppmv the effects of H2S can be instantaneous; immediate knock-down.

Rapid rescue and resuscitation are the only chance of survival.

6.2.2

H2S ZONE CLASSIFICATION

H2S zone classification enables some level of control over individual exposure to high risk process areas and also includes applying protection measure such as Respiratory Protection Equipment (RPE) in areas where H2S risk is deemed highest. For consistency, the H2S risk areas are referred to as either Red, Amber, and Yellow zones.

ADNOC HSE-OS-ST21 requires ADNOC Group Companies to classify areas on their plants that handle hydrogen sulphide according to the level of risk and specifies the access controls and precautions to be adopted when entering classified areas. The HSE-OS-ST21 specifies three risk zones:

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• Red Zone

o Where the toxic risk (Toxic - LSIR) is greater than or equal to 10-3 per year o Locations such as confined spaces, valve pits with high H2S containing

equipment, etc. where free movement is highly restricted

• Amber Zone

o Where the toxic risk (Toxic - LSIR) is greater than or equal to 10-4 per year o Toxic end point of 700 ppm from reasonably worst-case scenarios for each leak sources. Reference shall be made to ADNOC standard on HSE risk management for selection of reasonably worse case representative release sizes

o Locations which contain sour gas (1000 ppm) containing equipment in very high congestions / obstruction regions (typically Volume Blockage Ratio (VBR) greater than 50% or typical highly congested offshore module) and Air Changes Rate (ACR) of 12 can’t be maintained for 95% or more and free movement of personnel and escape / evacuation is restricted. Typical examples are highly congested offshore processing platforms.

• Yellow Zone

o Where the toxic risk (Toxic - LSIR) is greater than or equal to 10-5 per year o Toxic end point of 100 ppm for reasonably worst-case scenarios for each leak sources at a distance more than 2m. Reference shall be made to ADNOC standard on HSE risk management for selection of reasonably worse case representative release sizes.

6.2.2.1

Definition and Size of Red, Amber, Yellow Zones

The definition of hydrogen sulphide (H2S) zones is designed to ensure that safety measures taken provide a level of safety that can demonstrate ALARP.

The below classifications of zones represent a mandatory minimum requirement as outlined within ADNOC HSE-OS-ST21. Areas can be classified as Red, Amber, or Yellow even when they are technically a less hazardous zone, in order to simplify the application of controls and the usage of PPE.

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6.2.2.2

Risk Reduction Philosophy

During project life cycle, philosophy of risk reduction requires the following demonstration:

• Elimination of Red Zones as far as reasonably practicable or minimization of Red Zones

to absolute minimum

• Elimination / Reduction of personnel exposure to Red Zones as far as reasonably

practicable

• Reduction in the size of Amber and Yellow Zones

• Elimination as far as reasonably practicable or minimization of overlap of Red and Amber Zones in cases where maintenance is required on one unit, when the other unit is operational.

• Limiting the size of Yellow Zones within the facility boundary.

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•

If the Red, Amber and Yellow zones extend beyond the facility boundary, the risk is deemed unacceptable and further engineering risk reduction measures are required such as separation distances, Sectionalization, faster blowdown, automated shutdown and blowdown upon confirmed toxic gas detection, etc.. However, about the last two bullets above, it shall be considered that, in the offshore facilities, outside the facilities boundary the presence of non authorized and non trained people is not expected (i.e. over the sea).

During operations, the philosophy of risk reduction requires the following demonstration:

• Manual of Permitted Operations within Red and Amber Zones should be prepared;

• Demonstration of ALARP is required when simultaneous Activities will be undertaken within Red and Amber Zones. This will require developing risk assessments pertaining to the works that are going to be performed and

• Reducing or maintaining the initial estimates of Red, Amber, and Yellow Zones. This should consider the aging patterns of the facilities, especially when producing the updated HSEIAs.

6.2.2.3

Determination of Emergency Zones

As per ADNOC HSE-OS-ST21, for emergency planning, two zones are identified, as below;

Emergency Planning Zone (EPZ) corresponds to the zone where any member of the public, animal pens or non-essential personnel at large should be evacuated to a safe area prior to the start of the operations. Only operations related personnel (essential) can be present in the area. Working personnel from simultaneous operations in this zone shall be treated as operations workforce for the purpose of H2S training and emergency evacuation. This zone is outside the plant or industrial zone boundaries and could be exposed to a concentration corresponding to AEGL-3 (10 min) i.e., 76 ppm for H2S and 30 ppm for SO2 from reasonably worst-case (25mm) representative scenarios.

Emergency Awareness Zone (EAZ) corresponds to the zone where the public at large should be informed about the consequences of a toxic release (H2S or SO2). This zone goes beyond the EPZ to the extent where the H2S concentration will reach 10 ppm for H2S and 2 ppm for SO2 for reasonably worst-case (25mm) representative scenarios.

Members of the public shall be located beyond EAZ and Offsite Emergency Plan shall be rolled out prior to commissioning. Accommodation and canteens/ restaurants shall be located outside the EAZ. Where it is impracticable due to operational requirements and associated space constraints (such as Artificial Island, offshore complexes, etc.) to locate accommodation outside EAZ they shall be designed and demonstrated with TR/TGR capabilities for the duration of evacuation in line with the guidance given in HSE-OS-ST21 and ADNOC EERA Standard HSE-RM-ST08. For such cases, a detailed Emergency Evacuation Plan including evacuation means and provision shall be in place to demonstrate that personnel are able to muster in TR/TGR and evacuate the facility safely considering TR/TGR duration.

6.2.2.4

Working in Red, Amber, Yellow, and Green Zones

RED ZONES

All personnel entering a red zone shall have H2S training, competence and certification, carry a personal H2S monitor and don breathing apparatus, and use it at all times.

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As a minimum, the following shall be considered:

a) Access control shall be adhered to as mentioned in below Sec 6.2.2.5;

b) At all times SCBA set shall be donned and in use and for all prolonged work use

airline fed breathing apparatus shall be ensured;

c) Provide a means of constant communication (i.e. fixed plant telephone or hand held radio) with someone located outside the Red Zone, in addition to use of the buddy system;

d) Move any operator rooms/shelter, e.g. those for sour gas compressors, outside the

red zones, or make the operator room a temporary refuge;

e) Avoid as far as possible any work such as painting, or civil works maintenance until the process plant is depressurized. This is reasonably practical if the plant is designed for this approach, e.g. has good segregation distances and is designed for minimum onsite work;

f) Avoid as far as possible the need for routine work in the Red Zone for example use transmitters rather than gauges, and automatic sampling rather than manual sample taking; and

g) Operating companies shall review whether it is necessary to carry out the tasks in the Red Zone while the plant is operating. The work activities in the RED Zone shall be minimized to an absolute minimum as far as practicable.

AMBER ZONES

All personnel entering an Amber zone shall have H2S training, competence, and certification, shall wear a personal H2S monitor, and, as a minimum, shall carry an Emergency Escape Breathing Apparatus (EEBA) or have it at hand’s reach.

Those, involved in performing activities requiring the opening of process components that contain, or may contain H2S (intrusive work/breaking containment) shall have the breathing airline apparatus or SCBA set donned and in use;

As a minimum, the following shall be considered:

a) Access control shall be adhered to as mentioned in below Sec 7.2.2.5;

b) Provide a means of constant communication (i.e. fixed plant telephone or handheld radio) with someone located outside the Amber Zone, in addition to the use of the buddy system;

c) Moving any operator rooms/shelters, e.g. those for sour gas compressors, outside

the Amber zone, or making it a temporary refuge; and

d) Avoid as far as possible any work such as painting, civil works maintenance until the process plant is depressurized. This is reasonably practical if the plant is designed for this approach, e.g. has good segregation distances and is designed for minimum onsite work.

YELLOW ZONES

Anyone entering a Yellow Zone shall have H2S training, competence and certification as, be aware of the location of strategically placed EEBA sets, and shall wear H2S Monitor.

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While the risk of exposure to dangerous concentrations of H2S is much lower when working on equipment in the yellow zone, there can still be a significant risk of toxic injury and illness during some operations. Opening of H2S containing equipment shall only be undertaken by persons donning breathing airline apparatus or SCBA set and a portable H2S detector used for monitoring.

For sampling activity in H2S Zones, SCBA shall be worn and the area be cleared to a safe distance while opening and isolating and until the equipment is purged and while de- spading and restoring to service. The area shall be marked off and signed as for Red and Amber Zones during these activities. The size of the restricted area shall be determined during the Job Safety Assessment (JSA) based on dispersion analysis.

6.2.2.5

Access Control to H2S Classified Areas

Entry to H2S Zone areas shall be controlled and secured to prevent unauthorized persons from accidentally entering the area. Access to Zones shall be limited to personnel holding a valid certificate for H2S competence as per HSE-OS-ST21. A system should be in place for personnel to register in/out when entering or leaving Red Zones, or a wireless personnel tracking system used, so that it is possible to establish who is present in the event of an emergency.

Where registration of entry/exit to a Red Zone is not reasonably practicable, for example where entry into a Red Zone is by helicopter landing on a platform which is a Red Zone in entirety, then an alternative system may establish that fulfills the intent of the registration system: controlling entry to authorized persons only, determining who is present in the event of an emergency and ensuring PPE is provided.

6.2.3

H2S Design Practices

ADNOC HSE-OS-ST21 details three groups of design practices that can reduce the risk of personnel exposure to H2S.

Plant Layout Design to reduce risk from plant operability
Design measures to reduce risks of accidental releases
Design measures to reduce personnel exposure to releases
Design for sour service

6.2.3.1

Plant layout

Facilities with Yellow, Amber or Red Zones must be designed and laid out to:

• Minimise the size of Red Zones;

• Allow simple segregation of the site into Red, Amber, and Yellow Zones;

• Plants should be designed for minimum intervention requirements within the Red Zone(s), so that operator and maintenance team visits to the red zone are minimized;

• Plants shall be designed to facilitate breathing airline to ensure sufficient duration of air

supply for personnel working in the Red Zone;

• Plant layout should minimize the impact of H2S Zones on Construction activities

considering a Phased development plan.

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• As far as practicable working at height or on elevated platforms in the Red Zone must

be avoided by design.

• Avoid venting of fluid containing > 5ppm hydrogen sulphide direct to atmosphere for any reason. Such gases must be routed to a suitable acid gas recovery system or flare;

• Flares and associated sterile areas must be designed to avoid exposure of any person to hydrogen sulphide beyond 15-min STEL limits (i.e. 10 ppm) in the event of flameout. However, according to DCA issued by Re-FEED Contractor and Approved by Company (see TENE-HGDP-59-DCA-0026_A - GOP HP Flare Stack Height, ref. 34), it is acceptable to have an H2S concentration of 10ppm at ground level outside the sterile area in case of flame out, considering that GOP handles Sour Gas and the entire plant is provided with toxic gas detectors. In addition, personnel are provided with personnel toxic gas detectors and BA/EEBA sets. The same waive-off shall be applied also during EPC phase.

• Flares handling material containing hydrogen sulphide must be designed to avoid exposure of personnel to sulphur dioxide combustion products beyond the 15-min STEL limit.

• Avoid placing equipment in confined spaces, pits, or low-lying areas where hydrogen sulphide could build up and where entry may be required from time to time e.g. for maintenance, sampling etc. Where it is not reasonably practicable to avoid such arrangements, facilities must be provided to avoid the need for man entry into the confined space on a regular basis.

• Shall have a fixed hydrogen sulphide gas detection system.

• Demonstrate that the sectionalisation of plant by ESD valves and the time required for emergency blowdown of plant sections is such as to reduce risks to people to as low as reasonably practicable.

• Non process buildings with higher manning (e.g. workshops) should be located as far as practicable from red, amber, and yellow zones. The safety of such locations should be verified by calculation.

• Escape routes and temporary gas refuges must be selected for the possibility of rapid

and safe evacuation.

Access to elevated platform for columns, vents, etc. where the provision of staircase is not practical, access by vertical ladders may be provided. In such cases the vertical ladder shall be designed to allow safe and efficient escape donning SCBA / EEBA. In addition to the requirements stated in HSE-OS-ST21, the following shall be considered in the design of facilities in the RED and AMBER zone:

• Stairways in Red Zones shall be minimum clear width 1.5m.

• Use of Ladders shall not be permitted in Red Zones.

• Platforms in Red Zones shall provide minimum clear access width 1.2m.

• Manways in Red Zones shall be amended as follows:

 Process Vessels in Red Zones above 1500mm ID with dirty service shall have

30” manway size;

 Process Vessels in Red Zones Less than or equal to 1500mm ID with dirty

service shall have 24” manway size

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• Barrier fluid reservoirs in Red Zones shall have minimum 50 litres capacity.

• A barrier fluid filling system shall be provided for pumps in Red Zones.

• Sampling points in Red Zones shall be located at grade.

• Closed drain system shall be buried instead of routing through trenches to eliminate

H2S settlement except for sulphur drain.

• The carrier gases for the GCs are not monitored- PT to be installed to the cylinder rack and alarm sent back to DCS, this will save unnecessary man visits to the red zone

• The access way for the shelter/cabinet cylinder storage should be low enough that a trolley can be pulled up easily. Concrete plinth too much high causes difficulties in moving and storing cylinders.

• Suitable sunshade should be considered for air cons in cabinets.

• Shelters / Cabinets windows shall have suitable UV film to protect the displays from

direct sunlight.

• Air con units condenser and piping etc. should have increased protection with

necessary coating against H2S, SO2 vapours and “acid rain”.

• Breathing air network in the red zone shall be designed with accessible connection

points, hooked up BA sets including platforms and stair ways etc.,

• Where local chemical skids are installed in the Red Zone, the filling point shall be located outside the Red Zone with provisions for hook-up with portable transfer pump.

6.2.3.2

Prevention of Accidental Releases

The following are key in ensuring the risk of accidental releases are as low as reasonably practicable;

• Choice of Material

o Hydrogen sulphide is corrosive to steel, especially when present with free water. Stress corrosion cracking (SCC) occurs on passivated materials such as stainless steels subjected to tensile stress. Stress oriented hydrogen induced cracking (SOHIC) occurs where there is a high stress concentration in sour service equipment. These forms of failure can be prevented or reduced to low levels by proper selection of materials.

o Selection of metallic materials of construction shall conform to ISO 15156 or better. (If better, the improvement shall be documented by test results following ISO or NACE International standards).

o Pipeline carrying sour fluid are provided with CRA internal cladding as detailed in Offshore Pipelines, Risers and Umbilicals Basis of Design (1-SB0000-34-BOD- 0400)

o Design of the facilities to fit for sour service in line with ADNOC HSE standards

(500ppm)

• Selection Pipe Thickness

Increasing pipe wall thickness by selection of a higher schedule or class than that required for service is a standard risk reduction approach. Increasing thickness

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reduces stress, provides an increased corrosion allowance, and makes pipelines more robust against third party interference.

• Protection of Pipelines / Flowlines

o Third party interference is one of the major causes of pipeline failure. Risk to pipelines can be reduced by various techniques. Techniques used in Abu Dhabi are deep burial, use of designated and fenced rights of way or easements, use of mounding to signal pipe location and to discourage excavation and driving over pipes, and use of plastic marker strips at 30 cm above pipeline TOP.

o Burial versus sea bed placement; o Use of dropped object protection mats; o Providing exclusion zones at platform riser locations and in the areas near platforms, to reduce risk from dropped objects, anchor drag and trawling risks;

o Design to avoid bridging due to sea bed scouring and to limit current induced vibration fatigue; Use of subsea isolation valve which can close to shorten the duration of a leak.

o Use of dropped object protection mats should be considered for subsea pipelines

on a zone by zone basis, particularly in the zone near risers.

6.2.3.3

Control of Accidental Releases

There are a number of measures that can be applied to reduce the quantity of gas released following a loss of containment. The following measures are outlined in detail within ADNOC HSE-OS-ST21;

• Battery limit ESD Valves could be provided on main incoming lines, at the inlet to sour gas absorbers and in some cases at the inlet to SRU incinerators (to be decided by ALARP analysis). The objective is to prevent upstream units from “feeding the release”.

•

Inventory isolation valves can be fitted on the entry and exit lines of separators, columns, surge and feed vessels, and especially at amine regenerator overhead lines. These have the effect of limiting release via piping leaks and ruptures to the inventory of the piping itself.

• Fail-safe Down Hole Safety Valves (DHSV)/Sub-Surface Safety Valves (SSSV) shall be provided on all new wells where the well fluid contains more than 500 ppm H2S.

• High Capacity blowdown systems to flare may be provided so that small and medium- size releases can be depressurised quickly. Refer to Flare Blowdown Philosophy (1- CF0000-04-PHL-0006) for details.

• Sectionalisation ESD valves shall be provided as appropriate.

• Many of the accidents associated with Hydrogen Sulphide occur during maintenance when fitting or removing spades, or by inadequate isolation. Good isolation during maintenance is an essential measure for hydrogen sulphide release prevention.

Note: Planned venting of gas containing hydrogen sulphide is forbidden. Gas containing hydrogen sulphide must be routed to a suitable flare with a sufficiently high stack height to ensure that concentrations of SO2 and potentially un-burnt H2S at ground level cannot exceed the STEL, taking into account downwash due to unstable atmospheric conditions and to buildings, tanks and process equipment.

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6.2.4

H2S Detection

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For a detailed overview of the type and functionality requirements for detectors, refer to Fire & Gas (F&G) Detection Philosophy (1-CF0000-40-PHL-0005).

6.2.5

Escape and Evacuation

The project EER strategy and procedure for safe escape and evacuation of personnel is covered within the project Escape, Evacuation and Rescue Philosophy (1-CF0000-40- PHL-0006).

The following section outlines the criteria which should be considered when assessing the requirements for escape and evacuation.

6.2.5.1

Escape

All escape routes on facilities where a hydrogen sulphide hazard exists should be passable by personnel wearing self-contained breathing apparatus. Escape routes should be identified and marked as outlined in ADNOC HSE-OS-ST21. For fixed installations, a means of emergency communication with control room/emergency centre should be provided.

6.2.5.2

Evacuation

Self-evacuation is one of the most effective protective measures in response to hydrogen sulphide release. However, evacuation itself can be dangerous if not done properly:

• Alarm in process area will be set at 5ppm H2S detection;

• All alarms must be treated as real until proven false, and the appropriate response must be initiated (alarm sirens and beacons based on fixed alarms will generally only be activated on confirmed gas release);

• Small local releases should lead to local evacuation. Persons should retreat to a distance cross wind at which the personal hydrogen sulphide detector ceases to register;

• All alarms must be investigated by qualified personnel and conclusions reported. If the release is a nuisance release the alarm may be reset, but the person investigating should test the area with a handheld indicating instrument to attempt to determine the source;

• On hearing Toxic gas alarm personnel should move towards nearest Toxic Gas Refuge (TR/TGR). Emergency commander will give further instruction on evacuation from TR/TGR. A single instrument should never be the basis for a full site or plant evacuation unless it can be demonstrated to be highly reliable in the field;

• Escaping personnel shall wear EEBA/SCBA while escape, this will reduce potential

toxic exposure while escape;

• Wind direction should be indicated by windsocks, at least one of which should be visible from every outdoor location. Wind socks shall be installed at strategic location where they are always visible and along the escape route to guide personnel.

• Workers in any location should be able to escape to a “safe location” during an emergency with RPE in approximately 15 minutes. In a scenario where this is

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impractical due to the large plot size, one RPE changeover during evacuation and escape can be considered. TRs will also be provided with additional EEBA, that can be used during further evacuation from TR/TGR.

Evacuation routes must be wide enough to take the evacuation traffic without bunching or crowding, and certainly to avoid locking the crowd. For large groups of persons e.g. during major maintenance activities or during large construction projects, simulation should be used to determine whether evacuation is possible.

6.2.6

Temporary Refuge/Temporary Gas refuge (TR/TGR)

Temporary Refuge/Temporary Gas refuge (TR/TGR) should be provided to protect against the hazards associated with toxic releases. TR/TGR is protected locations where people can take shelter during a toxic gas release.

TR/TGR must be designed for purpose. In many cases where there is a possibility of hydrogen sulphide release, the release will either be at a small rate or will be short-lived, because the hydrogen sulphide inventory in equipment is limited. In other cases, such as close to sour gas or sour oil wells, or close to gas pipelines, gas releases may last for hours or days.

Temporary Refuge shall be protected for the duration required, to be determined in line with the ADNOC Escape Evacuation & Rescue Assessment (EERA) Standard (HSE-RM- ST07). Where the Standard duration cannot be met due to a credible scenario that can potentially result in a very long duration, a contingency plan for safe evacuation of personnel from the TR/TGR shall be developed.

TR/TGR which has been designed to protect against toxic gas shall include the following:

• Positively pressurised (minimum of 50Pa);

• Airtight (air exchange rates considering various leaks and number of door openings to

be determined and assessed in the EERA study);

• Means of fresh air such as stored air cylinder to ensure availability of air for the duration of TR/TGR considering maximum TR/TGR POB, potential leaks sources, door opening, etc.

• For positive pressure TR/TGR, entrances with double sets of doors (airlock facility with air curtain to purge toxic gas trapped with personnel entering the airlock) and located as far as possible away from sources of H2S. Interlock shall be in place to prevent both airlock doors being opened simultaneously or to alarm to warn of this condition. The location on the doors to buildings should be such that entry to the building is from side which is not directly facing to facilities to reduce the potential toxic gas ingress while in use;

• Doors shall be closed all the time except when in use, or be automatic closing, for example by magnetic hold open, released on gas detection. Attention should be paid to avoid hazards with automatically closing doors such as trapped Doors shall be closed all the time except when in use, or be automatic closing, for example by magnetic hold open, released on gas detection. Attention should be paid to avoid hazards with automatically closing doors such as trapped fingers,

• HVAC shall automatically shut off on detection of toxic gas at the air intakes, and dampers in the air intakes and exhaust shall close to shut in the building. Reliability of detection shall be as per requirements set in the 1-CF0000-16-SPE-0264;

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• Toxic gas detectors shall be provided at HVAC inlet as well as within the airlock. Alarm

provision shall be provided accordingly.

• A mechanism to allow manual initiation of HVAC shutdown from within the TR/TGR;

and

• TR/TGR leak tightness test should be carried out to ensure the gas tightness and to

confirm the air exchange rate considered in design of TR/TGR.

Offshore islands and installations will be equipped with TR/TGR and the measures described above should be considered. However, for offshore islands/installations, protection against fire and explosion will generally be needed also. This will be studied as part of Toxic Gas Refuge Impairment Assessment. For this assessment the impairment criteria shall be as defined in ADNOC HSE-RM-ST07. In all cases, TR/TGR shall be assessed for rate of gas ingress (due to loss positive pressurization), amount of fresh air needed for maximum POB within TR/TGR and corresponding maximum safe duration of use.

For small platforms such as well head platforms, provision of a TR/TGR can be difficult. Therefore, risks to personnel on these platforms shall be reduced to broadly acceptable or to the tolerable levels by other means, such as reducing exposure and providing emergency shutdown, use of EEBA / SCBA for the duration of evacuation to place of safety etc. Provision of rapid escape to attending boats, with boats preferably moored upwind (where possible) are additional means. Potential Exposure of boat crews to H2S and required protection measures shall be considered in the assessment.

TGR in drilling centres shall be provided with Air cylinders (200%) and with hook up type connection compatible with Breathing air apparatus.

6.2.7

Personal Protective Equipment

6.2.7.1

General Requirements

All PPE, including personal detectors, for use in hydrogen sulphide classified areas must be tested and calibrated as per manufacturer’s recommendation, or as per COMPANY experience, whichever gives the greater protection.

Where relevant a system must be in place to ensure that the shelf-life of consumables is not exceeded, and this system must be subject to audit.

6.2.7.2

Emergency Escape Masks (Positive Pressure)

Hydrogen sulphide at emergency levels can cause difficulty in vision and short-term blindness. Escape sets, must be of full-face positive pressure or positive pressure hood type with an air supply of at least 15 minutes.

Hydrogen sulphide can cause severe irritation of the eyes and temporary blindness. For this reason, hood type escape masks are preferred. Goggles may be of some use, but only if they are put on before exposure to H2S because the goggles themselves can fill with gas. Full face mask types or hood types with positive pressure air supply are freed from gas as air is passed from the storage bottle to the mask.

Escape masks shall be of adequate protection in accordance with the level of H2S concentrations expected, with a donning time of between 15-30 seconds. Escape masks shall comply to requirement of ADNOC HSE-OS-ST20.

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The protection offered by a given respirator is contingent upon the respirator user adhering to complete program requirements detailed in ADNOC HSE-OS-ST20.

6.2.7.3

Self-Contained Breathing Apparatus

Self-contained breathing apparatus (SCBA) should only be used for tasks such as sampling, emergency response, for rescue activities and for entering and leaving Red zones. Where work activities longer than a short time require breathing apparatus, units should be capable of transfer to an air-line fed mode (cascade system) which should be used during the work. This is because of the finite capacity of self-contained apparatus compared to the extended capacity when air-line fed. They should also be suitable and effective when worn on beards.

Sufficient SCBA sets of appropriate capacity should be ready and available at all times to allow response to identified emergencies, in addition to those sets in use by personnel working in Red Zones, or engaged in activities which require breathing apparatus.

6.2.7.4

Air-Line Breathing Apparatus

Air-line fed positive pressure breathing apparatus to be used as per ADNOC HSE-OS-ST21 requirement.

Air must be provided in compressed air bottles and cascaded to the breathing apparatus through a manifold. There must be an alarm set to warn of low air supply pressure and it must be monitored at all times whilst the system is in use.

Air line fed breathing apparatus must include a personal air reserve cylinder which can be used for escape in the case of air line supply failure.

The bottles must be refilled by a dedicated compressor located at a location free of hydrogen sulphide or other contaminant, and must not have cross connection to any other air or gas system.

Air for piped breathable air supplies must be taken from a safe place. Requirements are as follows:

• The breathable air system must be completely separate from any other air, gas or

nitrogen piping;

• There must be an alarm for low air supply pressure and exposure to the loop from

sunlight limited.

• Often the air will be supplied from trolley mounted cylinders. If this is the case, the compressor for cylinder filling must be located remotely at a definitely safe place. The compressor must be dedicated to cylinder filling.

• The air supply must be provided with a low-pressure alarm audible to those using the

air.

• No cross connections to gas or nitrogen piping, or to process air supplies, must ever

be installed;

• The air intake shall be located at safe distance from the discharge of diesel or petrol engine exhausts, including from portable compressor drives to ensure no ingress within the system. Where feasible two air intakes in opposite direction sufficiently away from these system shall be provided, this shall also take into account potential for release from adjacent facilities;

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COMPANY PROJECT No. 4700021770 CONTRACTOR PROJECT No: 67-00106 COMPANY DOCUMENT No. 1-CF0000-40-PHL-0003-00

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

• A multi gas alarm must be provided at the air intake, and the air intake shutdown following detection of contamination. The capacity of the air reservoir must be sufficient to allow the people under air to safely stop work and to evacuate to a safe location;

•

If a portable compressor is used, there must be an accumulator and the compressor must be continuously monitored to allow timely intervention in the event of failure or an emergency;

ACCOMODATION FACITIES WITHIN SOUR FIELD

As per ADNOC HSE-OS-ST21, Accommodation and canteen/restaurant where non- essential personnel are located at large, shall be located outside EAZ. However due to already constructed facility/operational constraints, where there is possibility of AEGL-3 (10 min) i.e. 76 ppm H2S exposure to accommodation area, TR/TGR shall be provided with capacity sufficient to house all personnel in line with ADNOC HSE-OS-ST21 requirements. This TR/TGR shall be provided with positive pressure safe air supply, either through compressed air cylinders. Offsite Emergency Plan shall be rolled out prior to commissioning.

Accommodation shall be provided with sealed windows, air lock and positive pressure.

BARGE REQUIREMENT WORKING IN SOUR FIELD

Barge working in field and having accommodation facility will be subject to same requirement as Sec 8 above. Barges without accommodation facilities should have provision of breathing air supply (cascade system) to designated muster area and necessary evacuation facilities and emergency plan in place.

APPENDICES

Appendix-1 Properties of Hydrogen Sulphide

Appendix-2 H2S Health Effects

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HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

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APPENDIX-1

PROPERTIES OF HYDROGEN SULPHIDE

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H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

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COMPANY PROJECT No. 4700021770 CONTRACTOR PROJECT No: 67-00106 COMPANY DOCUMENT No. 1-CF0000-40-PHL-0003-00

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

APPENDIX-2

H2S HEALTH EFFECTS

(NO OF PAGES: 2)

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HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

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COMPANY PROJECT No. 4700021770 CONTRACTOR PROJECT No: 67-00106 COMPANY DOCUMENT No. 1-CF0000-40-PHL-0003-00

HAIL & GHASHA DEVELOPMENT PROJECT PACKAGE 1 – OFFSHORE FACILITIES

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

Rev

DOCUMENT CLASS 1

Page 35 of 35

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ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

Drawing / Document Number, Title and Revision:

Doc Status Code:

Doc. No.:

1-CF0000-40-PHL-0003-00

Rev. No. :

CODE 2-COMMENTS AS NOTED

Doc Class:

Title:

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

CLASS 1

Discipline:

40-Process Safety Engineering

Pos No.

Page number

COMPANY Comments Description

COMPANY Originator NAME

CONTRACTOR Confirmation / Explanation

ACTION BY CONTRACTOR

1 2

06 06

Include Definition Include terms from clause 1.1. UAE Ministerial Order No. (32), 1982. Specifying Preventive Methods and Measures for Protecting Workers against Work Hazards HSE-RM-ST05 - Safety Integrity Levels (SIL) Determination Standard, HSE-GA-ST04 - Incident Notification, Reporting & Investigation Standard HSE-CE-ST03 - Fire and Rescue Operations Standard

HSE-OS-ST29 - HSECES Management Standard

HSE-CE-ST01- Emergency Response and Crisis Management Standard HSE-OS-ST27 - Hazard Communication Standard

HSE-OS-ST20 - Personal Protective Equipment Standard

HSE-OS-ST08 - Confined Space Standard

HSE-RM-ST01 - HSE Risk Management Standard

HSE-GA-ST05-Contractor HSE Management

Mr Kannan Perumal Mr Taqveem Panzoo Mr Saravanan Kalimuthu

Noted and Implemented Noted and Implemented This Law is not relevant to the object of the philosophy, therefore it has not been added.

A. Massoni A. Massoni A. Massoni

Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu Mr Saravanan Kalimuthu

This Standard is not relevant to the object of the philosophy, therefore it has not been added. This Standard is not relevant to the object of the philosophy, therefore it has not been added. This Standard is not relevant to the object of the philosophy, therefore it has not been added. Noted and Implemented

A. Massoni

This Standard is not relevant to the object of the philosophy, therefore it has not been added. Noted and Implemented

A. Massoni

Noted and Implemented

This Standard is not relevant to the object of the philosophy, therefore it has not been added.

A. Massoni

File: MacroCommentSheet_EPC 6

Page 1/2

ABU DHABI NATIONAL OIL COMPANY (ADNOC) GHASHA CONCESSION PROJECTS

Drawing / Document Number, Title and Revision:

Doc Status Code:

Doc. No.:

1-CF0000-40-PHL-0003-00

Rev. No. :

CODE 2-COMMENTS AS NOTED

Doc Class:

Title:

H2S (HYDROGEN SULPHIDE) PHILOSOPHY

CLASS 1

Discipline:

40-Process Safety Engineering

Pos No.

Page number

COMPANY Comments Description

COMPANY Originator NAME

CONTRACTOR Confirmation / Explanation

HSE-RM-ST06 - Control of Major Accidents Hazards (COMAH) Standard, Architectural Design Basis These limits only operation related personnel (essential) may be present in the area and not for all the personnel

Mr Saravanan Kalimuthu Parveen Faiz Mr Saravanan Kalimuthu

Noted and Implemented

Noted and Implemented This is already clarified in the paragraph: Only operations related personnel (essential) can be present in the area (EPZ).

Review and update as applicable

Parveen Faiz

Noted. Section updated as applicable.

A. Massoni

ACTION BY CONTRACTOR

A. Massoni

A. Massoni A. Massoni

File: MacroCommentSheet_EPC 6

Page 2/2

Project: Q-32855 - Saipem Hail & Ghasha Folder: Reference documents

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