21020-BAE-70000-PR-RP-7003

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REVISION CHANGE NOTICES

Revision Location of Changes Brief Description of Change

A1 First Issue Issued for IFR

A2 Section 3.2 Delete EC PW Pumps

Section 3.2 Revise operating temperature and produced water

scheme description.

Section 3.4 Revise produced water system description.

Section 3.4.1 Revise produced water hydrocylone description.

Section 3.4.2 Revise flotation unit description.

Section 3.5.3 Revise pressure at riser.

Section 3.6.3 Revise water injection pressure.

Section 4.3 Revise Fuel Gas Cooler tag number.

Section 4.3.3.4 Revise differential set point temperature.

Section 4.5.2 Add Seawater Heater description.

Section 4.6.1 Revise Flare KOD description.

Section 4.6.2 Revise Flare Condensate Return Pump description.

Section 4.6.3 Add propane cylinder information.

Section 4.10 Revise chemical injection system.

B1 Section 3.2 EC rundown stream water content specification

Section 3.4.4/ 3.5.1 PW transfer pump tag

Section 4.10.1 Oxygen scavenger tank blanketing requirement

Section 4.4 / 4.4.1 / 4.5.3 Dump caisson is deleted.

Section 4.6.1 Flare KO Drum sizing basis

Section 5 Section 5 – Inherently Safe Design deleted

C1 Relevant pages Changes denoted by right border

HOLDS TABLE

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1. INTRODUCTION

1.1 BACKGROUND

The Kraken Field is located in UKCS block 9/02b, approximately 400 km north east of Aberdeen in a nominal water depth of 116m.

The Kraken field development consists of the provision of subsea and FPSO production facilities to deliver stabilised oil to a shuttle tanker from 14 production wells.

The Kraken field development consists of the provision of subsea and FPSO production facilities to deliver stabilized oil to a shuttle tanker from 25 wells (14 producers and 11 water injectors). The Kraken product is heavy oil with a gravity of approximately 13.7° API. The development of Kraken requires multiple drilling/production centres which will be subsea developments tied back to the FPSO. The FPSO is designed as a harsh environment production facility. HSPs in each production well supplied with power water from the FPSO are provided lifting the viscous crude from the low pressure reservoir. Water injection facilities are provided for reservoir pressure support, voidage replacement and to sweep the oil to the producers.

As a result of the low GOR, associated gas and crude will be used for power generation, with the possibility of import gas in later life. Gas import via a dedicated import pipeline tied into an existing 3rd Party trunk line is a future possibility and therefore included.

The heavy oil forms a strong viscous emulsion with water; however, this will be managed with the hydraulic submersible pump (HSP) power water, which mixes with the crude oil at the well head producing more favourable separation of oil and water phases.

BAB will base the FPSO on the existing tanker PRISCO ALCOR (the Tanker), which shall undergo an extensive conversion programme for conversion to the FPSO role. The FPSO shall sail under its own power from conversion yard in Singapore to a port in Northern Europe (Rotterdam) and then will be towed from the port to the field for hook-up and installation.

1.2 PROJECT OBJECTIVES

The overall project objective is to exploit the reserves in the Kraken field in a timely and cost effective manner that maximises the recovery, and meets EnQuest’s HSSE policy, value, strategy, operability, technical and deliverability targets.

1.3 DOCUMENT SCOPE

The purpose of this document is to provide the description of the process facilities and utility systems on the Kraken FPSO Topsides.

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1.4 ABBREVIATIONS

The following terms are generic to the Kraken Field Development Project and may be referred to in this document:

List of Abbreviations Abbreviation Definition

AC Alternating Current

API American Petroleum Institute

BAB Bumi Armada Berhad

BFW Boiler Feed Water

BOPD Barrels of Oil Per day

BS&W Base Sediment and Water

BWPD Barrels of Water Per Day

CFU Compact Flotation Unit

EC Electrostatic Coalescer

FG Fuel Gas

FPSO Floating Production Storage & Offloading

FWKO Free Water Knock Out

GOR Gas Oil Ratio

HP High Pressure

HSP Hydraulic Submersible Pump

ISO International Standards Organization

LAT Lowest Astronomical Tide

LP Low Pressure

MBD Thousand Barrels per Day

MMscfd Million standard cubic feet per day

MWe Mega Watts electrical

ppb Parts per billion

ppmv parts per million by volume

pptb pounds per thousand barrels

PW Produced Water

RVP Reid Vapour Pressure

SRP Sulphate Reduction Package

TDS Total Dissolved Solids

TVP True Vapour Pressure

UKCS UK Continental Shelf

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2. OVERVIEW

2.1 GENERAL

The main facilities on the FPSO are:

• Well Fluid Collection facilities, HSP Power water and WI distribution facilities located on Turret of the FPSO

• Well Fluid Separation facilities • Storage of the Stabilized Oil Produced

• Utilities required for Process the Fluids and Operating the FPSO

• Facilities for treating the produced water to meet water Injection and HSP Power Water Specifications

• Facilities for transferring the Oil from the FPSO to the Shuttle tankers This document should be read in conjunction with PFDs [Ref.: 3]_{and UFDs}[Ref.: 4]

Hydraulic submersible pumps (HSPs) located in the reservoir are driven by high pressure water (HSP power water), for artificially lifting the well fluids from the low pressure reservoir of Kraken field. The produced water separated from the fluids is treated on the FPSO and pumped by HSP Power water Pumps and supplied back to the HSP pump drive.

The HSP power water from the outlet of HSP turbine drive combines with the reservoir fluids and is pumped back along with the well fluids to the FPSO by the HSP pumps.

The well fluid is collected from three clusters of wells and from each clusters the well fluids are routed to the FPSO through two subsea flow lines. The well fluids are received on the FPSO through six production pipeline risers.

There are two trains of well fluid separation having FWKO, LP separator and Electrostatic Coalescer. The oil separated from the separation facilities is stored in the storage Tanks located in the hull of the FPSO.

The produced water is treated to remove solids and oil to meet specifications of HSP power water and WI water.

The separated gas from FWKO vessel is routed to the Fuel gas conditioning unit. LP gas from the LP separator is cooled by sea water in a Shell and tube exchanger and sent to LP Gas KO Drum to separate the liquids condensed. The separated gas from LP Gas KO Drum is compressed in the compression system before it is combined with the gas from the FWKO Vessel.

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Sea Water is filtered, treated to reduce sulphates and then de-aerated to remove dissolved oxygen for supplementing the produced water for Water Injection and HSP Power water as required.

Steam is used for process heating on topsides, as the motive force for the cargo offloading pumps in the hull. The hull cargo storage tanks also use steam to maintain produced crude at the correct temperature. Steam is generated from 3 x 50% steam boilers, which can be fired on crude oil, fuel gas or diesel. The steam from these boilers will be generated at 16 barg. Additional steam generation comes from the Waste Heat Recovery Unit on the Power Generators, which produce steam at 5.2 barg. The 16 barg steam is supplied to the hull to drive the cargo pumps as well as other miscellaneous users. Steam at 10 barg (let down from 16 barg system) is used to heat the crude oil storage tanks in the hull. A pressure let down facility is provided to generate steam at 5.2 barg from the steam at 16 barg and one more let down level of steam from 5.2 barg to 1.5 barg. Steam at 5.2 barg and 1.5 barg is used to heat the process streams where necessary.

The utility systems on the FPSO include: • Diesel System

• Instrument Air and Utility air systems • Nitrogen Generation system

• Flare and Drain systems • Steam generation system • Power Generation system • Essential Power Generator • Inert Gas generation system

• WHRUs

• Fuel Gas compression, gas import and Fuel Gas conditioning system • Fresh water generation and distribution system

• Electrochlorination system • Chemical Injection system • SW Treatment system

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• Diesel Biocide Injection System • Hydraulic Oil Transfer System Design Life

The design life of the Kraken Facilities is 25 years.

2.2 DESIGN CAPACITIES AND SPECIFICATIONS

The Kraken topsides design capacities are as follows (Ref. 1, Section 7.5.1):

Topsides Design Capacities

Peak liquids production rate 460 MBD

Nameplate oil production 80 MBD

Nameplate gas handling 20 MMscfd

Nameplate water production 275 MBD

Nameplate HSP production 225 MBD

Nameplate water injection 275 MBD

Nameplate gas import 15 MMscfd

Nameplate oil offloading 4500 m3/h

Nameplate treated seawater makeup 80 MBD

The product crude oil specification is as follows (Ref. 1, Section 7.6.1):

Parameter Specification

TVP 0.9 bara at 50oC (crude storage temp)

RVP 0.76 bara (11 psia)

BS&W < 0.5 vol%

SALT < 70 pptb

Dispersed oil-in-water (for overboard discharge), shall target ≤ 15 ppmv max and at all times it will be ≤ 30 ppmv as per current legislation (Ref. 1, Section 7.6.3)

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3. PROCESS FACILITIES

3.1 SUB SEA PRODUCTION FACILITIES

The subsea production facilities consist of mainly:

• Four Drill Centres of subsea Production Wells and WI wells (Drill centres 3 & 4 are daisy chain arrangement)

• Six subsea production pipe lines and risers at the turret of FPSO • A test header connecting all wells for testing the well fluid flow rates.

• Three HSP Risers, Power Water subsea pipe lines and facilities for distribution of Power Water to the HSP pumps

• Three WI Risers and injection facilities • One gas import riser

• Three Subsea umbilical control system

3.2 WELL FLUID SEPARATION SYSTEM

Well fluids commingled with HSP power water arrive at the FPSO via production risers and are routed to the production manifolds and test manifold. The turret accommodates the swivel stack which allows the vessel to weathervane freely. On the FPSO topsides, Well fluids are processed in two parallel oil processing trains A and B, each sized for 50% of design capacity. Each of the two trains has a capacity to process well fluid to yield 40 MBD of stabilized crude oil to storage.

Each oil train consists of the following equipment:

Equipment Title Train A Train B

Free Water Knock Out (FWKO) Drum 30-VS-1110 30-VS-1120

Oil/Oil Exchanger 30-HP-1110 30-HP-1120

Oil/PW Exchanger 30-HP-1111 30-HP-1121

Oil Heater 30-HE-1112 30-HE-1122

LP Separator 30-VS-1210 30-VS-1220

Electrostatic Coalescer 30-VE-1211 30-VE-1221

LP Separator PW Pumps 30-PC1210A/B 30-PC1220A/B

Oil Transfer Pumps 30-PC-1212A/B 30-PC-1222A/B

Oil Cooler 30-HP-1213 30-HP-1223

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The well fluids enter the FWKO Drum 30-VS-1110, which separates free water and gas from the well fluids. The FWKO operates at approximately 9.5 barg and 45°C. The oil flows over a weir into the oil compartment of the vessel and under level control exits to the Oil/Oil Exchanger 30-HP-1110. Due to the high viscosity and high gravity of the Kraken crude, the Oil leaving the FWKO Drum may contain up to 40% of emulsified water and considerable quantity of gas as carry under gas (20% of total gas liberated in FWKO Drum considered in design). The oil level in the FWKO Drum is controlled by a LCV located in the FWKO Drum oil outlet line. The produced water leaving FWKO Drum will contain around 1% of oil in water. The emulsified oil from the FWKO Drum is heated by exchanging heat with the crude oil from Electrostatic Coalescer in Oil/ Oil exchanger 30-HP-1110 to a temperature of about 68 °C and then it is heated by hot PW to a temperature of about 108 °C. The Oil stream is then heated to 140 °C by steam in the oil heater 30-HE-1112 before it enters the LP separator. The oil feeding the oil heater is a combined stream of oil from the FWKO Drum, reject oil stream from the PW treatment system, condensate from the LP Gas FWKO Drum and recovered oils from Slop and Off-spec tanks from Hull.

The operating pressure of LP Separator 30-VS-1210 is maintained at 3.4 barg under back pressure control of the outlet gas. The LP separator 30-VS-1210 separates most of the emulsified water due to a decrease in viscosity at 140 °C and it is expected that the oil leaving the LP separator will contain <10% of emulsified water. The oil content in the produced water leaving the LP Separator will be around 2000 ppm.

Oil from the LP Separator 30-VS-1210 is pumped by the oil transfer pumps 30-PC-1212 A/B into the Electrostatic Coalescer 30-VE-1211, which is operated at a pressure of 6 barg. The oil from the Electrostatic Coalescer 30-VE-1211 is sent to the Oil/ Oil exchanger 30-HP-1110 under oil level control in the EC 30-VE-1211. The EC agglomerates the water droplets by the collision effect under the influence of high AC voltage. The water content in the oil leaving the EC will be 0.3 % v/v BS&W. The oil content in the produced water leaving the EC will be around 1000 ppm.

Treated oil from the EC 30-VE-1211 at 140 °C is cooled in the Oil/Oil exchanger 30-HP-1110 to about 90 °C and then it is further cooled in the Oil Cooler against treated seawater to cool to 50 °C for storage. The water content in the oil sent to storage will be 0.5% v/v BS&W. Cooling medium is switched over to the filtered seawater from treated seawater when SRP is not in operation.

The produced water from Electrostatic Coalescer is sent back to LP Separator under level control. The produced water stream from the LP Separator 30-VS-1210 is pumped to a pressure of around 12 barg and passed through the Oil/ PW Exchanger 30-HP-1111, where it is cooled to about 80 °C by exchanging heat with the oil preheated in the Oil/Oil exchanger 30-HP-1110. The cooled stream is sent to the LP Separator Deoiling Hydrocyclone within the produced water treatment system. The produced water from FWKO Drum which is at 9.0 barg and 45°C is sent to FWKO Drum Deoiling Hydrocyclone within Produced Water Treatment Package.

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To ensure water content in the inlet oil to the Electrostatic Coalescer satisfies minimum requirements for coalescer performance, a connection is provided from Electrostatic Coalescer produced water to oil compartment of LP Separator.

The gas streams from each FWKO Drum and the Test Separator are combined and sent to the fuel gas system.

The TVP specification of 0.9 bara at 50°C for the export crude oil is met by the coincident temperature and pressure conditions in the LP Separator. At a temperature of 140°C, the pressure required is 3.4 barg.

3.3 TEST SEPARATOR

The well testing facility provided, consists of a test manifold at upstream of the turret and a Test Separator 25-VP-1130. Any one of the well can be selected for testing. The oil from the Test Separator exits under level control and is combined with the oil leaving the FWKO Drums of the two oil trains, and the gas joins the combined gas from the two FWKO Drums. The Oil from the Test Separator can be combined with outlet oil of any one of the FWKO Drums or it can be distributed to both trains.

The separated water from the test separator is routed under interface level control to the FWKO drum, however, a facility is provided such that it can be routed to the PW outlet of the FWKO vessels of either oil train. In effect, the Test Separator operates in parallel with the FWKO Drums in the two trains.

A backpressure control valve is provided in the Test Separator gas outlet line to allow operation at higher pressures than the FWKO Drum. This control valve also provides stable operating conditions in the Test Separator necessary for metering purposes. A pressure-controlled vent to flare is also provided to accommodate any high gas flows during well testing.

3.4 PRODUCED WATER TREATMENT SYSTEM

Part of the Produced Water (PW) Treatment system is supplied as a package item i.e. Hydrocyclones, Compact Flotation Units (CFUs), Flotation Recycle Pumps, PW Degasser, PW Degasser Oil Pumps. The detailed operating and control philosophy shall be provided by the supplier. The following presents an overview of the Produced Water Treatment system. This section needs to be read in conjunction with supplier P&IDs and Process Description [Ref: 11, 12]_.

Produced water can contain oil in water up to 10,000 ppmv at the inlet to the hydrocyclones. The PW is treated for use as power water for driving the downhole HSP turbines) and for water injection. The water treatment equipment is designed to achieve the oil-in-water specification of max. 30 ppmv, and target the more stringent specification of 15 ppmv. A combination of hydrocyclone deoiling and gas flotation technology is used to achieve this specification.

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The Produced Water from FWKO Drum, LP Separator and Electrostatic Coalescer is treated in the two parallel trains of Produced Water Treatment packages, each package is sized for 50 % of the design capacity. The produced water stream from FWKO Drum and LP Separator (Electrostatic Coalescer produced water stream is routed to LP Separator) is routed to dedicated de-oiling hydrocyclones (i.e. 2 x50 % de-oiling hydrocyclones for FW KO Drum and 1 x 100% de-oiling hydrocyclone for LP Separator). Partially treated produced water from the FWKO Drum and LP Separator Hydrocyclones is routed to Flotation Units for further treatment to meet the required overboard discharge oil-in-water specification. The Produced Water Treatment package will reduce the treated produced water oil content down to 30 ppm (≤ 30 ppm) without chemical injection and down to 15 ppm (≤ 15 ppm) with chemical injection. Each PW Treatment train consists of the following equipment:

Equipment Title Train A Train B

FWKO Drum Hydrocyclones (2 x 50% per train) 30-VJ-1610A/B 30-VJ-1620A/B LP Separator Hydrocyclone (1 x 100% per train) 30-VJ-1613 30-VJ-1623 Flotation Units Stage 1 (2 x 50% per train) 30-VV-1611A/B 30-VV-1621A/B Flotation Units Stage 2 (2 x 50% per train) 30-VV-1612A/B 30-VV-1622A/B PW Degasser (1 x 100% per train) 30-VG-1615 30-VG-1625 PW Degasser Oil Pumps (2 x 100% per train) 30-PC-1611A/B 30-PC-1621A/B Flotation Recycle Pumps (3 x 50% per train)

35-PC-1612A/B/C

35-PC-1622A/B/C

PW Transfer Pumps (2 x 50% per train + common spare)

35-PC-1610A/B/C*

35-PC-1620A/B

* 30-PC-1610C is a common spare for Train A and B

3.4.1 FWKO Drum Hydrocyclones (30-VJ-1610A/B & 30-VJ-1620A/B)

The primary separation step is performed by liquid-liquid deoiling Hydrocyclones. The Hydrocyclones operate in a 2 x 50% vessel configuration. One Hydrocyclone vessel is designed for a flow rate of 762 m³/h.

The water outlet flow rate from the Hydrocyclones is controlled to maintain a constant liquid interface level in the FWKO Drum (30-VS-1110/1120). This is achieved via level control valves located in the water outlet header of the Hydrocyclones. The reject flow rate from Hydrocyclones is controlled to maintain a constant differential pressure ratio of 1.6 between the inlet to reject and the inlet to outlet (underflow) of the Hydrocyclones. This is achieved via a pressure control valve located in the reject header of the Hydrocyclones. The reject flow rate is approximately 2.5% of the inlet flow rate during normal operation. The oily reject is routed to the PW Degasser (30-VG-1615/1625).

3.4.2 LP Separator Hydrocyclones (30-VJ-1613/1623)

The primary separation step is performed by liquid-liquid de-oiling Hydrocyclones. The Hydrocyclone vessel is designed for a flow rate of 219 m³/h (1x 100%).

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The water outlet flow rate from the Hydrocyclone is controlled to maintain a constant liquid interface level in the LP Separator (30-VS-1210/1220). This is achieved via level control valves located in the water outlet line of the Hydrocyclones. The reject flow rate from the Hydrocyclones is controlled to maintain a constant differential pressure ratio of 1.6 between the inlet to reject and the inlet to outlet (underflow) of the Hydrocyclones. This is achieved via a pressure control valve located in the reject outlet line of the Hydrocyclones. The reject flow rate is approximately 2.5% of the inlet flow rate during normal operation. The oily reject is routed to the PW Degasser (30-VG-1615/1625).

3.4.3 1st & 2nd Stage Flotation Units (30-VV-1611/1612/1621/1622 A/B) and Flotation

Recycle Pumps (30-PC-1612/1622 A/B/C)

The water from the FWKO Drum Hydrocyclones and LP Separator Hydrocyclone is combined and passed to the Compact Flotation Units (CFU). The CFU’s are configured as 2 x 50% sub-trains. Each sub-train includes two stages of separation.

The produced water is fed through two tangential inlets in the CFU. The tangential inlets create a swirl within the CFU that results in a centrifugal force being applied to the oil, water and gas in the stream. The use of two tangential inlets provides maximum stability of the swirl and centrifugal forces.

The centrifugal force will force the more dense water to the outside of the lighter oil and gas to the center as the fluid rise up the vessel. The oil will rapidly rise due to the increasing velocity of the central core caused by the gas bubbles. Oily water and gas are taken off from a central dip tube at the top of the vessel. This multiphase stream is then passed to the PW Degasser (30-VG-1615/1625). Although the flow of oily water is manually fixed (set during commissioning to approximately 2% of the operating flow of the vessel) it can periodically be optimized for operational efficiency and to minimize overflow.

While the oil and gas migrate to the center and top of the vessel, the water will rise more slowly on the outside. At the top of the vessel the upwards velocity of the water is halted in a wider chamber which allows time for any fine oil droplet or gas bubbles to totally disengage. The cleaned water then passes over an internal baffle to the outer annulus.

The first CFU (30-VV-1611/1621 A/B) has two stages of flotation performed by two gas eductors. One eductor is used on the common inlet and one to inject gas into the outer annulus (essentially acting as a second stage of flotation). The second CFU (30-VV-1612/1622 A/B) is a single stage unit with also two gas eductors. For this vessel, both eductors are located on the tangential inlets (one for each tangential main inlet). This unit does not inject gas into the outer annulus, so as to prevent gas carry under to downstream Produced Water Transfer Pumps.

A water recycle stream is taken from the second CFU using the Flotation Recycle Pumps (30-PC-1612/1622 A/B/C) and is fed to the gas eductors. This recycle stream passes through the gas eductor, which is used to suck gas from the PW Degasser and create a gas / water mixture (approximately 50 / 50% based on volumetric fraction) at the eductor discharge. This mixture is injected into the CFU to facilitate flotation. The Flotation Recycle Pumps are

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organized as 3 x 50% units (for each train), one for each active CFU sub-train and a common spare (each pump supplies two CFUs).

The CFUs operate essentially “flooded”, with a dip tube in the top of each CFU, through which the reject stream (mixture of water, oil and some gas) from the CFU is routed to the PW Degasser. This dip tube extends a small distance below the liquid level and allows a small gas cap to form above the liquid at the top of each CFU. This gas cap acts as a buffer volume for pressure variations. The second stage CFU is controlled to a constant pressure in the gas cap space. The pressure controller (PC) signal is sent to the pressure control valve (PV) on the discharge of the Produced Water Transfer Pumps. There is a PC on each of the 2 x 50% second stage CFUs. The individual PC signals are compared, with the higher of the signals being selected to modulate the PV on the pumps discharge. The flow of water between the first and second stage CFU requires no control.

In the event of some upset causing reduced downstream demand (e.g. trip of HSP Power Water Pump, trip of Produced Water Transfer Pump, malfunction of PV or XV on pumps discharge to closed position etc.), the inflow to the CFUs will exceed the outflow, causing the gas cap space to be compressed. The PC on the CFU is split-range with 0-50% output modulating the PV on the Produced Water Transfer Pumps discharge, and 50-100% output sending a high CFU pressure override signal to the PV on the Produced Water Transfer Pumps discharge dump line. Increased pressure in the CFU therefore results in short-term dumping of produced water to either the off-spec tank or overboard, depending on the valve line-up on the dump line. These upset events are short-term, as the HSP power water flow into the front end of the process (FWKO Drums) will also reduce soon after the reduced downstream demand is initiated. The intent is to avoid a process trip of the produced water treatment system/oil separation train in the event of such short-term upsets. Transient simulations are being performed which will assist in establishing the speed of response of PC loop to these upsets, and time taken for flow into the FWKO Drums to reduce.

3.4.4 PW Degasser (30-VG-1615/1625) & PW Degasser Oil Pumps (30-PC-1611/1621A/B)

The oily reject streams from the Hydrocyclones and the oily / gas reject from the CFUs are sent to the PW Degasser. The gas from the PW Degasser is re-used as flotation gas for the CFUs via gas eductors as described in previous section. The pressure inside the PW Degasser is maintained, as excess gas is vented to the Flare KO Drum. Fuel Gas is available for gas blanketing or in case of upset condition (i.e. sudden drop of liquid level in the PW Degasser).

The oily water from the PW Degasser is pumped by 2 x 100% pumps (30-PC-1611/1612 A/B) to the inlet of the Oil Heater (30-HE-1112/1122). A control valve is located in the discharge line of the pumps for level control of the PW Degasser. A minimum flow recycle loop is included for the pumps. A magnetic flow meter located in the discharge header of the pumps is used to control the recycle flow rate.

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3.4.5 Off-Spec Produced Water

An online oil-in-water analyser is provided on the suction header of the PW Transfer Pumps such that in the event of high oil-in-water, the offspec water is routed to the off-spec tank. The target oil-in-water content of the produced water stream from the Produced Water Treatment package is maximum 30 ppmv, but it is expected that actual oil-in-water content will be less than this (particularly with the use of chemicals). Therefore 30 ppmv is considered as a high oil-in-water level. At 30 ppmv, the oil-in-water analyser will close 35A/B-XV-1612 on the produced water overboard dump line, and will open 35A/B-SDV-1613 on the line to the offspec tanks. The initial realignment of these valves at 30 ppmv ensures that offspec water is not discharged overboard if the oil-in-water content increases further to 50 ppmv. At 50 ppmv, the oil-in-water analyser will close 35A/B-XV-1617 on the discharge of the PW Transfer Pumps. This will cause the overboard dump PV to open in response to increasing pressure upstream of 35A/B-XV-1617, and the offspec produced water will be routed to the offspec tanks via 35A/B-SDV-1613.

3.4.6 PW Transfer Pumps

Oil free water from the CFUs is pumped by PW transfer pumps PC-1610 A/B/C and 35-PC-1620A/B for distribution to HSP power water pumps and WI pumps through a common manifold. The PW transfer pump 35-PC-1610C is a common spare for Train A and B. For turndown scenarios, individual pump minimum flow control recycle lines are provided for protection of the pumps. The minimum flow recycle line is routed back to the PW Treatment package.

High and low pressure alarms are also provided at each pump discharge to detect any abnormal discharge pressure.

The PW from the discharge of the PW Transfer pumps is routed via respective WI/HSP Fine Filtration Packages 35-AY-6310 before it is distributed to the HSP Power Water Pumps and the WI Pumps. The discharge pressure of PW Transfer Pumps is sufficient to meet the required pump suction pressures at HSP Power Water Pumps and the WI Pumps.

Pressure control is provided on the common discharge header of the PW Transfer Pumps to dump water overboard through a dedicated dump valve when the pressure in the header increases due to lower demand in WI and HSP Power Water systems or trip of WI and HSP Power Water Pumps.

3.5 WI/HSP FINE FILTRATION PACKAGE (35-AY-6310)

The produced water from the PW Transfer Pumps is routed to the WI/HSP Fine Filtration Package for sand removal. The WI/HSP Fine Filtration Package removes particles down to 10 microns size, which is the specification for the WI system. The specification for the HSP Power Water system is 80 microns, but the filtration duty for both systems is combined into a single package to maximise turndown. The package consists of 6 x Desanding Hydrocyclone vessels (35-VJ-6310A/B/C/D/E/F) equipped with 1” liners.

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There are three different designs of Desanding Hydrocyclone vessels to achieve the required performance across the complete flow rate range. For the different operating configurations required for various flowrates, refer to vendor’s Process Description[Ref: 12]_{. The differential}

pressure between the inlet and the water outlet at the design flow rate is 5 bar. A differential pressure transmitter is available for indication.

The sandy water reject (underflow) is 1% of the incoming flow rate. The underflow is open continuously, except when the Sand Cleaning Package (20-AY-6330) is receiving sandy water from the sand jetting system of the FWKO Drums and Test Separator.

The sandy water is sent to the Sand Cleaning Package for cleaning of the sandy water. A level switch with high level alarm is available for indication (e.g. build up of solids due to operation with closed underflow). A dilution line is available to improve drainage of the vessels when required (e.g. after operation of the Sand Cleaning Package for cleaning of sandy water from the sand jetting system of the separators).

The filtered water is distributed to the HSP Power Water Heater 40-HE-6311 and WI Heater 40-HE-6310 to meet respective temperatures of 55 °C and 50 °C.

3.6 SAND CLEANING PACKAGE (20-AY-6330)

This section should be read in conjunction with the supplier’s Produced Water Treatment Package Process Description and P&IDs[Ref: 11, 12]_.

The Sand Cleaning Package is designed to accumulate and clean sand from the WI/HSP Fine Filtration Package and from sand jetting operations in the FWKO Drums and Test Separator. Oily water from the Sand Cleaning Package passes to the Slop Tank while the clean solids (with <1,500 mg/kg oil on discharge and expected oil-in-water content of <30 ppmv) are sent for overboard disposal.

Normally the WI/HSP Fine Filtration Package discharges into the Sand Cleaning Vessel. When the FWKO Drum and Test Separator are to be flushed of solids (intermittent sand-jetting), the desanding hydrocyclone underflow discharge from the Fine Filtration Package is temporarily isolated. During this operation solids accumulate in the cones of the desanding hydrocyclone vessels until the underflows are brought back online.

The FWKO Drum and Test Separator sand jetting systems are designed for a flow rate of 70 m³/h each. The combined underflow flow rate from the desanding hydrocyclones is 33.3 m³/h. An additional water flow of 36.7 m³/h is sent to the eductor and through the recirculation line to the sand cleaning hydrocyclone inlet to maintain a flow of 70 m³/h. It is important that this full flow rate is maintained in order to ensure the design performance of the Sand Cleaning hydrocyclones.

The accumulator section is designed to collect the volume of sand at a design rate of 1300 kg/d. At the maximum solids loading the vessel is designed to be discharged of solids once

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per day. An eductor is mounted beneath the vessel for the purpose of sandwash recirculation. The sandwash process is continuously recirculating the sand in the vessel. A flushing line is incorporated into the cone section in order to assist in the flushing of solids to sandwash, or overboard discharge, in the event of bridging. The flushing flow rate of 36.7 m³/h is divided between the eductor motive and suction lines.

The Sand Cleaning Package incorporates actuated isolation valves in order to switch to the different modes of operation of the package. The discharge operation can begin either on a high sand level signal in the accumulator section or on a daily timer. If operated on a timer, the high level signal must be set to override the timer in the event of abnormally high solids loading.

3.7 HSP POWER FLUID SYSTEM

The HSP Power Water system consists of:

Equipment Title Tag No

HSP Power Water Heater 40-HE-6311

HSP Power Water Pumps 40-PC-6311A/B/C/D

The treated water from the WI/HSP Fine Filtration Package is divided between the HSP Power Water and WI systems; with priority being given to the HSP Power Water system (the priority is managed by the control logic).

The stream used as HSP Power Water, is heated to 55°C by steam in the HSP Heater. During start-up to meet HSP Power Water requirement, make-up treated seawater is made available at a flow rate up to 530 m3_{/ h (80,000 BPD).}

Each HSP Power Water Pump has a capacity of 500 m3_{/h. The pressure of the HSP Power}

Water is raised to 330 barg at Riser Top by the HSP Power Water Pumps and routed to the HSP power water manifold in the turret. The HSP Power Water Pumps are provided with a minimum flow line in order to dump the water to overboard and protect the pump from cavitating during turn down.

High pressure water from the HSP Power Water Pumps combines into a common header and is routed to the turret where it is distributed to the three HSP Power Water subsea pipelines.

At the subsea power water PLETS the water is distributed to power the downhole HSP pump turbines.

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3.8 WATER INJECTION SYSTEM

The water injection system is designed to inject a blend of treated produced water and low sulphate, deaerated seawater into the reservoir at a pressure of 80-135 barg at top of riser. Water injection is required to maintain downhole reservoir pressure and for the disposal of excess produced water.

The water injection system consists of:

WI Heater 40-HE-6310

WI Pumps 40-PC-6310A/B/C

The filtered water from the W I/HSP Fine Filtration Package is combined with make-up water from the treated seawater system and is routed to the WI Pumps via the WI Heater 40-HE-6310. The WI stream is heated to 50°C by steam in the WI Heater. The water is routed from the WI Pumps to the WI manifold in the turret for distribution to the sub-sea WI well clusters. Each WI pump has a capacity of 915 m3_{/h and the normal discharge pressure is}

about 80 - 135 barg. The pressure at the discharge of the WI Pumps can be raised to 160 barg at Riser Top, but at lower flow, to clear any blockages which may have built up.

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4. UTILITY SYSTEM

4.1 INSTRUMENT AIR AND UTILITY AIR SYSTEM

4.1.1 Instrument Air Process Description

Instrument Air system consists of 3 x 50% air compressors 35-AY-5630A/B/C of 1250 Sm3_/hr

(each) and 2 x 100% air dryers’ 35-AY-5631A/B, of 2500 Sm3_{/hr. Air intake from the}

surroundings to the compressors will be compressed and dried before sending to Instrument Air Receiver 35-VA-5630.

The system consists of the following:

Equipment Title

Tag No

Air Compressor Package (3 x 50%) 35-AY-5630A/B/C

Instrument Air Dryer Package (2 x 100%) 35-AY-5631A/B

Air Receiver 35-VA-5630

Each Air Compressor Unit has been sized to meet the air requirements of the FPSO topsides requirements; one unit in lead under normal operation, the second unit on lag mode ready to start automatically on demand. The Air compressors operate in a lead/lag 1 /lag 2 configuration. Selection of the lead and lag unit will be through selector switches on the Local Control Panels. The instrument air header pressure is maintained by modulating the pressure control valve located downstream of the Air Receiver 35-VA-5630 to the instrument air supply header.

Instrument air is used to operate pneumatic valves such as BDV, SDV and various control valves on the FPSO topsides and Turret. Besides these topsides consumer’s, instrument air is also provided to consumers in the Hull.

4.1.2 Utility Air System

Utility air is drawn from the Air Receiver 35-VA-5630 and is supplied at the same pressure and quality as instrument air. Utility air is available for use as motive air for air powered tools. Instrument air supply is given priority over utility air. At low pressure in the Instrument Air header, the supply of utility air is stopped.

4.2 NITROGEN SYSTEM

Air for the Nitrogen Generation Package Skid 35-AY-5910 is supplied from outlet of dryer. Nitrogen generator shall be designed for 97% purity of 204 Sm3_{/hr capacity. Nitrogen from}

the nitrogen generation package is stored in the Nitrogen Receiver 35-VA-5910.The details of Nitrogen Generation Package Skid will be provided by the supplier.

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Nitrogen generated at the maximum pressure of 7.5 barg is supplied to the following users:

• Utility stations including Hull/Turret (intermittent) • Flare purge (backup to fuel gas)

• Offloading Line Flushing (intermittent)

• Methanol/Oxygen Scavenger Tank Blanketing (intermittent) • Pressurisation of FWKO drums during start up

A PCV downstream of the nitrogen receiver controls the supply pressure at 3 barg. Nitrogen supply to the intermittent users is by manual valves.

The nitrogen generation package includes an intensifier unit and nitrogen quad (16 bottles) to store high pressure nitrogen, which will be used during import fuel gas line-up after shutdown (to equalize pressure across the riser ESDV). The same nitrogen bottles will be used to pressurize the FWKO Drum during start-up, by using pressure regulator to throttle pressure from 250 barg to 9.5 barg.

4.3 FUEL GAS SYSTEM

The total gas produced by the two oil trains is used as fuel gas. Fuel gas is also imported to supplement the Fuel gas production on the FPSO in future when the field declines. The fuel gas system consists of the following equipment:

LP Gas Cooler 25-HE-1230

LP Gas KO Drum 25-VG-1230

LP Gas KO Drum Pumps 25-PC-1230A/B

Fuel Gas Compressor Package (Note 1) 25-AY-6110/6120

Fuel Gas KO Drum 25-VG-6110

Fuel Gas Filter Coalescer 25-FS-6113A/B

Fuel Gas Superheater 25-HS-6111

FG Import Heater 25-HS-6112

Import FG Fiscal Metering Package 25-AY-2902

Notes:

1. Each Fuel Gas Compressor package consists of a Screw Compressor

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(25-HA-6110/6120), a Discharge Scrubber (25-VG-6111/6120, as well as the package lube oil circulating system (filters, pumps, coolers).

4.3.1 LP Gas Cooler / KO Drum and Fuel Gas Compressors / Cooler

The combined gas from the two LP Separators at 3.4 barg and 140°C is cooled to 30°C against seawater. Condensed liquids (mainly water) are knocked out in the LP Gas KO Drum. The separated gas is then sent to the Fuel Gas Compressors 25-KS-6110/6120 (2 x 100%) and compressed to 8.5 barg. The discharge gas is cooled to 45°C in the discharge Air Cooler 25-HE-6110 and then combined with the gas from the FWKO Drums and the Test Separator. The comingled gas is sent to the Fuel Gas KO Drum 25-VG-6110, where any liquid condensed out is separated. The condensed liquid is sent under level control to downstream of LP Gas KO Drum Pumps 25-PC-1230A/B. The liquid from the LP Gas KO Drum 25-VG-1230 is pumped by 25-PC-25-VG-1230 A/B under level control to the inlet of Oil heater 30-HE-1112 in Train A or to the inlet of 30-HE-1122 of Train B (using manual diverter valves).

Gas from the Fuel Gas KO Drum is passed through a Filter Coalescer to remove any entrained liquid and is heated to the desired degree of superheat in the Fuel Gas Superheater 30-HS-6111 and then routed to the fuel gas manifold.

4.3.2 Fuel Gas Import Facilities

Import facilities are provided to receive pipeline fuel gas for supplementing the fuel gas produced on the FPSO as a future option and meet the total demand of FG on FPSO. The importing facilities are designed for a maximum capacity of 15 MMSCFD with a fiscal metering facility provided for accounting purposes.The arrival pressure of FG at the FPSO topsides is around 150 barg and the arrival temperature is 5°C. An Electric heater 25-HS-6112 is provided to heat the imported gas from 5°C to 65°C. This is to ensure that sufficient degree of superheat is available to prevent hydrate formation at downstream of the pressure reducing control valve which reduces the pressure from 150 to 8.5 barg.

At downstream of the pressure reducing control valve, the fuel gas import is combined with the gas from FWKO Drums, Test Separator and the compressed LP gas into a common Fuel gas header before routing to the Fuel Gas KO Drum 25-VG-6110.

To protect the downstream facilities from excess pressures due to failure of control valve, PSVs are provided at the downstream system.

4.3.3 Fuel Gas Conditioning 4.3.3.1 General

The fuel gas from the following sources is connected to the inlet header of the Fuel Gas conditioning unit.

• FWKO drums of the two trains • Test separator

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• Imported FG from the downstream of the pressure reduction control valve.

The flow rate of import gas is limited to meet the supplementary gas demand over the FG produced on the FPSO.

The Fuel gas is conditioned in the Fuel Gas conditioning unit consist of the following equipment to remove entrained liquid and provide the required amount of superheat to the FG consumers.

• Fuel Gas KO Drum • FG Filter coalescers • FG Super heater

4.3.3.2 Fuel Gas KO Drum

The Fuel Gas KO Drum 25-VG-6110 is a vertical pressure vessel designed to knock out liquid droplets from the fuel gas.

4.3.3.3 Fuel Gas Filter Coalescer

The Fuel Gas Filter Coalescers 25-FS-6113A/B are 2 x 100% units, duty / spare, designed to remove liquid and solid contaminants from the fuel gas prior to passing through the Fuel Gas Superheater 25-HS-6111. The filters are vertically oriented pressure vessels. Fuel gas entering the Filters comes from the Fuel Gas KO Drum 25-VG-6110.

The filter coalescer has two compartments. Gas enters the lower section of the vessel where it flows through vertical filter elements, any free liquids and solid particles shall be knocked out at bottom compartment. Any entrained liquids will be coalesced in the coalescing element and get collected in top compartment. The level in each compartment is maintained by separate On/Off controls. An increase in compartment level above the set point shall open the relevant on/off valve and drain to the LP Gas KO Drum 25-VG-1230. The same control configuration is applicable for the other filter coalescer.

4.3.3.4 Fuel Gas Superheater

The Fuel Gas Superheater 25-HS-6111 is an electric heater which is fully thyristor controlled, provides heat input for the fuel gas coming from the Fuel Gas Filter Coalescer. A Temperature Differential Controller (TDC) is provided to superheat the gas by 5°C at the outlet temperature of the superheater. There are conflicting requirements from the two main users of conditioned fuel gas (Power Generators and Steam Boilers). The Power Generators supplier will not accept a fuel gas supply temperature in excess of 55°C (at this temperature power generator control logic will initiate a switchover from fuel gas to liquid fuel). The Steam Boilers require 10°C superheat at the burner. Adding too much superheat in the Fuel Gas Superheater could therefore result in exceeding the maximum supply temperature constraint imposed by the Power Generators supplier. Limiting the amount of superheat added across the Fuel Gas Superheater to 5°C is sufficient to ensure maximum supply temperature limit to the Power Generators is not exceeded, while simultaneously ensuring that greater than 10°C superheat is available at the boiler burner, after letdown from fuel gas distribution system pressure to 1.5 barg (burner supply pressure).

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4.4 SEAWATER TREATMENT SYSTEM

4.4.1 GENERAL

Seawater is pumped by seawater lift pumps, filtered in coarse filters and then distributed to coolers (as cooling medium) and to the Seawater Treatment Package. Seawater Treatment Package reduces the sulphate content to eliminate the growth of sulphate reducing bacteria (SRB) in the water injection line. The outlet of the Sulphate Reduction Package is then routed to Deaerator Package to remove dissolved oxygen to 10ppb which is the specification for the Water Injection. Dissolved oxygen content at the outlet of Deaerator shall be reduced to 1 ppb when low sulphate sea water is routed to HSP power water manifold.

Hypochlorite solution (from the Hull) is supplied to the seawater lift pump suction to prevent growth of bacteria in the seawater system. Oxygen scavenger injection facilities are provided (outside package) to provide oxygen scavenger in to the deaerator sump for reducing residual oxygen content.

The seawater system consists of:

1. Seawater Lift Pumps (FF-PC-5305A/B/C)—located in Hull

2. Seawater Coarse Filtration Package (35-AY-5320) 3. Seawater Supply for Cooling duty (By BAB) 4. Seawater Treatment system (see section 5.8.2) 5. Treated Seawater Transfer Pumps (40-PC-6321A/C) 6. Seawater Heater (40-HE-6325)

Seawater design capacity at inlet to the Coarse Filters is 3500 m³/h as per Utilities Consumption Report, Refer Doc No. 21020-BAE-70000-PR-RP-7005. The effluent seawater from the seawater users is sent to the overboard. Process conditions at the seawater distribution:

Pressure: 9.5 bar g

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4.4.2 Seawater Treatment System

The Seawater Treatment Package is designed to reduce particulate matter content, sulphates and dissolved oxygen. The package contains the following equipment:

Seawater Coarse Filtration Package 35-AY5320

Seawater Fine Filtration Package (comprising Fine Filtration Unit, Backwash Pumps, Seawater Backwash/Buffer Tank, UF Neutralisation Tank)

40-AY-6321

Sulphate Reduction Feed Pumps 40-PC-6320A/B/C

Sulphate Reduction (SRU Membrane) Package 40-AY-6320A/B

Cleaning In Place (CIP) Package (comprising CIP Tank, CIP Heater, CIP Filter, CIP Pump)

40-AY-6322

Deaerator 40-CD-6323

Vacuum Package(comprising Vacuum Ejector, Separator, Vacuum Pumps)

40-AY-6323

Chemical Injection Package 35-AY-6324

Chemical Transfer Skid 35-AX-6325

4.5 SEAWATER FILTRATION AND DISTRIBUTION

4.5.1 Seawater Coarse Filtration

Seawater Coarse Filtration Package (35-AY-5320) is installed to remove bulk suspended particles from the seawater. The coarse filtration system has a backwash for removing the collected solids periodically through automatic backwashing. The filtrate is then distributed to a number of users of seawater on the topside, which include process coolers, power generation cooling, seawater treatment system, and utility stations.

4.5.2 Seawater Distribution for Cooling Duty

The filtered seawater from the outlet of the Coarse Filter is distributed to the following users as cooling medium:

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• Inert Gas Scrubber

• Miscellaneous Pumps Seals

• HSP Power Water Pump motor/lube oil cooling • Water Injection Pump motor/lube oil cooling • LP Gas Cooler (25-HE-1230)

• PW Transfer Pumps motor cooling • Steam Dump Condenser (65-HE-5722) • Utility Stations

• HSP Power Water and Water Injection Pumps VFD Cooling Circuit

4.5.3 Seawater Heater

The seawater is heated from ambient temperature to 18 o_{C before entering the sea water fine}

filtration package.

4.5.4 Seawater Fine Filtration

Seawater from the Seawater Heater (40-HE-6325) is routed to a Seawater Fine Filtration Package (40-AY-6321) which is designed to remove 99.9% of particles above 0.01 microns in diameter. The seawater filters are periodically backwashed to remove the solids accumulated. The backwash water from the filters is routed to overboard.

4.5.5 Sulphate Reduction System

Seawater from the Fine Filtration Package is pressurized using Sulphate Reduction Pumps (40-PC-6320A/B/C) to 31 bar g, and is pumped into the Sulphate Reduction Package (40-AY-6320), lowering sulphate level down to 40ppm.

To prevent chemical attack to the membranes in the Sulphate Reduction Package due to the presence of free residual chlorine, chlorine scavenger is injected upstream of the Sulphate Reduction Feed Pump 40-PC-6320A/B/C.

The Cleaning-In-Place (CIP) Package (40-AY-6322) supplies and recycles CIP chemical used in cleaning of the Seawater Fine Filtration Package (40-AY-6321) and the Sulphate Reduction Package (40-AY-6320). A number of streams from the seawater treatment system are dumped overboard when specifications are not met during start-up and shut down and in emergency instances where water levels in the units pose hazards.

4.5.6 Deaeration System

The permeate stream from the Sulphate Reduction Package enters the Deaerator Package (40-AY-6323) for lowering oxygen content. Liquid is distributed into the packed bed in the Deaerator column 40-CD-6323. A Vacuum Pump 40-PV-6323A/B is provided for efficient removal of dissolved oxygen. The Deaerated seawater containing about 50 ppb of dissolved oxygen falls into the bottom of the Deaerator column. The vacuum causes the water partial

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pressure to be reduced, resulting in the release of oxygen which is extracted from the system by the vacuum pump.

The Deaerator has a sump, into which oxygen scavenger is injected. The Oxygen scavenger is injected to reduce the Oxygen content to about 10ppb or less.

4.5.7 Chemical Transfer Skid

To prevent handling of concentrated chemicals such as Chemical Enhanced Backwash (CEB) Acid & CEB Alkali prior filling the CIP tank, a permanent facility to transfer these chemical has been provided. Chemical transfer skid consists of two transfer pumps one for Acid transfer (35-PE-6335A) and the other for Alkali transfer (35-PE-6335B) with associated tubing and valves. The skid is designed to be transportable and flexible in operation. The unit consists of 2x200L storage drums (by others), required transfer pumps and associated instruments, with flexible hoses to the skid edge to transfer the fluids.

4.6 FLARE SYSTEM

The flare system consists of a gathering header, a horizontal Flare Knock Out Drum 20-VA-1810, Flare Condensate Return Pumps, Flare Tip and a Flare Ignition Package. During normal operation only CFU vessels will vent the HC gas to the Flare System, otherwise it should have only a small purge gas flow to maintain positive pressure in the flare header hence preventing ingress of air. The table below presents the main items of equipment within the Flare system.

Flare KO Drum 20-VA-1810

Flare Drum Heater 20-HS-1810A/B

Flare Tip 20-AY-1810

Flare Ignition Package 20-AY-1811

Flare KO Drum Pumps 20-PP-1810A/B

Propane Bottle Package 20-AY-1812

4.6.1 Flare Knock Out Drum

The Flare Knock Out Drum receives fluids release from relief and blow down valves from the main high pressure processes.

The Flare Knock Out Drum is sized for the maximum continuous (and simultaneous, wherever applicable) relieving load, with considerations for both liquid and gas release. A high-high level trip (two out of three voting) in the Flare KO Drum initiates an ESD Process Shutdown. The Flare KO drum is sized in accordance with droplet size removal of 400 micron.

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Liquid separated from the gas in the Flare KO Drum is routed to the FWKO Drum for reprocessing. The gas outlet stream flows to the Flare Tip. An option to route liquids from Flare KO Drum to Slop Tank is also provided.

The Flare Knock Out Drum is provided with temperature control through two electric heaters 20-HS-1801A/B such that condensed hydrocarbons resulting from cold temperature blow down are heated up in the drum. Heating of liquids in the Flare KOD is also required to heat the liquid for pumpability as stagnant liquids will be cooled to ambient temperature, which will result in increased viscosity of any oil collected in the Flare KOD. The temperature is maintained above 45°C by the heaters installed in the Flare Knock Out Drum.

The Flare Drum Heaters 20-HS-1801A/B are electric heaters, which remain submerged in the liquid phase of the Flare KOD boot.

4.6.2 Flare KO Drum Pumps

Flare KO Drum Pumps 20-PP-1810A/B are rotary type and protected against overpressure by means of relief valves. The discharge from the pumps 20-PP-1810A/B is routed to the FWKO Drum. A connection is also provided to route flare condensate to the Slop Tank.

Each pump is designed for 10 m³/ h. The Pumps operates on level control in lead/lag configuration. The lag pump starts automatically if high level is detected in the Flare KO Drum.

4.6.3 Flare Tip and Ignition panel

The Flare Tip will be a sonic flare tip with a pressure drop of 2 bar across it at the design flow rate. Flare headers will be purged with fuel gas, with nitrogen as backup in case of loss of fuel gas. The ignition system consist of high energy (HE) electronic spark type, and a flame front generator. Propane cylinders 20-AY-1812 shall be used as back up for pilot gas when there is a drop in FG pressure and for black start.

4.7 CLOSED DRAIN SYSTEM

Closed Drains Drum 90-VA-6410

Closed Drain Heaters 90-HS-6410 A/B

Closed Drain Pumps 90-PP-6410 A/B

The Closed Drains System consists of closed drain collection headers, Closed Drains Drum 90-VA-6410, Closed Drain Drum Heaters 90-HS-6410A/B and Closed Drain Pumps 90 -PP-6410A/B.

Collection headers route maintenance drainage from individual items of equipment to the Closed Drains Drum which is floating to the flare system. The turret closed drains are also routed to the Closed Drains Drum.

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This closed drains system is completely segregated from the hazardous and non-hazardous open drainage system which is collected in the slops tank of the FPSO, in the Hull.

The liquid from the Closed Drain Drum is pumped to FWKO Drum with an option to route to the Slop Tank under level control from the Closed Drain Drum. There are 2 x 100% pumps 30-PP-6410A/B in Lead/Lag mode of operation. The level control start/stop of the pumps. The Closed Drain Vessel is provided with two Electrical Heaters 90-HS-6410A/B which are used to control the temperature of the liquid in the vessel via on/off control to meet winterization requirements.

The vapour outlet of the Closed Drain Drum is connected directly to the Flare Header, and the pressure in the closed drain vessels floats with the pressure of the flare header.

4.8 OPEN DRAIN SYSTEM

The open drains system receives drainage from hazardous and non-hazardous areas of the FPSO via separate headers.

Drain from each source is received either via a drain Box or tundish and routed to hazardous drain header or the non-hazardous drain header depending on the area classification of the drain point. Separate headers for non-hazardous and hazardous drains are provided for segregation between the systems and t o avoid migration of hazardous gases to non-hazardous area. The non-hazardous and non-non-hazardous drain headers and routed to slop tank. The turret area open drains are routed into the slop tank separately (TBC). The Heli-deck drains are routed directly overboard.

4.9 DIESEL SYSTEM

Diesel is supplied from the Hull t o continuous users, and Power Generators which use diesel to ensure the injectors are always clear. Diesel is also supplied to the day tanks of the other users i.e. Essential Power Generators, Firewater Pumps, lifeboats, cranes, etc. The steam boilers are also supplied with diesel but directly to the booster pumps. The Power Generators and the Steam Boilers are normally fired on Crude and/or Fuel Gas but can be fired with 100% diesel.

4.10 CHEMICAL INJECTION SYSTEM

Chemical injection system on Kraken FPSO includes chemicals’ storage, pumping and distribution to the process and utility systems.

4.10.1 Process Chemical Injection Storage Tanks and Pump Package

Storage Tanks and Injection Pumps are provided for the following Chemicals on the FPSO topsides:

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Topsides Chemical Injection Tanks and Pumps

Equipment Title Tag No

Scale Inhibitor Tank 35-TA-6810

HP Demulsifier Tank (Subsea) 35-TA-6815

LP Demulsifier Tank (Topside) 35-TA-6816

Anti-Foam Tank 35-TA-6825

Reverse Emulsion Breaker Tank 35-TA-6830

Flocculent Tank 35-TA-6840

Oxygen Scavenger Tank 35-TA-6865

Biocide Tank 35-TA-6870

Seawater Antifoam Tank 35-TA-6881

Methanol Tank 15-TA-6820

Oxygen Scavenger Catalyst Tank 35-TA-6880

Spare Tanks for: 35-TA-6881/6882 (2 Nos)

H2S Scavenger Asphaltene Dispersant Napthenate Inhibitor

Filter aids (Powder or liquid Foam)

LP Scale Inhibitor Injection Pumps 35-PE-6810A/B

HP Scale Inhibitor Injection Pumps 35-PE-6811A/B

HP Demulsifier Injection Pumps (Subsea) 35-PE-6815A/B LP Demulsifier Injection Pumps (Topside) 35-PE-6816A/B/C

Anti-Foam Injection Pumps 35-PE-6825A/B/C

Oxygen Scavenger Injection Pumps 35-PE-6865A/B

Reverse Emulsion Breaker Injection Pumps 35-PE-6830A/B/C

Biocide Injection Pumps 35-PE-6870A/B

Methanol Transfer Pumps 35-PE-6821

Methanol Injection Pumps 15-PE-6820A/B

Flocculent Injection Pumps 35-PE-6840A/B/C

Oxygen Scavenger Catalyst injection pumps 35-PE-6880A/B

Seawater Antifoam Injection Pumps 35-PE-6881A/B

Ashpaltene Dispersant Tank Use one of the spare Tanks

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H2S Scavenger Tank Use one of the spare Tanks

H2S Scavenger Injection Pumps Spare Pumps of connected Tank

Asphaltene Dispersant Injection Pumps Spare Pumps of connected Tank Naphthenate Inhibitor Injection Pumps Spare Pumps of connected Tank

Spare Pumps for: 35-PE-6882A/B

(2 x 100% - 1 Duty and 1 Standby)

Note: The spare Tanks and connected spare pumps can be used to inject Calcium Nitrate and Filter Aid when required.

All chemical tanks (with the exception of methanol tank and oxygen scavenger tank) operate at atmospheric conditions and are permanently installed. The tanks will be filled from tote tanks delivered by boat. Remote level indication on each tank, with low and high alarms, ensures that operations personnel are always aware of the chemicals’ storage status. The methanol storage tank is a pressurized vessel, operating at about 1.0 barg with nitrogen blanketing to prevent evaporation losses. Oxygen Scavenger tank is blanketed with nitrogen to avoid air ingress. Remote level indication is provided with low and high alarms to ensure that operators are able to monitor the methanol storage status. Methanol is kept on topsides for flooding the wellheads on shutdown and for filling into upstream side of choke valves on the production risers to prevent hydrate formation during shutdown. The methanol is supplied by tote tank located at the rear of the FPSO. Transferring methanol from tote tank to storage tanks is by pneumatically operated pumps 35-PE-6821.

The chemical injection pumps have manual stroke adjustment facility to increase or decrease the chemical injection rate remotely from the CCR. Atomizing quills are to be used to inject chemical into vapor lines.

Tank capacities are selected to allow for 12 day’s (7 days plus 5 days weather contingency) minimum capacity (in both fixed and tote tanks) and injection pumps are provided for these duties. Further chemical requirements for steam generation, SRP, Potable water, Closed Drains are not included in this table and will be defined by the Supplier.

Table below indicates location where chemicals shall be injected.

Table of Chemical Consumers and Indicative Injection location

LP Scale Inhibitor

Oil/PW Exchanger (Train A) Oil/PW Exchanger (Train B)

HSP Power Water Pumps Inlet Manifold (Topside) Water Injection Inlet Manifold (Topside)

HP Scale Inhibitor

Down hole (Upstream HSP) - Subsea LP Demulsifier – Topside

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Inlet To FWKO Drum (Train A) Inlet To FWKO Drum (Train B) Outlet of FWKO Drum (Train A) Outlet of FWKO Drum (Train B)

Inlet To Electrostatic Coalescer (Train A) Inlet To Electrostatic Coalescer (Train B) Inlet To Test Separator

HP Demulsifier – Subsea

To Turret for Subsea Production via Umbilical’s Methanol – Topside

To Topside Umbilical Termination Unit (TUTU) 1/2/3 Anti-Foam

Inlet To FWKO Drum (Train A) Inlet To FWKO Drum (Train B)

Inlet To Oil/PW Exchanger (Train A) Inlet To Oil/PW Exchanger (Train B) Inlet To Test Separator

Reverse Emulsion Breaker

Inlet To PW Treatment Hydrocyclone (Train A) Inlet To PW Treatment Hydrocyclone (Train B) Inlet To FWKO Drum (Train A)

Inlet To FWKO Drum (Train B)

Inlet To LP Separator PW Pumps Suction (Train A) Inlet To LP Separator PW Pumps Suction (Train B) Oxygen Scavenger

To treated SW transfer pump recycle line

HSP Power Water Pump Inlet Manifold (Topside) Biocide

HSP Power Water Pumps Inlet Manifold (Topside) Water Injection Inlet Manifold (Topside)

Inlet/Outlet of Deaerator Inlet to Closed Drain Drum Hazardous Open Drain Header Non Hazardous Open Drain Header Oxygen Scavenger Catalyst

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Flocculent

Inlet to CFU PW Treatment (Train A) Inlet to CFU PW Treatment (Train B) Seawater Antifoam

Inlet to Deaerator

4.11 STEAM SYSTEM

4.11.1 General

Steam is used for process heating on topsides and as the motive force for the cargo offloading pumps in the hull. Two levels of Steam are produced and utilized on the FPSO • Medium Pressure Steam at 16 barg (Boiler)

• Low pressure Steam 5.2 barg (WHRU)

(The capacity of steam produced from the Waste Heat Recovery Units is 22 Tons/h)

The users of Steam for heating on the FPSO are: TOPSIDE FACILITIES

Process heating on topsides at 5.2 barg Steam;

30-HE-1112 Oil Heater Train A

30-HE-1122 Oil Heater Train B

40-HE-6310 Water Injection Heater

40-HE-6311 HSP Power Water Heater

40-HE-6325 Seawater Heater

There are users which use steam at a lower pressure of 1.5 barg in HSP Power Water Heater, WI Heater and Seawater Heater.

MARINE SYSTEM

Storage tank heating coils/ 16 barg Steam Tank cleaning heater/

Cargo Oil Pumps

4.11.2 Steam generation system

Saturated steam is mainly generated at 16 barg from 3 x 50% fired heater boiler package (65-AY-5720A/B/C). Refer to Utility Flow Diagram (UFD), drawing number: 21020-BAE-76600-PR-DW-7060.

21020-BAE-70000-PR-RP-7003

TABLE OF CONTENTS

1.

INTRODUCTION

1.1

BACKGROUND

1.2

PROJECT OBJECTIVES

1.3

DOCUMENT SCOPE

1.4

ABBREVIATIONS

2.

OVERVIEW

2.1

GENERAL

2.2

DESIGN CAPACITIES AND SPECIFICATIONS

3.

PROCESS FACILITIES

3.1

SUB SEA PRODUCTION FACILITIES

3.2

WELL FLUID SEPARATION SYSTEM

3.3

TEST SEPARATOR

3.4

PRODUCED WATER TREATMENT SYSTEM

3.4.1

FWKO Drum Hydrocyclones (30-VJ-1610A/B & 30-VJ-1620A/B)

3.4.2

LP Separator Hydrocyclones (30-VJ-1613/1623)

3.4.3

1st & 2nd Stage Flotation Units (30-VV-1611/1612/1621/1622 A/B) and Flotation

Recycle Pumps (30-PC-1612/1622 A/B/C)

3.5

WI/HSP FINE FILTRATION PACKAGE (35-AY-6310)

3.6

SAND CLEANING PACKAGE (20-AY-6330)

3.7

HSP POWER FLUID SYSTEM

3.8

WATER INJECTION SYSTEM

4.

UTILITY SYSTEM

4.1

INSTRUMENT AIR AND UTILITY AIR SYSTEM

Equipment Title

Tag No

4.2

NITROGEN SYSTEM

4.3

FUEL GAS SYSTEM

4.4

SEAWATER TREATMENT SYSTEM

4.5

SEAWATER FILTRATION AND DISTRIBUTION

4.6

FLARE SYSTEM

4.7

CLOSED DRAIN SYSTEM

4.8

OPEN DRAIN SYSTEM

4.9

DIESEL SYSTEM

4.10

CHEMICAL INJECTION SYSTEM

4.11

STEAM SYSTEM