Material Selection and Corrosion Philosophy Report

DOC NO. FRONT-END ENGINEERING DESIGN (FEED) SERVICES FOR THIEN UNG FIXED PLATFORM

Material Selection and Corrosion Philosophy Report

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TABLE OF CONTENTS

1.0

INTRODUCTION

4

1.1

Background

4

1.2

Objectives

5

1.3

Definition Of Terms

5

1.4

Abbreviations

5

1.5

Design Life

7

1.6

Reservoir & Well Data

7

1.7

Produced Water

8

1.8

CO2 and H2S Content

9

1.9

Mercury

9

1.10

Sand

9

2.0

CORROSION MECHANISM

9

2.1

Internal Corrosion

9

2.2

External Degradation

14

3.0

MATERIAL MINIMUM TEMPERATURE LIMITATION

14

4.0

MATERIAL SELECTION FOR THIEN UNG FIXED PLATFORM FACILITIES15

4.1

Production System

15

4.2

Potable Water and Wash Water System

17

4.3

Seawater System

17

4.4

Instrument and Utility Air System

17

4.5

Waste Heat Recovery and Hot Oil System

18

4.6

Sewage System

18

4.7

Nitrogen System

18

4.8

Fuel Gas System

18

4.9

HP Flare System

18

4.10

LP Flare System

19

4.11

CPP Closed and Open Drain Systems

19

4.12

Aviation Fuel System

20

4.13

Diesel Fuel System

20

4.14

Methanol Injection System

20



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TABLE OF CONTENTS

1.0

INTRODUCTION

4

1.1

Background

4

1.2

Objectives

5

1.3

Definition Of Terms

5

1.4

Abbreviations

5

1.5

Design Life

7

1.6

Reservoir & Well Data

7

1.7

Produced Water

8

1.8

CO2 and H2S Content

9

1.9

Mercury

9

1.10

Sand

9

2.0

CORROSION MECHANISM

9

2.1

Internal Corrosion

9

2.2


14

3.0


14

4.0

MATERIAL SELECTION FOR THIEN UNG FIXED PLATFORM FACILITIES15

4.1

Production System

15

4.2

Potable Water and Wash Water System

17

4.3

Seawater System

17

4.4

Instrument and Utility Air System

17

4.5

Waste Heat Recovery and Hot Oil System

18

4.6

Sewage System

18

4.7

Nitrogen System

18

4.8

Fuel Gas System

18

4.9

HP Flare System

18

4.10

LP Flare System

19

4.11

CPP Closed and Open Drain Systems

19

4.12

Aviation Fuel System

20

4.13

Diesel Fuel System

20

4.14

Methanol Injection System

20




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4.15

Corrosion Inhibitor Injection System

20

5.0

CHEMICAL INJECTION

21

6.0

CORROSION MONITORING

22

7.0

REFERENCES

23

8.0

APPENDIX 1 – CO2 CORROSION ASSESSMENT RESULT TABLE

24

9.0

APPENDIX 2 – MATERIAL SELECTION TABLE

28


Material Selection and Corrosion Philosophy Report 1.0

INTRODUCTION

1.1

Background

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The Thien Ung field is located in the middle part of Block 04.3 in the Nam Con Son Basin, offshore the Socialist Republic of Vietnam, approximately 15 km of Dai Hung field and approximately 270 km southeast of Vung Tau. The block 04.3 covers an area of approximately 2600 km2. The Thien Ung field is including its 2 structural part. Thien Ung structure discovery was made in 2004 with the 04.3-TU-1X well. Two subsequent appraisal wells (04.3-TU-2X and 04.3-TU-3X), drilled and tested respectively, delineated the field. Location of Thien Ung field is shown in Figure 1.1 below. Figure 1.1: Thien Ung Reservoir Location

A Pre-FEED study was carried out to select the most viable platform configuration. The configuration of two separate platforms, namely Fixed Drilling Platform (FDP) and Central Processing Platform (CPP) bridge linked were selected for FEED. Drilling will be carried out by self contained Modular Drilling Rig located at FDP.



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Objectives This document defines the material selection basis and corrosion protection philosophy for Thien Ung field development. It includes the minimum recommendations for the material selection for the Fixed Drilling Platform (FDP) and Central Processing Platform (CPP) topsides.

Materials specified in the current design at this FEED stage are acceptable but relatively conservative. A material selection study has been done to optimize the materials utilization. Materials recommended in Although the piping in this system is not NACE specified due to the low design pressure, it is recommended that the vessels to be NACE specified. this report for certain systems are less conservative as compared to the materials in the current design and to be considered and further study during the next phase of Detail Engineering Design. A brief corrosion monitoring philosophy is also included. Materials are recommended based on the intended service and operation constraints as per the H&MB. Any changes in the operating conditions during next project stage may require review and modification of the selected materials. 1.3

Definition Of Terms Within this document the following definitions shall apply:

1.4

COMPANY

The party which initiates the project and ultimately pays for its design and construction and owns the facilities. Here the COMPANY is Vietsovpetro JV (referred to as VSP).

CONTRACTOR

The party which carries out all or part of the design, engineering, procurement, construction and commissioning of the project.

VENDOR

The party which the order or contract of supply of the equipment/package or services is placed.

Shall

Refers to mandatory requirement

Should

Refers to a recommendation

Abbreviations bbl/d

Barrel per day

BLC

Bottom line corrosion

CA

Corrosion allowance

CAPEX

Capital expenses

CC

Corrosion coupon

CO2

Carbon dioxide


Material Selection and Corrosion Philosophy Report CPP

Central Processing Platform

Cr

Chromium

CRA

Corrosion resistance alloy

Cru

Corrosion rate

CS

Carbon steel

CSSC

Chloride Stress Corrosion Cracking

D

Diameter

DegC

Degrees celcius

DSS

Duplex stainless steel

ERP

Electrical resistance probe

FDP

Fixed Drilling Platform

FEED

Front end engineering design

FPSO

Floating production storage and offloading

FWHP

Flowing wellhead pressure

FWHT

Flowing wellhead temperature

GRP

Glass reinforced platics

H&MB

Heat and material balance

HHP

High high pressure

HIC

Hydrogen Induced Cracking

HP

High pressure

HSE

Health, Safety and Environment

H2S

Hydrogen sulphide

KO

Knocked-out

LP

Low pressure

LTCS

Low temperature carbon steel

m/s

Meter per second

MIC

Microbiologically influenced corrosion

mm/yr

Millimetre per year

MMSCFD

Million standard cubic feet per day

MP

Medium pressure

NNF

Normally no flow

OPEX

Operation expenses

PC

Potential corrosivity

ppm

Parts per million

SDSS

Super duplex stainless steel

SC

Sampling connection

SRB

Sulfate reducing bacteria

SS

Stainless steel

SWC

Step Wise Cracking

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THPS

Tetrakis hydroxymethyl phosphonium sulphate

TLC

Top of line

TRB

Thiosulphate reducing bacteria

TSA

Thermally Sprayed Aluminum

WCR

Water condensation rate

WHP

Wellhead platform

WHSIP

Wellhead shut in pressure


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Design Life The facilities shall be design for a service life of 25 years [1].

1.6

Reservoir & Well Data The following key reservoir data for Thien Ung 04-3X block as given in document 5691-GEN-PRRPT-9901 shall be used to achieve the water analysis consistency. Table 1.0: Key Reservoir Data for Thien Ung 04-3X Block [1]. Parameter

Value

Reservoir Pressure (barg) Reservoir Temperature (°C)

257 – 504 (254 – 497 atm) 112 - 153

The full well stream compositions are based on the well working pressure of 410 barg and temperature of 148°C [1]. The full well stream compositions that are confirmed by VSP to be used for process design are given in the following table. The compositions are based on year six production [1]. Table 1.1: Full Well Stream Composition (Dry Basis) [1]. Component

Full Well Stream (mole%)

H2S

0.000

CO2

9.597

N2

0.383

C1

70.345

C2

7.823

C3

4.553

iC4

1.120

nC4

1.326

iC5

0.545

nC5

0.382


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1.7

Component

Full Well Stream (mole%)

Pseudo C6 Pseudo C7 Pseudo C8 Pseudo C9 Pseudo C10 Pseudo C11 Pseudo C12 Pseudo C13 Pseudo C14 Pseudo C15 Pseudo C16 Pseudo C17 Pseudo C18 Pseudo C19 Pseudo C20+ Total

0.777 0.838 0.580 0.296 0.243 0.146 0.127 0.104 0.078 0.065 0.043 0.022 0.019 0.018 0.570 100


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Produced Water Water analysis from Thien Ung 04-3X block field given by VSP is summarized in the following table: Table 1.2: Water Analysis Constituents (taken from excel spreadsheet Water_Analysis_Bang_1.6.3) Cations Na+ K+ Ca++ Mg++ Fe++ Sr++ Ba++ Anions ClHCO3CO3- AcSO4--

meq/L 489.91 2307 1525 137 15.25 meq/L 626.76 769 0 13.24

mg/L 11268 2307 1525 137 15.25 mg/L 22250 769 0 635.4

As tabulated in the table above, no acet ic acid content is reported. For corr osion assessment with Corplus software, recommended default acetic acid value shall be used is 59mg/L.




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CO2 and H2S Content CO 2 in vapor phase composition value of each stream given by Process group shall be used for corrosion assessment by Corplus. There is no significant H 2S detected in any of the well tests. However for design purpose, the design maximum H 2S for combined production will be taken as 20 ppmv [1].

1.9

Mercury No significant mercury content was detected in any of the well test to date [1].

1.10

Sand According to Process and Utility Design Basis, 569 1-GEN-PR-RPT-9901, studies have indicated a risk for low levels of solids production from wells during later years of field life. The sand control philosophy will be to manage sand down-hole through the use of gravel packs or screens. There is a small risk that sand may accumulate in the production separators during later years of field life. These vessels should therefore be equipped with appropriate internal sand flushing from the vessels during later years of field life. Peak predicted sand loading is less than 130 litres/MMscm (16 -17 lb/MMscf) [1]. As per VSP clarification, influence of sand on abrasive damage is low where carrying out of sand from gas wells is always low especially if sand traps use in wells [7].

2.0

CORROSION MECHANISM

2.1

Internal Corrosion The most likely degradation mechanisms that can cause internal damage to hydrocarbon systems are as follow: CO2 Corrosion; H2S Cracking; Microbiologically Influenced Corrosion (MIC); and Galvanic Corrosion. Erosion Corrosion

2.1.1

CO2 Corrosion CO2 corrosion constitutes the major cause of metal loss of carbon steel components of which surface exposed to water. Any water in contact with vapor phase CO 2 will dissolve the CO2 and form weak carbonic acid; which may lower the pH and consequently promote general corrosion and/ pitting corrosion. Although it is a weak acid, carbonic acid is highly corrosive because the cathodic part of the corrosion reaction does not need H+ as with normal acid corrosion but instead involves direct reduction of undissociated acid.



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Parameters affecting CO2 corrosion include: Water chemistry, organics acids, pH, water wetting, hydrocarbon characteristics and phase ratios; CO2 and H2S content (and possible oxygen contaminants); Temperature and pressure; Steel surface including corrosion film morphology; Fluid dynamics; and Steel chemistry.

Water Wetting Water in the hydrocarbon mixture can be entrapped completely in the oil emulsion or it can be present as a separate water phase. In order for corrosion to occur; water must wet the steel surface. The presence of water phase depends on: Water cut; Flow condition (velocity, flow regime, surface condition); and Light or heavy hydrocarbon (water separation is easier in light hydrocarbon).

Effect Of Condensation During hydrocarbon gas transportation, condensation of water vapor may occur on the internal pipe wall due to some cooling effects of the fluid. If water is condensing, the water will be saturated with the acid gas CO2 and acetic acid with pH typically <4. High condensation rate could subsequently lead to high corrosion rates due to low pH of purely condensing water. If the condensation rate is slow, the water film will be saturated with corrosion product leading to a high pH and the formation of possibly protective iron carbonate film. CO2 Corrosion Model CO2 corrosion assessment of this project was performed using Corplus V21 Corrosion Evaluation Tool. Refer Corplus evaluation result in Appendix 1. Corplus is a CO 2 corrosion prediction tool for Carbon steel materials. It also gives erosion corrosion conditions and sour services conditions based on MR0175/ISO15156 severity diagram. This model was developed by the Total Company based on the previous Cormed model from Elf and Lipucor model from Total and verified by laboratory testing conducted in a Norwegian Institute IFE under a JIP project (Joint Industrial Programs) where other operators were involved including Statoil, Norsk Hydro, Shell etc. The main characteristics of the two models at the origin were the data base which was extracted from many feedback experiences of fields of production. Corplus is mainly a pH and corrosion prediction tool for oil and gas production facilities. It contains three main prediction modules: pH calculations




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corrosion prediction, erosion-corrosion in sweet conditions sour service prediction The Corplus model corrosion evaluation is based on past experiences and wide field data base. It combines/improves capabilities of previous models from Cormed (ELF), Lipucor (Total) and others like KFD2 JIP project. The CO2 corrosiveness which is the most accurate predictive parameter provided Corplus can be defined through different categories as indicated in the table below: Table 1.3: Classification of CO 2 Corrosiveness according to CORPLUS CO2 Corrosiveness/Corrosion likelihood

Typical corrosion rate -> CO2 corrosiveness

Approximate lifetime vs design life (assuming no preventive action) * ->CO2 Corrosion likelihood

Practical failure likelihood

Very low

< 0.1 mm/yr

System will last much longer than required with no failures, without any preventive action

None

Low

0.1 – 0.3 mm/yr

System should reach its design life without a failure with available corrosion allowances, not requiring any complementary preventive action

Negligible

Medium

0.3 to 1 mm/yr

System should reach 50% of its design life before a failure occurs, if no preventive action is undertaken

Likely but delayed

High

1 to 3 mm/yr

A failure will occur after 25% of its design life, if no preventive action is undertaken

Very likely within a few years

Very high

> 3- 5 mm/yr

The system will not even resist ¼ of its design life, if no preventive action is undertaken

Certain and soon

* : Indicative only, since limits are dependent on wall thickness and design life. 10- 15 mm and 20- 25 yrs considered as default values. Corrosion rate: This quantitative parameter is aimed at characterizing the corrosion rate of the whole fluid (including oil and gas) to corrode the steel surface within the given calculation conditions. It is determined from quantitative criteria considering pH, PC, corrective factors for temperature, glycol, oil/ water wetting. On the other hand, no complementary qualitative parameters referring to pitting tendencies and protectivity by corrosion products are considered, as for the complete CO2 corrosiveness. CO2 corrosiveness: It is the actual capacity of the water, if any, to corrode the steel surface within the given calculating conditions. When compared to the quantitative corrosion rate calculation described here above, this parameter: Include additional qualitative criteria determined from a detailed review of field experience, about practical pitting tendency or protectivity by corrosion products Does not include any possible beneficial effect of oil wetting, so it is only related to the corrosiveness of the produced water Is provided in qualitative severity categories as indicated in the table The lower of these 2 parameters must be used.


Material Selection and Corrosion Philosophy Report 2.1.2


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Microbiologically Induced Corrosion (MIC) Microbiologically Induced Corrosion (MIC) is a mode of corrosion incorporating microbes like SRB (Sulphate Reducing Bacteria) or TRB (Thiosulphate Reducing Bacteria) that react and form H 2S which cause corrosion. The most likely sources are from drilling campaigns, well service activities, precommissioning or hydrotest activities, sump systems, vessel cleaning or maintenance operations. The MIC normally occurs under deposits, in low velocity flow or stagnant water. Activities like hydrotesting, vessel cleaning or any other activities which allow ingress of water into the equipments or piping must only use treated (sea) water. MIC could be monitored by doing sampling, however this method will assess bacteria of mostly the mobile (planktonic) ones. It is recommended to do sampling at the inlet of the pipelines and at the downstream of the open caisson and closed drain drum. It is crucial to monitor the sessile (surface adhering) bacteria as it will adhere to the surface and has chances to reduce the sulphur to acid and eventually corrodes the surface. One of the monitoring methods is by placing bioprobes. If bacteria are detected then biocides should be used to mitigate the bacteria growth. Common biocides used are glutaraldehyde, quaternary ammonium or THPS. For treatment of vessels, injection of certain amount of biocide into the vessel is necessary after each transfer of effluent to the production facilities. When the vessel is full of liquid, at least 200ppm concentration of the active product is required. Refer to the options below for the bacteria control of pipelines which has been proven to be sufficient: Option 1 Weekly pigging, inject Biocide for 2 hours, 3 times per week. Option 2 8 hours of continuous injection on weekly basis immediately after pig launching. Normal Operation: - 500ppm Upset Condition: - 1000ppm Note: Injection rate given above is a practice of an operator in Sarawak oil and gas field which may be a basis for Thien Ung Fixed Platform FEED. The injection rates have been proven to be sufficient for Sarawak field but the concentration will vary according to projects. Injection rates for Thien Ung will be confirmed prior to vendor’s discussion. The use of any biocides, oxygen scavengers or combination chemicals should be qualified to assess the suitability prior to use.

2.1.3

Sand Erosion For cases where sand is expected, excessive sand production may cause sand erosion especially at components that experience sudden directional change (ex. elbow) or flow restriction (ex choke and valve). Important factors that determine sand erosion sand erosion rate including sand production rate, fluid properties (velocity, viscosity, and density) and sand characteristics (size, hardness, shape). The sand control philosophy of Thien Ung platforms will be to manage sand down-hole through the use of gravel packs or screens. Due to the risk that sand may accumulate in the production separators during later years of field life, these vessels should therefore be equipped with



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appropriate internal sand flushing and nozzles to enable sand handling and flushing from the vessels during later years of field life. As per VSP clarification, influence of sand on abrasive damage is low where carrying out of sand from gas wells is always low especially if sand traps use in wells [7]. Other philosophy being implemented by other projects is to have a non-intrusive sand detector on each flowline. If sand is detected, production from the well will be cut back or the well will be shutin manually or remotely and worked over to eliminate sand production. It is recommended that the risk of erosion should be undertaken at susceptible areas e.g bend, choke valves. 2.1.4

Dissimilar Material There is a risk of galvanic corrosion when connecting CRA and carbon steel pipes with existence of corrosive free electrolyte (ex: water) flowing through the joints. In order to minimize galvanic corrosion at these joints on wet service process piping, the following rules shall be applied: 1) A flange connection shall be applied; 2) The whole CS flange surface including the ring groove or gasket surface shall be cladded with suitable CRA like SS316L; 3) CRA ring joint or gasket shall be used between CRA and the cladded CS side; and 4) The connection to be located as far as possible on a vertical position to avoid trapped water at the joints. This solution applies to wet piping with corrosive fluid and it is not needed for dry gas, oil piping or non corrosive service.

2.1.5

Internal Coating of Vessels/ Tanks In order to ensure an internal corrosion protection, carbon steel vessels or tanks shall be internally coated when continuous water phase can be present. This is particularly the case of separators, drain sump tanks, water tanks and crude oil/ condensate storage tanks. Depending on the working condition and also the size of the tank, the coating specification will be finalized on case by case basis whether to be coated fully or only at the bottom part where water accumulation may occur. It is recommended that the coating is associated with cathodic protection provided by sacrificial anodes as precaution in case of any imperfection of the applied coating. For the internal coating applied with GRP, in the range of 1 to 2mm thickness, sacrificial anodes can be avoided as far as the quality of the applied coating is high. Common types of sacrificial anodes are Zn and Al anode depending on the service condition. Remarks: The anode consumption will be verified during the internal inspection. The sacrificial anodes will only be consumed if there is any imperfection of the applied protective coating.


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2.2.1

External Chloride Stress Corrosion Cracking (CSCC)


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CSCC is a failure mode caused by the combined effect of tensile stress and corrosive environment (presence of chloride ion, oxygen and high temperature). Austenitic stainless steel is susceptible to external CSCC at temperature above 60°C while duplex stainless steel (DSS) above 100°C. Austenitic stainless steel piping and equipment shall be externally painted if the operating temperature is higher than 60°C. For DSS, painting shall be applied if operating temperature higher than 100°C. Painting to be applied shall be qualified to assess the suitability prior to use. The minimum acceptable austenitic SS is type 316/316L. The 316 materials exposed to marine environment, shall have a minimum Mo content of 2.5%. This concerns mainly the piping and tubing materials. For tubing connected to the main process lines & vessels that warmer than 60°C, and piping of diameter less than 2”, the stainless steel mater ial shall be SS904L or 6Mo and no painting is required. 2.2.2

Piping Support The piping supports shall be designed to avoid possible crevice corrosion of stainless steel at the support locations, due to aqueous chloride environment. Direct supporting of non-painted SS piping on either CS supports or even a plastic or elastomeric shoe is not recommended because of high risk of crevice corrosion. Dedicated supporting systems must be applied on SS piping. However, according to VSP experience stainless steel is not required for supporting of pipes, carbon steel with plastic cover for prevention electrochemical and slot-hole corrosion is admissible [7]. The recommendation is to apply local glass flake coating on the SS pipes (1mm thick) at the level of the supports. Another system could consist on stratified shell composed of laminated epoxy resin reinforced with fiber glass and glued to the pipe and finally, an elastomer sheet will be placed between the SS pipe and the support.

3.0


The material selection must take into account the minimum operating temperature and that predicted during blowdown to avoid brittle fracture. Minimum service temperatures of various materials are given as follow: Metal Carbon Steel (Note 1) LTCS Austenitic Stainless Steel (i.e SS316, SS321…) Duplex Stainless Steel 22% Cr 25% Cr Nickel Base Alloys

Minimum Design Temperature (degC) 0 -46 -105 -196

Impact Tested

-50 -50 -196

Yes Yes No

No Yes No Yes


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Note 1: Carbon steel may be used in piping systems with a minimum design temperature down to -29degC if the nominal wall thickness is less than 12.7mm, or as specified in ASME B31.3. For lower design temperatures down to -46degC, impact testing shall be performed. 4.0

MATERIAL SELECTION FOR THIEN UNG FIXED PLATFORM FACILITIES

The overall approach to material selection for piping and equipments was initially to evaluate the internal corrosivity of the fluids with respect to utilization of carbon steel. Corrosion resistance alloys (CRA) or stainless steels shall be recommended for the cases where carbon steel with corrosion allowance and corrosion inhibitor are still not sufficient to withstand the corrosion throughout the design life. In cases where SS316L material being used at above 60°C and DSS at above 100°C, painting shall be applied and painting shall be qualified to assess the suitability to be used at certain design temperature. Material recommendation is based on non-insulated piping system basis. If any piping to be insulated, materials recommendation to be further evaluated during detail design engineering as the insulation may have implications on the material selection. 4.1

NACE Requirements for Sour Services The requirements outlined in the NACE MR0175/ISO 15156 shall be followed if the particular streams are categorized in “Sour Service”. Generally, NACE requirement involves the control of chemical composition, heat treatment, mechanical properties, hardness, environmental and materials limits. The following covers some of the important requirements for the carbon steel & low alloys steels and CRA according to NACE MR0175/ISO 15156. Materials CS and LTCS

SS316L DSS

Additional Requirement for NACE as per NACE MR0175/ISO 15156 1) Carbon Equivalent, CE = 0.43 MAX 2) Hardness = 250HV 3) HIC/SWC TM0284 testing plate (qualification) 1) All components to be solution annealed and water quenched. 2) Hardness = 28 HRC max. 1) All components to be solution annealed and water quenched. 2) Ferrite content = 35 – 65%

CRA components e.g. 316SS and DSS purchased from reputable manufacturers and manufactured in accordance with the appropriate ASTM product standard e.g. ASTM A240, A182 etc should be automatically compliant with the requirements of NACE MR0175 though this should be confirmed prior to purchase. The additional requirements required for CS and LTCS seamless and forged components to comply with NACE MR0175, i.e. C.E and hardness limit if purchased from reputable manufacturers and manufactured in accordance with the appropriate ASTM product standard should be compliant with requirements of NACE MR0175, though this should be confirmed prior to purchase. In the case of CS and LTCS components made from plates HIC/SWC qualification testing of plate is required in accordance TM0284. The cost of the qualification testing is dependent upon the quantity of plate and the prevailing market conditions.



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Production System The materials selection for the production system is based upon the production streams being oxygen free. There is a proposal to route fluids from the LP flare KO drum/ open drain caisson to the production separator. This will result in the possible introduction of seawater and oxygen into the production system. This would have major implications on the materials of construction proposed below and therefore it is recommended that the proposal for routing to the separator should not be adopted. Based on the Corplus corrosion evaluation results in Appendix 1, the CO 2 corrosiveness for the streams of FDP facilities are classified as “Very High”. “Very High” corrosiveness corresponds to the typical corrosion rate relatively beyond 3mm/yr. These streams include the flowline upstream and downstream the choke valve going to the test separator (Stream 1A, 1B) and to the production cooler on CPP (Stream 2) and also streams downstream the test separator (Stream 1C - 1F). From the corrosion assessments, it is indicated that the high corrosion allowance values is beyond CS sufficiency. Since CS with 95% efficiency inhibition is insufficient to withstand the corrosiveness and also highly unlikely to be achieved on a production piping system, CRA material is recommended. DSS NACE is recommended for the FDP piping streams due to the high corrosiveness and temperature. However, CS with SS316L cladded shall be recommended for the FDP closed drain vessel due to the low design pressure where SS316L utilization is still within the limit as per NACE MR0175/ISO15616-3. Material recommendation for FDP and CPP facilities are summarized in Appendix 2. Piping in the production cooler and the production separator system (Stream 102, 103) are recommended to be in DSS NACE material. Recommendation is made based on the corrosiveness and also by considering the high pressure piping. Due to the high pressure, material will require higher mechanical strength to resist the pressure and this condition could be achieved by increasing the pipe wall thickness. DSS has a higher mechanical strength compared to SS316L and therefore will achieve a certain strength at a lower wall thickness as compared to SS316L. DSS with lower wall thickness requirement will probably cost almost the same or maybe slightly higher than SS316L with a higher wall thickness. The selection may have a slightly higher CAPEX but the OPEX is reduced and also a higher mechanical strength and corrosion resistance can be achieved. The gas line downstream the production separator going to the TEG contactor (Stream 104, 109, 110) which contains non-dehydrated gas is recommended to be in DSS NACE material. Although no free water is reported in the H&MB [2], but in reality water condensation on the pipe wall is expected due to the high temperature difference between the internal pipe temperature and the external temperature. For a 25 years design life facility, this condition may be a detrimental issue in a long run and therefore DSS NACE is recommended. However, gas lines downstream the TEG contactor (Stream 112, 128, 129, 140, 108,113, 107) are recommended to be in LTCS with 3mm CA NACE as the gas is dehydrated and no corrosion is expected. Dehydrated gas lines in the export gas custody metering system (Stream 141, 115, 116, 117) up to the production launcher are recommended to be in LTCS with 3mm CA NACE. As requested by the Process Group, the H2S partial pressure shall be calculated based on the design pressure instead of the operating pressure. The calculations show that the H 2S partial pressure for this system is beyond the sweet service limitation of 0.003bar. The condensate lines downstream the production separator up to the condensate dehydrator (Stream 105, 119, 120, 121, 124) are recommended to be in DSS NACE. The corrosiveness of



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these lines is classified as “Very High” by Corplus. However, material selection of LTCS with 3mm CA NACE is recommended for the dehydrated condensate lines downstream the condensate dehydrator up to the launcher (Stream 125, 134, 135, 126, 127, 142, 118). In the condensate dehydrator, the dehydrated gas supplied from the TEG dehydration system will absorb the moisture from the condensate producing dehydrated condensate. The moisture will be carried to the rewetted stripping gas compression system and will be sent back to the TEG dehydration system. The piping which carries the moisture (Stream 130, 131 133) is recommended to be in DSS NACE as the wet vapour may reach its dew point and condensed on the pipe wall. LTCS with 3mm CA NACE is recommended for the whole Gas Compression System (Stream 143A/B, 136A/B, 138A/B, and 139A/B). Alternative of SS316L NACE is recommended in case if there will be any condensation occurs due to the high temperature range between the upstream and downstream of the gas compressor after cooler. According to the Process group, there should not be any condensation since the gas is dehydrated. 4.3

Potable Water and Wash Water System Piping upstream the potable water maker package which carries seawater shall be in copper nickel material or in GRP as alternative. Potable water piping shall be SS316L while wash water system piping shall be in CS with 3mm CA. Potable water storage tank and pressurized potable water vessel shall be in CS with 3mm CA and internally epoxy coated or in GRP material. The coating shall be approved by HSE due to the potable water service. As alternative, CS with SS316L cladded or solid SS316L shall be recommended for the potable water storage tank and the vessel. Selection of the alternative shall depend on the tank and vessel dimension. The wash water tank shall be in CS with 3mm CA and internally epoxy coated. Potable water pumps shall be in SS316 while wash water pumps shall be in CS. For the potable water filter, the vessel and internals shall be in SS316L.

4.4

Seawater System Piping for the whole seawater system shall be in Cu-Ni and GRP as alternative material. Seawater lift caisson shall be made from CS with 3mm CA internally and externally with glass flake epoxy coating on both internal and external sides. Additional protection shall be applied by placing internal sacrificial anodes at the bottom part of the open drain caisson. The seawater lift pumps shall be from Super Duplex Stainless Steel (SDSS) or Nickel Aluminum Bronze as alternative. Seawater strainer shall be made of SDSS. VSP clarifies that pipes with internal anticorrosive coatings, protective inserts are necessary for welded seams [7].

4.5

Instrument and Utility Air System The instrument and utility air system shall be in SS316L stainless steel or galvanized CS as alternative material. Cleanliness concern for instrument air system is detrimental to avoid rust particles that may plug the gas distribution header. Instrument gas contaminated with particles will cause defaults and may damage the equipments. It has been clarified by VSP that SS316L stainless steel is necessary for air before its cleaning but it is possible and preferable to apply galvanized steel pipes after air cleaning [7], [8].



REV. NO.


0 Page 18 of 33

Wet air and instrument air receiver can be in CS with 3mm CA with epoxy internal coating and CS with SS316L cladded or solid SS316L as alternative. Selection of CS with SS316L cladded or solid SS316L shall depend on the dimension of the vessel. We highly recommend CS with SS316L cladded or solid SS316L to avoid corrosion in case if the dryers do not function well causing the presence of water vapor in the line. 4.6

Waste Heat Recovery and Hot Oil System CS with 3mm CA is recommended for the piping of above system. The hot oil expansion vessels and hot oil trim cooler shall be in CS with 3mm CA. Hot oil circulation pumps and the hot oil side stream filter shall be in CS.

4.7

Sewage System Sewage system piping shall be in GRP. The sewage water disposal caisson shall be made from CS with 3mm CA internally and externally with glass flake epoxy coating on both internal and external sides. Additional protection shall be applied by placing internal sacrificial anodes at the bottom part of the caisson.

4.8

Nitrogen System The piping for the nitrogen system shall be in CS with 3mm CA. The nitrogen receiver shall be in CS with 3mm CA with internal coating.

4.9

Fuel Gas System Piping for fuel gas system shall be in CS with 3mm CA NACE. For piping with lower design temperature below 0deg°C, LTCS with 3mm CA NACE shall be required. Piping from the filter to the turbine shall be in SS316L [8].

4.10

HP Flare System Gases and liquid released from the HP equipment sources is routed to the HP flare KO drum via HP flare header. Stainless steel LT is recommended for the HP flare header due to the very low temperature. The painting system to be applied shall be qualified to assess the suitability to be used at specific design temperature. As alternative, 6Mo is recommended for the header. HP flare release separated from the drum is sent to the HP flare tip for disposal by combustion. The same material as the header is recommended for this gas line going to the HP flare tip. The flare tip shall be in SS310 for temperature exposed to oxidation/ scaling while SS316L minimum for lower temperature zones. The material selection for the flare tip shall be confirmed with the vendor. Liquid separated in the HP flare KO drum is recovered to production separator by the HP flare KO drum booster pumps and HP flare KO drum pumps. Liquid discharge outlet up to the shut down valve (SDV) shall be stainless steel LT with painting due to the KO drum design conditions. As alternative, 6Mo is recommended. Piping downstream the SDV to the HP flare KO drum pumps



REV. NO.


0 Page 19 of 33

shall be in LTCS 6mm CA with coating and regular basis inspection. As alternative, the piping is recommended to be in DSS to ensure the uniformity of material selection with the production line. Piping downstream the HP flare KO drum pumps going to the production separator shall be in DSS. The pumps shall be in SS316. HP flare KO drum is recommended to be in solid SS316L coated with TSA (thermally sprayed aluminum) externally. 6Mo is recommended as the alternative. The materials are recommended by assuming no oxygenated seawater will be recycled back to the production separator. Introduction of seawater and oxygen into the production system will have major implications on the materials of construction proposed. Besides acting as the hold up drum for HP flare gases and liquid, the HP flare drum also functions as process liquid drains drum. The process drains are routed to HP flare KO drum through the continuous process drains header. LTCS 6mm CA with coating and regular basis inspection shall be recommended as the header. Although the piping in this system is not NACE specified due to the low design pressure, it is recommended that the vessels to be NACE specified. 4.11

LP Flare System The LP flare will take continuous hydrocarbon emissions and emergency release from the LP equipment sources. The hydrocarbon release is routed to the LP flare KO drum via the LP flare header. The header shall be in LTCS 6mm CA with coating and regular basis inspection. Alternative shall be SS316L. LP flare gases separated from the drum are sent to LP flare tip for disposal by combustion and the piping shall be in the same material as the header. The flare tip shall be in SS310 for temperature exposed to oxidation or scaling while SS316L minimum for lower temperature zones. The material selection for the flare tip shall be confirmed with the vendor. Liquid collected in the LP flare KO drum is recovered to HP flare KO Drum by the LP flare transfer pumps. The piping is recommended to be in LTCS 6mm CA with coating and regular basis inspection. Alternative shall be SS316L. The pumps shall be in CS. LP flare KO drum is recommended to be in CS with 6mm CA with Phenolic coating shall be recommended but the Phenolic coating shall be qualified and approved during detail engineering stage for the intended services. The alternative shall be CS with SS316L cladded. Although the piping in this system is not NACE specified due to the low design pressure, it is recommended that the vessels to be NACE specified.

4.12

CPP Closed and Open Drain Systems Closed drain system shall be designed to collect only the maintenance drains from the pressurized process and utility systems on CPP and not designed to collect intermittent or continuous process drains from the topsides. Liquid collected in the CPP closed drain vessel is pumped by the closed drain vessel pumps to the HP flare KO drum and the gas is routed to the LP flare header. The liquid piping is recommended to be in CS 6mm CA with coating and regular basis inspection. Alternative shall be SS316L. The gas line shall be in CS with 3mm CA. The



REV. NO.


0 Page 20 of 33

pumps shall be in CS with 13Cr impeller and SS316 as the alternative. The caisson shall be made from CS with 3mm CA internally and externally with glass flake epoxy coating on both internal and external sides. Additional protection shall be applied by placing internal sacrificial anodes at the bottom part of the caisson. Residual hydrocarbon with traces of oxygen contained seawater will be pumped out from the caisson and therefore the fluid will be very corrosive. CS 6mm CA with coating is recommended and the piping shall be monitored by inspection program. Usage of CRA material without inspection is possible for this line if the design temperature to be reduced during the detail design engineering stage. 25Cr Super Duplex shall be further evaluated as the option. If the design temperature to be maintained, the options could be Titanium or Nickel alloys where no painting and inspection program are required. The pump shall be in SDSS or Ni Al-Br as an alternative. Although the piping in this system is not NACE specified due to the low design pressure, it is recommended that the vessels to be NACE specified. Remarks: The materials selection for the production system is based upon the production streams being oxygen free. There is a proposal to route fluids from the open drain caisson to HP flare KO drum and going back to the production separator. This will result in the possible introduction of seawater and oxygen into the production system. This would have major implications on the materials of construction proposed and therefore it is recommended that the proposal should not be adopted. 4.13

Aviation Fuel System SS316L is recommended for the aviation fuel system piping.

4.14

Diesel Fuel System Diesel piping shall be in CS with 3mm CA. The raw diesel coarse filter and the diesel filter coalescers shall be in CS with 3mm CA and SS316L internal parts. Diesel storage tank shall be in CS with 3mm CA. CS shall be the recommendation for the diesel transfer pumps.

4.15

Methanol Injection System Material recommended for the methanol injection system is CS with 3mm CA. Methanol storage tank shall be in CS with 3mm CA.

4.16

Corrosion Inhibitor Injection System Materials for corrosion inhibitors handling will be in SS316L to keep the chemicals clean. However, based on VSP’s experience, GRP has been successfully applied for many years [7].



REV. NO.


0 Page 21 of 33

CHEMICAL INJECTION

Chemical inhibitor injection is required to give protection to carbon steel piping. Corrosion inhibitor availability measured by monitoring should be 95% or above. Chemical inhibitor injection is not required for CRA piping. As for Thien Ung facilities, it has been studied that even with 95% corrosion inhibitor availability, carbon steel with corrosion allowance is still not sufficient to withstand the corrosiveness of this field. Therefore, CRA piping is recommended mostly and corrosion inhibitor injection is not required for most of the piping system. However, provision for corrosion inhibitor injection shall be provided for the pipeline. Corrosion inhibitor shall be injected atleast 10 pipe diameters downstream the starting point of the carbon steel pipeline. The 10(D) length is required to accommodate proper mixing of the corrosion inhibitor with the production gas/ condensate. For this project, it is identified that the best location for the CI injection point shall be upstream the gas/ condensate mixer. Provision of biocide and oxygen scavenger or multipurpose chemical injection should be considered for the HP flare KO drum since it will collect fluids from the open drain caisson. The treatment is necessary in case if the open drain caisson collects corrosive fluids containing oxygen and seawater where there will be a risk of MIC. In the case where bacteria exists, these bacteria will then be propagated throughout the downstream of caisson to the HP flare KO drum where residual hydrocarbon will be routed back to the HP flare KO drum and subsequently to the production separator . Again it should be recognized that such a production scenario would have major implications on the materials of construction recommended in this report. Table 5.0 : Requirements of Chemical Treatment of Thien Ung facilities. Chemical Corrosion Inhibitor

Location To be injected atleast 10(D) downstream the pipeline inlet to allow proper mixing between the inhibitor and the product.

O2 Scavenger + Biocide

Provision for multifunctional product injection at the HP flare KO drum

Comments For this project, it is identified that the best location for the CI injection point shall be upstream the gas/ condensate mixer. To prevent bacteria growth.


REV. NO.



0 Page 22 of 33

CORROSION MONITORING

Corrosion monitoring devices shall be installed to monitor the corrosivity, chemical treatment efficiency and bacteria activity. Access fittings (standard 2”) should be provided for the use of both ER probe and corrosion coupon (CC) as a minimum. Normally access fitting is located at 6 o’clock position. Corrosion monitoring devices shall be retrievable where a minimum clearance of 2m below the pipe is required for retrieving operation. For cases where the pipeline is in carbon steel, ER probe, CC and SC to be installed at the pipeline for monitoring. Coupon and probe shall be distant by 1m minimum. These devices shall be located at the pipeline inlet upstream the barred tee. Fluid coming from the HP flare KO drum will be monitored to trace any bacteria presence. Liquid will be monitored by installing SC at the HP flare KO drum liquid outlet. Monitoring is necessary because the liquid will be routed back to the production line. Other monitoring devices of the facility are summarized in below table. Table 6.0 : Recommended Locations for Corrosion Monitoring of Thien Ung Facilities. Fluid Produced Fluid

Monitoring Devices SC

Produced Fluid

SC

Dehydrated Gas

SC

Gas/ Condensate Mixture Dehydrated Condensate Potable Water

CC, ER, SC

LP flare KO drum

SC

SC SC

Monitoring Location Liquid outlet of test separator Liquid outlet of production separator

Downstream lean TEG/ dehydrated gas heat exchanger Pipeline launcher and receiver Outlet of condensate dehydrator Downstream potable water UV sterilizer Liquid outlet of HP flare KO drum

Comments Monitor liquid quality Monitor combined produced liquid arrived from FDP and from HP flare KO drum pumps Monitor gas quality, pH etc. Monitor mixture quality, pH etc. Monitor condensate quality, pH etc. Monitor water quality before distribution to users. Bacteria count


REV. NO.



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7.0

REFERENCES

1)

Process And Utility Design Basis, 5691-GEN-PR-RPT-9901, Rev 0.

2)

Heat and Material Balance, 5691-GEN-PR-HMB-XXXX, Rev 0.

3)

Process Flow Diagram, 5691-CPP-PR-PFD-XXXX, Rev 0.

4)

Utility Flow Diagram, 5691-CPP-PR-PFD-XXXX, Rev 0.

5)

NACE MR0175/ISO 15156-3 Petroleum and Natural gas Industries – Materials for Use in H2S Containing Environments in Oil and Gas Production - Cracking-resistant CRAs (corrosionresistant alloys) and other Alloys, 2009

6)

GM EP COR 037 Use of Corplus v2: Technical Support, 2007

7)

VSP Technical Sheet Comment for Material Selection and Corrosion Philosophy Report Rev. A, Sheet No: TW-GEN-PI-RPT-0005.

8)

5691-PM-MOM-0016, Progress Meeting 05-08-2011, Rev A.


REV. NO.



0 Page 24 of 33

APPENDIX 1 – CO2 CORROSION ASSESSMENT RESULT TABLE

Pipe Size Stream Stream Description DN(mm)

P (bar)

T ( C) °

CO2 H2S pCO2 (mol%) (mol%) (bar)

pH2S pH2S NACE (bar) (bar) (Y/N) operating design pressure pressure

pH

Case 2C: 4th Production Year Gas flow Oil flow Water flow Flow CO2 (MMSCMD) (m3/h) (m3/h) velocity Corrosiveness (m/s)

Cru A CA (mm/yr) (%) (mm)

Notes

Upstream of Choke Valve Downs tream of Choke Valve Gas from Tes t Separator

150

139.0

93.00

9.68

0.0021 13.46

0.0029

0.0145

Y

4.98

1.07

14.191

2.241

14.91

Very High

3

95

6.13

150

128.0

90.92

9.68

0.0021 12.39

0.0027

0.0145

Y

4.71

1.07

14.569

2.247

7.38

Very High

3

95

6.13

150

128.0

90.92

9.68

0.0021 12.39

0.0027

0.0028

N

4.71

1.07

-

0

6.46

Very High

7.09

95

11.24 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar

1D

Co nd en sa te F r om Test Separator

150

128.0

90.92

9.68

0.0021 12.39

0.0027

0.0028

N

4.71

0

14.569

0

1.57

Very High

3

95


1E

W at er Fr om Tes t Separator

150

128.0

90.92

9.68

0.0021 12.39

0.0027

0.0028

N

4.71

0

-

2.247

0.23

Very High

6.85

95


1F

FW S From Tes t Separator

150

127.0

90.73

9.68

0.0021 12.29

0.0027

0.0028

N

4.72

1.07

14.601

2.247

7.43

Very High

3

95


2

P ro du ct io n Co ol er Inlet

250

127.0

90.73

9.68

0.0021 12.29

0.0027

0.0028

N

4.72

3.66

49.935

7.685

5.69

Very High

7.06

95

11.20 N ACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar

102

Production Cooler Outlet

250

126.0

50.00

9.74

0.0020 12.27

0.0025

0.0027

N

4.67

3.49

68.802

8.293

2.62

Very High

3.68

95


103

Production Separator Inlet

400

126.0

50.00

9.74

0.0020 12.27

0.0025

0.0027

N

4.67

8.18

160.996

19.405

6.12

Very High

3.78

95

7.10 N ACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar

104

Gas from Production Separator

500

126.0

50.00

9.74

0.0020 12.27

0.0025

0.0027

N

4.67

8.18

0

0

3.76

Very Low

Note

95

105

Condensate From Prod. Separator

300

126.0

50.00

9.74

0.0020 12.27

0.0025

0.0027

N

106

Water From Prod. Separator

80

126.0

50.00

9.74

0.0020 12.27

0.0025

0.0027

N

107

Train 1 Dehydrated Gas Header

600

124.5

52.87

9.76

0.0021 12.15

0.0026

0.0028

N

108

Lean TEG/Dehyd. Gas HX Gas Outlet

600

124.5

52.87

9.76

0.0021 12.15

0.0026

0.0028

N

109

TEG Contactor Inlet Scrb. Inlet Header

500

126.0

50.34

9.75

0.0020 12.29

0.0025

0.0027

N

110

TEG Contactor Inlet

500

126.0

50.34

9.75

0.0020 12.29

0.0025

0.0027

N

111

L iq . F rom TE G Contactor Inlet Scrubber De hy dr at ed Ga s From TEG Contactor Train 1 Dehydrated Gas Header

50

126.0

50.34

9.75

0.0020 12.29

0.0025

0.0027

N

600

125.5

51.34

9.76

0.0021 12.25

0.0026

0.0028

N

600

124.5

52.87

9.76

0.0021 12.15

0.0026

0.0028

N

1A 1B 1C

1 14 115

F ue l G as Ta p O ff Gas Cust ody Metering Inlet Hdr.

1 50 600

1 24 .5 124.5

5 2. 87 52.87

9 .7 6 9.76

0 .0 02 1 1 2. 15 0.0021 12.15

0 .0 02 6 0.0026

0 .0 03 8 0.0038

Y Y

Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. 4.67 0 160.957 0.323 0.95 Very High 3 95 6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 4.67 0 0.038 19.082 0.68 Very High 3.69 95 6.99 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 4.66 10.22 0 0 3.26 Very Low Note 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. 4.66 10.22 0 0 3.26 Very Low Note 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. No flowrates given in the H&MB, materials will be the same as other material in the NACE is recommended for materials uniformity system. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Id en ti fi ed as de hy dr at ed li ne s, t he re fo re th e c or ro si on is ve ry m in im al an d C S 3 mm CA is s uf fi ci en t. Identified as dehydrated li nes, therefore the corrosion is very minimal and LTCS 3mm CA is sufficie nt.

116

Gas Cust ody Metering Outlet

600

123.5

52.54

9.76

0.0021 12.05

0.0026

0.0038

Y

Identified as dehydrated li nes, therefore the corrosion is very minimal and LTCS 3mm CA is sufficie nt.

117

Dehydrated Gas to Static Mixer Export to Subsea P/L Prod. Sep. Cond. Pumps Discharge

600

121.0

51.69

9.76

0.0021 11.81

0.0025

0.0038

Y


600

120.5

51.33

9.78

0.0020 11.78

0.0024

0.0036

Y


150

131.0

50.29

9.74

0.0020 12.76

0.0026

0.0028

N

4.65

0

160.747

0.322

2.65

Very High

3

95


Train 1 Cond. Filter Outlet

150

129.0

50.35

9.74

0.0020 12.56

0.0026

0.0028

N

4.65

0

160.894

0.322

2.65

Very High

3

95


1 12

113

118 119

120

-


REV. NO.


Stream Stream Description

Pipe Size DN(mm)

P (bar)

T ( C) °


pH2S pH2S NACE (bar) (bar) (Y/N) operating design pressure pressure

pH


0 Page 25 of 33

Case 2C: 4th Production Year Gas flow Oil flow Water flow Flow CO2 (MMSCMD) (m3/h) (m3/h) velocity Corrosiveness (m/s)


Notes

121

Train 1 Cond. Coalescer Outlet

150

128.0

50.35

9.74

0.0020 12.47

0.0026

0.0028

N

4.66

0

160.959

0.034

2.65

Very High

3

95


122

Water From Train 1 Cond. Coalescer

50

128.0

50.35

9.74

0.0020 12.47

0.0026

0.0028

N

4.66

0

0

0.287

0.04

Very High

3.66

95


124

Train 1 Dewatered Cond. D/S LV

150

123.0

50.27

9.82

0.0021 12.08

0.0026

0.0029

N

4.67

0.01

24075

0.034

2.62

Very High

3

95


125

Cond. From Condensate Dehydrator Con d. Cu st ody Metering Outlet Hdr Dehydrated Cond. To Static Mixer Stripping Gas Tap Off

350

123.5

50.28

9.76

0.0021 12.05

0.0026

0.0038

Y

Identified as dehydrated li nes, therefore the corrosion is very min imal and LTCS 3mm CA is sufficie nt.

200

126.5

50.55

9.76

0.0021 12.35

0.0027

0.0038

Y


200

121.0

50.52

9.85

0.0021 11.92

0.0025

0.0038

Y


200

125.5

51.34

9.76

0.0021 12.25

0.0026

0.0028

N

Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm CA is sufficient.

129

Cond. Dehydrator Stripping Gas Inlet

200

123.5

50.67

9.76

0.0021 12.05

0.0026

0.0028

N

130

Rewetted Strip ping Gas Outlet

250

123.0

49.90

9.77

0.0021 12.02

0.0026

0.0028

N

131

Rewetted Strip ping Gas Suct. Scrb. Gas Outlet

250

123.0

49.90

9.77

0.0021 12.02

0.0026

0.0028

N

132

Rewetted Strip ping Gas Suct. Scrb. Liq. Outlet Rewetted Strip ping Gas Comp. Disch.

50

123.0

49.90

9.77

0.0021 12.02

0.0026

0.0028

N

250

126.0

51.73

9.77

0.0021 12.31

0.0026

0.0028

N

126 127 128

134

Cond . B oos ter Pumps Discharge

300

127.5

50.52

9.76

0.0021 12.44

0.0027

0.0028

N

135

Con d. Cu st ody Metering Inlet Hdr

300

127.5

50.52

9.76

0.0021 12.44

0.0027

0.0028

N

1 40

D eh yd ra te d G as D/stream Stripping Gas Tap Off Main Dehydrated Gas Header 2 -P has e Ex por t Header

500

125.5

51.34

9.76

0.0021 12.25

0.0026

0.0028

N

600

124.5

52.87

9.76

0.0021 12.15

0.0026

0.0038

Y

NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 4.67 2.05 0 0 6.01 Very Low Note 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to t emperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. 4.67 2.05 0 0 6.01 Very Low Note 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to t emperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. No flowrates given in the H&MB, materials will be the same as other material in the NACE is recommended for materials uniformity system. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 4.66 2.05 0 0 5.87 Very Low Note 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to t emperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated li nes, therefore the corrosion is very min imal and LTCS 3mm CA is sufficie nt.

600

121.0

51.46

9.77

0.0020 11.82

0.0024

0.0036

Y


133

141 142

Where: Cri: Inhibited Corrosion Rate; Cru: Uninhibited Corrosion Rate; A: Inhibitor efficiency; CA: Corrosion Allowance. CA = (Cri*(A %) /100*Design Life) + (Cru*(1-((A %) /100))*Design Life) Ex: 0.1* 95%/100* 25yr + 7.09mm/yr* [1-(95%/100)]* 25yr = 11.237mm (Stream 1C Case 2C)


REV. NO.

Material Selection and Corrosion Philosophy Report Pipe Size DN(mm)

P (bar)

T ( C)

Upstream of Choke Valve Downs tream of Choke Valve Gas from Tes t Separator

150

55.0

77.00

9.68

pH2S pH2S NACE (bar) (bar) (Y/N) operating design pressure pressure 0.0021 5.32 0.0012 0.0145 Y

150

54.5

76.85

9.78

0.0021 5.33

0.0011

0.0145

Y

150

54.5

76.85

9.78

0.0021 5.33

0.0011

0.0028

N

1D

Co nd en sa te F r om Test Separator

150

54.5

76.85

9.78

0.0021 5.33

0.0011

0.0028

N

1E

W at er Fr om Tes t Separator

150

54.5

76.85

9.78

0.0021 5.33

0.0011

0.0028

1F

FW S From Tes t Separator

150

53.5

76.55

9.78

0.0021 5.23

0.0011

2

P ro du ct io n Co ol er Inlet

250

53.5

76.55

9.78

0.0021 5.23

102

Production Cooler Outlet

250

52.5

50.00

9.90

103

Production Separator Inlet

400

52.5

50.00

104

Gas from Production Separator Condensate From Prod. Separator

500

52.5

300

106

Water From Prod. Separator

107


1A

°


pH

0 Page 26 of 33

Case3C: 10th Production Year Gas flow Oil flow Water flow Flow CO2 (MMSCMD) (m3/h) (m3/h) velocity Corrosiveness (m/s)


14.972

2.314

15.05

Very High

4.98

1.08

14.962

2.314

16.21

4.98

1.08

-

0

15.21

4.98

0

14.962

0

N

4.98

0

-

0.0028

N

4.98

1.08

0.0011

0.0028

N

4.98

0.0021 5.20

0.0011

0.0028

N

9.90

0.0021 5.20

0.0011

0.0028

N

50.00

9.90

0.0021 5.20

0.0011

0.0038

Y

52.5

50.00

9.90

0.0021 5.20

0.0011

0.0028

N

80

52.5

50.00

9.90

0.0021 5.20

0.0011

0.0028

N

Train 1 Dehydrated Gas Header

500

161.0

50.00

9.93

0.0021 15.99

0.0034

0.0028

N

108

Lean TEG/Dehyd. Gas HX Gas Outlet

600

51.0

53.70

9.94

0.0021 5.07

0.0011

0.0028

N

110

TEG Contactor Inlet

500

52.5

50.63

9.91

0.0021 5.20

0.0011

0.0028

N

111

L iq . F rom TE G Contactor Inlet Scrubber De hy dr at ed G as From TEG Contactor Train 1 Dehydrated Gas Header

50

52.5

50.63

9.91

0.0021 5.20

0.0011

0.0028

N

6 00

5 2. 0

5 1. 63

9 .9 4

0 .0 02 1 5 .1 7

0 .0 01 1

0 .0 03 8

Y

600

50.0

53.23

9.94

0.0021 4.97

0.0011

0.0028

N

F ue l G as Ta p O ff Gas Cust ody Metering Inlet Hdr. Gas Cust ody Metering Outlet

1 50 600

1 61 .0 161.0

5 0. 00 50.00

9 .9 4 9.94

0 .0 02 1 1 6. 00 0.0021 16.00

0 .0 03 4 0.0034

0 .0 03 8 0.0038

Y Y

NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Id en ti fi ed as d eh yd ra te d l in es , th er ef or e t he c or ro si on is ve ry m in im al an d L TCS 3m m CA is s uf fi ci en t. Identified as dehydrated li nes, therefore the corrosion is very minimal and LTCS 3mm CA is sufficie nt.

600

160.0

49.76

9.94

0.0021 15.90

0.0034

0.0038

Y


Dehydrated Gas to Static Mixer Export to Subsea P/L Prod. Sep. Cond. Pumps Discharge

600

157.5

49.16

9.94

0.0021 15.66

0.0033

0.0038

Y


600

157.0

51.13

9.69

0.0020 15.21

0.0031

0.0036

Y


150

57.5

50.25

9.90

0.0021 5.69

0.0012

0.0029

N

4.99

0

144.492

0.290

2.4

High

3

95

Train 1 Cond. Filter Outlet

150

55.5

50.31

9.90

0.0021 5.49

0.0012

0.0029

N

5.01

0

144.572

0.290

2.4

High

3

95

1C

105

1 12

113

1 14 115 116 117 118 119

120

3

95

Very High

3

95

Very High

7.73

95

1.6

Very High

3

95

2.314

0.24

Very High

6.74

95

14.942

2.312

16.21

Very High

3

95

3.69

51.101

7.908

13.38

Very High

7.46

95

5.03

3.6

61.833

8.515

6.79

High

2.56

95

5.03

8.41

144.638

19.918

15.89

High

3

95

8.41

0

0

9.93

High

2.75

95

0

144.599

0.290

0.86

High

3

95

Notes

1.08

1B

4.98


4.55

5.03

6.13 6.13 12.04 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 10.80 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 11.70 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.58 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.81

6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.03 0 0.039 19.626 0.71 High 2.59 95 5.61 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.03 9.84 0 0 8.14 Very Low Note 1 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar No flowrates given in the H&MB, materials will be the same as other material in the NACE is recommended for materials uniformity system. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Id en ti fi ed as d eh yd ra te d l in es , t he re fo re t he c or ro si on i s ve ry m in im al a nd LTCS 3 mm C A i s su ff ic ie nt .


6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar


REV. NO.


150

54.5

50.31

9.90

122

Water From Train 1 Cond. Coalescer

50

54.5

50.31

9.90

0.0021 5.40

0.0011

0.0029

N

5.02

0

0

0.252

0.04

High

2.63

95

124

Train 1 Dewatered Cond. D/S LV Cond. From Condensate Dehydrator Co nd. Cus tody Metering Outlet Hdr

150

49.5

50.21

10.17

0.0022 5.03

0.0011

0.0030

Y

5.05

0.01

143.629

0.037

0.14

High

1.78

95

3 50

5 0. 0

4 9. 78

9 .9 3

0 .0 02 1 4 .9 7

0 .0 01 1

0 .0 03 8

Y

I de nt if ie d as d eh yd ra te d l in es , t he re fo re t he c or ro si on i s ve ry m in im al a nd L TCS 3 mm C A is s uff ic ie nt .

200

160.0

55.18

9.93

0.0021 15.89

0.0034

0.0038

Y


Dehydrated Cond. To Static Mixer Stripping Gas Tap Off

200

157.5

55.27

9.93

0.0021 15.64

0.0033

0.0038

Y


200

52.0

51.63

9.94

0.0021 5.17

0.0011

0.0028

N


129

Cond. Dehydrator Stripping Gas Inlet

200

50.0

50.68

9.94

0.0021 4.97

0.0011

0.0028

N

130

Rewetted Strip pin g Gas Outlet

250

49.5

49.64

9.95

0.0021 4.93

0.0010

0.0028

N

131

Rewetted Strip pin g Gas Suct. Scrb. Gas Outlet

250

49.5

49.64

9.95

0.0021 4.93

0.0010

0.0028

N

132

Rewetted Strip pin g Gas Suct. Scrb. Liquid Outlet Rewetted Strip pin g Gas Comp. Disch.

50

49.5

49.64

9.95

0.0021 4.93

0.0010

0.0028

N

250

52.5

54.37

9.95

0.0021 5.22

0.0011

0.0028

N

127 128

°


pH

Case3C: 10th Production Year Gas flow Oil flow Water flow Flow CO2 (MMSCMD) (m3/h) (m3/h) velocity Corrosiveness (m/s)

Train 1 Cond. Coalescer Outlet

126

T ( C)

Page 27 of 33

121

125

P (bar)

0

pH2S pH2S NACE (bar) (bar) (Y/N) operating design pressure pressure 0.0021 5.40 0.0011 0.0029 N


Pipe Size DN(mm)



5.02

0

144.606

0.037

2.4

High

3

95

Notes

6.13 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.66 NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 4.60

Cond . B oos ter Pumps Discharge Co nd. Cus tody Metering Inlet Hdr Gas Com p. 24KQ110A/B-K10 Suction Gas Com p. 24KV105A/B Liq. Outlet Gas Comp. After Cooler 24E115A/B Inlet Gas Comp. After Cooler 24E115A/B Outlet

3 00

5 4. 0

4 9. 98

9 .9 3

0 .0 02 2 5 .3 6

0 .0 01 2

0 .0 03 0

Y

NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm NACE is recommended for materials uniformity CA is sufficient. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar 5.05 1.43 0 0 11.17 Very Low Note 1 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0. 003bar. 5.05 1.43 0 0 11.17 Very Low Note 1 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0. 003bar. No flowrates given in the H&MB, materials will be the same as other material in the NACE is recommended for materials uniformity system. in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar. 5.03 1.43 0 0 10.51 Very Low Note 1 95 Corplus gives "Very Low" results because of no water content inserted but in reality there will be water condensation due to temperature differences. NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0. 003bar. I de nt if ie d as d eh yd ra te d l in es , t he re fo re t he c or ro si on i s ve ry m in im al a nd L TCS 3 mm C A is s uff ic ie nt .

300

161.0

55.15

9.93

0.0022 15.99

0.0035

0.0030

Y


5 00

5 0. 0

5 3. 23

9 .9 4

0 .0 02 1 4 .9 7

0 .0 01 1

0 .0 03 8

Y

I de nt if ie d as d eh yd ra te d l in es , t he re fo re t he c or ro si on i s ve ry m in im al a nd L TCS 3 mm C A is s uff ic ie nt .

50

5 0. 0

5 3. 23

9 .9 4

0 .0 02 1 4 .9 7

0 .0 01 1

0 .0 03 8

Y

No fl owr at es gi ve n i n t he H& MB , m at er ia ls wi ll be t he sa me a s o th er ma te ri al in th e s ys t em .

400

162.0 165.79

9.94

0.0021 16.10

0.0034

0.0038

Y

Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm CA is suff icient.

350

161.0

50.00

9.94

0.0021 16.00

0.0034

0.0038

Y

143A/B Gas Comp. Suct. Scrb. 24V105A/B Inlet 1 40 De hy dr at ed Ga s D/stream Stripping Gas Tap Off 141 Main Dehydrated Gas Header 1 42 2 -P ha se E xp or t Header

5 00

5 0. 0

5 3. 23

9 .9 4

0 .0 02 1 4 .9 7

0 .0 01 1

0 .0 03 8

Y

There will be a large temperature difference between the upstream and downstream of the aftercooler and it is a concern if condensation will occur. However, according to process group simulation, no condensation will occur since the air is dehydrated. In case if condensation will occur, stainless steel tube will be recommended as an alternative. I de nt if ie d as d eh yd ra te d l in es , t he re fo re t he c or ro si on i s ve ry m in im al a nd L TCS 3 mm C A is s uff ic ie nt .

500

52.0

51.63

9.94

0.0021 5.17

0.0011

0.0028

N

600

161.0

50.00

9.93

0.0021 15.99

0.0034

0.0038

Y

NACE is recommended for materials uniformity in the system and to allow souring through 25 yrs design life although the pH2S is <0.003bar Identified as dehydrated lines, therefore the corrosion is very minimal and LTCS 3mm CA is sufficient.

600

157.5

51.22

9.69

0.0020 15.26

0.0032

0.0036

Y


133

134 135 136A/ B

137A/ B

138A/B

139A/B



REV. NO.



0 Page 28 of 33

APPENDIX 2 – MATERIAL SELECTION TABLE

Stream/ Equipment Description No. Process Piping 1A Upstream of Choke Valve 1B Downstream of Choke Valve 1C Gas from Test Separator 1D Condensate From Test Separator 1E Water From Test Separator 1F FWS From Test Separator 2 Production Cooler Inlet 102 Production Cooler Outlet 103 Production Separator Inlet 104 Gas from Production Separator 105 Condensate From Prod. Separator 106 Water From Prod. Separator 107 Train 1 Dehydrated Gas Header 108 Lean TE G/ Dehy drat ed Gas HX Gas / Outlet 109 TEG Contactor Inlet Scrb. Inlet Header 110 TEG Contactor Inlet 111 Liq. From TEG Contactor Inlet Scrubber 112 Dehy drat ed Gas from TE G Cont ac tor 113 Train 1 Dehydrated Gas Header 114 Fuel Gas Tap Off 115 116 117 118 119 120 121 122

Gas Custody Metering Inlet Hdr. Gas Custody Metering Outlet Hdr. Dehydrated Gas to Static Mixer Export to Subsea P/L Prod. Sep. Cond. Pumps Discharge Train 1 Cond. Filter Outlet Train 1 Cond. Coalescer Outlet Water From Train 1 Cond.Coalescer

124 125 126 127 128 129 130 131

Train 1 Dewatered Cond. D/S LV Cond. From Condens at e Dehy drat or Cond. Cus tody Metering Out let Hdr. Dehydrated Cond. To Static Mixer Stripping Gas Tap Off Cond. Dehy drat or S tri ppi ng Gas Inl et Rewetted Stripping Gas Outlet Rewetted Stripping Gas Suct. Scrb. Gas Outlet Rewetted Stripping Gas Suct. Scrb. Liq. Outlet Rewetted Stripping Gas Comp. Disch. Cond. Booster Pumps Discharge Cond. Custody Metering Inlet Hdr. Gas Comp. 24KQ110A/B-K10 Suction Gas Comp. 24K V105A /B Liq. Out let Gas Comp. After Cooler 24E115A/B Inlet Gas Comp. After Cooler 24E115A/B Outlet Gas Comp. Suct. Scrb. 24V105A/B Inlet Dehydrated Gas D/stream Stripping Gas Tap Off

132 133 134 135 136A/B 137A/ B 138A/B 139A/B 143A/B 140

141 142

Main Dehydrated Gas Header 2-Phase Export Header

Recommended Material/ Internal Protection

Alternative Material

DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE DSS NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE

Comments

NACE is recommended for materials uniformity in the syst em and to allow souring through 25 yrs design life although the pH2S is <0.003bar.

DSS NACE DSS NACE DSS NACE LTCS + 3mm CA NA CE LTCS + 3mm CA NACE CS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE DSS NACE DSS NACE DSS NACE DSS NACE


DSS NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NA CE DSS NACE DSS NACE


DSS NACE DSS NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NA CE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE LTCS + 3mm CA NACE

LTCS + 3mm CA NACE LTCS + 3mm CA NACE

SS316L NACE NACE is recommended for materials uniformity in the syst em and to allow souring through 25 yrs design life


REV. NO.

Material Selection and Corrosion Philosophy Report Process Equipme nt 20V105


0 Page 29 of 33

Test Separator

CS with Alloy 625 cladded

CS with SS316L cladded*

*Usage of CS with SS316L cladded requires qualification testing by the Client

20E115

Production Cooler

20V110

Production Separator

DSS Tubes, CS with Alloy 625 c ladded Header CS with Alloy 625 cladded

CS with SS316L cladded*

*Usage of CS with SS316L cladded requires qualification testing by the Client

22V105 TEG Contactor Inlet Scrubber 22V110 TEG Contactor 29M120 Gas / Condensate Static Mixer 30P105A/B/C Train 1 Condensate Booster Pumps 30S110A/B Train 1 Condensate Filters 30S 115A/ B Train 1 Condens ate Coales cers 30V105 Condensate Dehydrator 30V110 Rewetted Stripping Gas Suction Scrubber Potable Water and Wash Water System Piping From To Stream 1 Stream 2 Stream 3 Stream 4 Stream 5 Stream 6 Stream 7 Stream 8 Stream 9 Potable Wa ter and Wa sh Water System Equipment 52T110 Potable Water Storage Tank

52P115A/ B 52V125

CS with SS316L cladded CS with SS316L cladded CS HOLD CS with SS316L cladded CS wit h S S316L c ladded CS with SS316L cladded CS with SS316L cladded

CuNi SS316L SS316L SS316L SS316L SS316L CS + 3mm CA CS + 3mm CA CS + 3mm CA

GRP

CS 3mm CA with epoxy internal coating* or GRP

CS with SS316L cladded/ solid SS316L

*Coating to be approved by HSE. For the alternative material, cladded or solid SS316L to be selected depending on the vessel dimension.

CS with SS316L cladded/ solid SS316L

*Coating to be approved by HSE. For the alternative material, cladded or solid SS316L to be selected depending on the vessel dimension.

Potable Water Pumps Pressurized Potable W ater Vessel

SS316 CS 3mm CA with epoxy internal coating* or GRP

52S120

Potable Water Filter

51T105

Wash Water Tank

SS316L vessel and internals CS 3mm CA with epoxy internal coating

51P110

Wash Water Pump

CS

Seawater System Piping From To Whole System Seaw ater System Equipment 53P105A/ B Seawater Lift Pumps 53T110A/ B Seawater Lift Caissons

53S115A/ B

Seawater Strainer

CuNi

GRP

SDSS CS 3mm CA internal and external + glass flake epoxy coating internal and external + sacrificial anode at the bottom SDSS

Ni-Al-Bronze


REV. NO.

Material Selection and Corrosion Philosophy Report Stream/ Equipment Description No. Instrument and Utility Air System Piping From To Stream 1 Stream 2 Stream 3 Stream 4 Stream 5 Stream 6 Stream 7 Instrument and Utility Air System Equipment 54V110 Wet Air Service

54V120

Instrument Air Receiver

Waste Heat Recovery and Hot Oil System Piping From To Whole System Waste Heat Recovery a nd Hot Oil System Equipment 56V115 Hot Oil Expansion Vessels 56P110A/ B Hot Oil Circulation Pumps 56S120 Hot Oil Side Stream Filter 56E125 Hot Oil Trim Cooler Sewage System Piping From To Stream 1 Stream 2 Stream 3 Sewage System Equipment 57T110 Sewage Water Disposal Caisson

Nitrogen System Piping From To Stream 1 Stream 2 Stream 3 Stream 4 Stream 5 Stream 6 Stream 7 Stream 8 Stream 9 Stream 11 Nitrogen System Equipment 59V110 Nitrogen Receiver


SS316L SS316L SS316L SS316L SS316L SS316L SS316L CS 3mm CA with epoxy internal coating CS 3mm CA with epoxy internal coating

CS + 3mm CA CS + 3mm CA CS CS CS + 3mm CA

GRP GRP GRP CS 3mm CA internal and external + glass flake epoxy coating internal and external + sacrificial anode at the bottom

SS316L CS + 3mm CA SS316L CS + 3mm CA CS + 3mm CA CS + 3mm CA CS + 3mm CA CS + 3mm CA CS + 3mm CA CS + 3mm CA CS 3mm CA with internal coating

0 Page 30 of 33


Galvanized Galvanized Galvanized Galvanized Galvanized Galvanized Galvanized


CS CS CS CS CS CS CS

CS with SS316L cladded or solid SS316L CS with SS316L cladded or solid SS316L

Comments

VSP clarified that SS316L stainless steel is necessary for air before its cleaning but it is preferable to apply galvanized steel pipes after air cleaning [7], [8].

Cladded or solid SS316L to be selected depending on the vessel dimension. Cladded or solid SS316L to be selected depending on the vessel dimension.


REV. NO.

Material Selection and Corrosion Philosophy Report Stream/ Equipment Description No. Fuel Gas System Piping From To Whole System



0 Page 31 of 33


LTCS + 3mm CA NACE

Comments

Lower design temperature below 0 C, impact testing shall be performed. VSP requires SS316L to be applied from the filter to the turbine. °

HP Flare System Piping From To HP Flare Header Liquid Shutdown Valve (SDV) Discharge Outlet Shutdown HP Flare KO Drum Pumps Valve (SDV) HP Flare KO Production Separator Drum Pumps HP Flare KO HP Flare Tip Drum Process Drains Header

SS316L LT SS316L LT

6Mo 6Mo

CS 6mm CA with coating and inspection

DS S

Due to the drum design conditions. DS S i s rec om mended if mat erial uniformity with the production line is a concern.

DSS SS316L LT

6Mo


SS316L

Solid SS316L with external TSA coating SS316 SS316 SS310 for temperature exposed to oxidation/ scaling; SS316L minimum for lower temperature zones.

6Mo


SS316L

Alternative of SS316L for robust application to acc ommodate 25yrs design life

LP Flare KO HP Flare KO Header Drum


SS316L


LP Flare KO LP Flare Tip Drum


SS316L


CS 6mm CA with Phenolic coating*.

CS with SS 316L cladded

*Phenolic coating selection shall be qualified during detail engineering due to the high design temperature.

HP Flare System Piping Equipment 62V105 HP Flare KO Drum 62P115A/ B 62P115A/B 62A115

HP Flare KO Drum Pumps HP Flare KO Drum Booster Pumps HP Flare Tip

LP Flare System Piping From To LP Flare Header

LP Flare System Equipment 62V125 LP Flare KO Drum

62P135A/B 62A130

LP Flare KO Drum Pumps LP Flare Tip

CS SS310 for temperature exposed to oxidation/ scaling; SS316L minimum for lower temperature zones.

Material selection to be confirmed with the vendor.

Material selection to be confirmed with the vendor.


REV. NO.

Material Selection and Corrosion Philosophy Report Stream/ Equipment No. CPP Closed From CPP Closed Drain Vessel CPP Closed Drain Vessel

Description and Open Drain Systems Piping To LP Flare Header CPP Closed Drain Vessel Pumps

CPP Closed HP Flare KO Drum Drain Vessel Pumps CPP Open Transfer Pots On CPP Celler Deck Drain Laydown Area Caisson

CPP Closed and Open Drain Systems Equipment 64V115 CPP Closed Drain Vessel

64P120A/B 65P130 65T125

CPP Closed Drain Vessel Pump CPP Open Drain Caisson Pump CPP Open Drain Caisson

Aviation Fuel System From To Whole System Diesel Fuel System Piping From To Whole System Diesel Fuel System Equipment 67S105 Raw Diesel Coarse Filter 67T110

Diesel Storage Tank

67P115A/ B 67S120A/ B

Diesel Transfer Pumps Diesel Filter Coalescers

Methanol Inje ction System Pi ping From To Whole System Methanol Injection System Equipment 68T115 Methanol Storage Tank



0 Page 32 of 33


Comments

CS + 3mm CA CS 6mm CA with coating and inspection

SS316L


SS316L


25Cr SDSS

CS with internal coating

CS with SS316L cladded

CS with 13Cr impeller SDSS CS 3mm CA internal and external + glass flake epoxy coating internal and external + sacrificial anode at the bottom

Alternative of SS316L for robust application to accommodate 25yrs design life Alternative of SS316L for robust application to accommodate 25yrs design life 25Cr SDSS is only applicable if the design temperature is to be reduced during detail desing engineering. Otherwise, alternative material will be limited to Titanium and Nickel Alloy. Coating to be qualified depending to the service conditions.

SS316 Ni-Al-Br

SS316L

CS + 3mm CA CS 3mm CA and SS316L internals. CS 3mm CA and SS316L internals. CS CS 3mm CA and SS316L internals.

CS + 3mm CA CS + 3mm CA

Corrosion Inhibitor Injection System Piping From To Whole System

SS316L

Corrosion Inhibitor Injection System Equipment 68T105 Corrosion Inhibitor Storage Tank

SS316L

GRP

VSP has experienced using GRP successfully for many years.

Material Selection and Corrosion Philosophy Report

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