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DUBAI PETROLEUM ESTABLISHMENT

Engineering Consultancy Service Contract

Pipeline Cathodic Protection Design Report

Document Number: D6316-141-RP-PL-0005, Rev. 1 Page 2 of 19

TABLE OF CONTENTS

Revision History .......................................................................................................................................................................... 3

1 Introduction ............................................................. ................................................................. ................................. 4

1.1 Scope of W ork ............................................................................................................................................................ 4

1.2 Abbreviations ............................................................................................................................................................ 6

1.3 Definitions .................................................................................................................................................................. 6

1.4 Units ........................................................................................................................................................................... 6

2 Codes, Standards and Specifications ......................................................................................................... .............. 7

2.1 Supplementary Design Codes and Standards ......................................................................................................... 7

2.2 Project Specifications ......................................................... ................................................................. ...................... 7

2.3 Project Documents .................................................................................................................................................... 7

3 Summary & Conclusions .............................................................. ................................................................. ........... 8

4 Design Data .............................................................. ................................................................. ............................... 10

4.1 Pipeline Data ............................................................ ................................................................. ............................... 10

4.2 Anode Data .............................................................................................................................................................. 10

4.3 Environment Data .............................................................. ................................................................. .................... 10 5 Pipeline Cathodic Protection Design Methodology .......................................................................... .................... 11

5.1 Current Demands ............................................................... ................................................................. .................... 11

5.2 Anode Net Mass ....................................................... ................................................................. ............................... 12

5.3 Anode Current Output ........................................................................................................................................... 12

6 Results ...................................................................................................................................................................... 14

6.1 Base Scope ..................................................... ................................................................. .......................................... 14

6.1.1 24 Inch Production Line from I to ZB ............................................................... .................................................... 14

6.1.2 12 Inch Water Injection Line from HH to FA ...................................................................................................... 14

6.1.3 12 Inch Water Injection Line from LL to CC ............................ ................................................................. ......... 15

6.1.4 12 Inch Water Injection Line from KK to FF ...................................................................................................... 15

6.1.5 12 Inch Water Injection Line from II to GG ........................................................................................................ 16

6.2 Optional Scope ......................................................... ................................................................. ............................... 17

6.2.1 14 Inch Water Injection Line from U to ZA ................................................................................................ ......... 17

6.2.2 20 Inch Water Injection Line from WF-1 to M .................................................................................................... 17

6.2.3 14 Inch Water Injection Line from WF-1 to U ..................................................................................................... 18

6.2.4 18 Inch Water Injection Line from WF-1 to ZC ........................................................ .......................................... 18

Appendix A: CP Design Calculation Sheet (Typical) ............................................................................................................ 19

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Revision History

Revision Description

A1 Issued for IDC

A Issued for Approval

0 Approved for Design

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1 Introduction

Dubai Petroleum Establishment is planning to replace existing pipelines and also install new pipelines inthe Fateh and South West Fateh Fields as part of the 2014 Pipelay Campaign. The 2014 Pipelay Campaigncovers the following base scope and optional scope pipelines.

Base Scope Pipelines:

New 24 production line with an approximate length of 2.1 km from platform I to ZB in Fateh field New 12 water injection line with an approximate length of 2.3 km from platform LL to CC in SWF

field

New 12 water injection line with an approximate length of 2.5 km from platform KK to FF in SWF

field Replacement of existing 12 water injection line with an approximate length of 12.7 km from

platform HH to FA in SWF field Replacement of existing 12 water injection line with an approximate length of 0.9 km from

platform II to GG in SWF field

Existing risers at platforms HH and FA will not be replaced. Subsea tie-in to the existing risers will be performed by using smart flanges.

Replacement of Optional Scope Pipelines: Existing 14 water injection line with an approximate length of 0.7 km from platform U to ZA in

Fateh field Existing 20 water injection line with an approximate length of 3.5 km from platform WF -1 to M in

Fateh field Existing 14 water injection line with an approximate length of 2.9 km from platform WF -1 to U in

Fateh field Existing 18 water injection line wit h an approximate length of 3.3 km from platform WF-1 to ZC in

Fateh fieldExisting 14inch risers at platforms U, ZA and WF-1 will not be replaced. Also existing 20inch risers at

platforms WF-1 and M will not be replaced.

1.1 Scope of W ork

The objective of this document is to present the analysis carried out to calculate the cathodic protectiondesign requirement for the pipeline and risers under the Base and Optional scope against external corrosionduring their design life of 25 years.

The pipeline and risers will be coated and will have sacrificial aluminum anodes attached to providesufficient cathodic protection for the exposed surface area.

The CP calculation have been performed for the following pipelines under Base and Optional scope

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Base Scope

24inch Production Pipeline from I to ZB

12inch Water Injection Pipeline from HH to FA

12inch Water Injection Pipeline from LL to CC

12inch Water Injection Pipeline from KK to FF

12inch Water Injection Pipeline from II to GG

Optional Scope 14inch Water Injection Pipeline from U to ZA

12inch Water Injection Pipeline from WF-1 to M

12inch Water Injection Pipeline from WF-1 to U

12inch Water Injection Pipeline from WF-1 to ZC

CP requirements for risers and spools in Base and Optional scope are also presented in this report.

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1.2 Abbreviations

3LPP Three Layer Polypropylene

DNV Det Norske Veritas

DPE Dubai Petroleum Establishment

FEED Front End Engineering Design

SCFD Standard Cubic Feet per Day

NPS Nominal Pipe SizeOD Outside Diameter

SMLS Seamless

SMTS Specified Minimum Tensile Strength

SMYS Specified Minimum Yield Stress

TBC To Be Confirmed

1.3 Definitions

COMPANY : Dubai Petroleum Establishment (DPE)

PROJECT : 2014 Pipelay Campaign

CONTRACTOR : EPC Contractor

SUPPLIER : The party which manufactures and/or supplies goods or System and services to perform the duties specified by CONTRACTOR

1.4 Units

Data presented in this document are expressed in the System International (SI) units of measurements.

Other units for Standard flow rate (SCFD), pipe and piping component size (in), temperature (o

C), force(T), pressure (psig or barg) and combinations of the compass directional bases (N,E,S,W) may bedisplayed in addition to the SI units.

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2 Codes, Standards and Specifications

This section specifies the regulations, codes and standards applicable to the FEED of the pipelines andsubsea facilities. The subsea pipelines system will be designed to meet the Companys requirements and tosatisfy applicable industry standards. Latest edition of the standards and specifications shall be used unlessnoted otherwise.

The FEED of the pipeline systems shall be performed as per Det Norske Veritas (DNV standards inconjunction with DPE). DNV OS F101 Rules for Submarine Pipeline Systems will be used as a primarydesign codes in this study.

2.1 Supplementary Design Codes and Standards

The supplementary international codes that will be used where applicable and required are listed here below:

Table 2.1: Supplementary Design Codes and Standards

Ref No. Code/Std. No. Title

[1] API 5L Specification for Line Pipe, 44 th edition, 2008

[2] ANSI/ASME B36.10 Welded and Seamless Wrought Steel Pipe, 2004

[3] DNV OS F101 Rules for Submarine Pipeline Systems, 2012

[4] DNV-RP-F103 Cathodic Protection of Submarine Pipelines by Galvanic Anodes

2.2 Project Specifications

In addition to the applicable standards/codes referred in Section 2.1, the design of the pipeline system shallcomply with the COMPANY codes and standards specified in Table 2.2

Table 2.2: DPE Design Codes and Standards

Ref No. Code/Std. No. Title

[5] DP-PL-1 Submarine Pipeline Design

2.3 Project Documents

The relevant project documents are presented in Table 2.3.

Table 2.3: Project Documents

Ref No. Doc. No. Title

[6] D6316-141-DB-PL-0001 Pipeline and Riser Design Basis
http://webstore.ansi.org/RecordDetail.aspx?sku=ASME+B36.10M-2004http://webstore.ansi.org/RecordDetail.aspx?sku=ASME+B36.10M-2004

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3 Summary & Conclusions

The cathodic protection design for the subsea pipelines has been performed in accordance withDNV RP F103 [Ref. 4]. CP design has been carried out by assuming constant design temperature profilethroughout the length of the pipelines both in Base and Optional Scope

The detailed results of the CP design for Base and Optional Scope of pipelines are presented in section 6of this document and the summary of the results of CP design for Base and Optional Scope of pipelines are

presented in Table 3.1 and Table 3.2 respectively.

Table 3.1: CP Design Summary [Base Scope]

PipelinesOD

(mm)PipelineSegment

Proposed Anode Details

AnodeType

AnodeLength (2)

AnodeMaterial

AnodeThickness

AnodeSpacing(joints) (3)

Net mass per each

Anode(kg)

24 Production Linefrom I to ZB

609.6 PipelineHalf ShellBracelet

Type200 Al-Zn-In 40 6 38

12 Water InjectionLine from HH to FA



12 Water InjectionLine from LL to CC



12 Water InjectionLine from KK to FF



12 Water InjectionLine from II to GG

323.9 Pipeline Half ShellBraceletType

200 Al-Zn-In 40 6 21

Notes:

1. The length of riser and spool is approximate and subject to verification in detail engineering stage

2. A minimum length of 200mm has been selected to minimize fabrication and installation issues with anodemanufacturing

3. Anode spacing has been selected as per DP-PL-1

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Table 3.2: CP Design Summary [Optional Scope]

PipelinesOD

(mm)PipelineSegment

Proposed Anode Details

AnodeType

AnodeLength (2)

AnodeMaterial

AnodeThickness

AnodeSpacing(joints) (3)

Net mass per each

Anode(kg)

14 Water Injection

Line from U to ZA355.6 Pipeline

Half ShellBracelet


20 Water InjectionLine from WF-1 to M

508 PipelineHalf ShellBracelet


14 W ater InjectionLine from WF-1 to U



18 Water InjectionLine from WF-1 to ZC


Type

200 Al-Zn-In 40 6 29

Notes:

1. The length of riser and spool is approximate and subject to verification in detail engineering stage



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4 Design Data

4.1 Pipeline Data

The pipeline design and operation data, pipeline material properties, design temperature profile and design pressure profiles are presented in Section 3 of [6].

4.2 Anode Data

The anode is Half Shell Bracelet Type made of Aluminium, Zinc and Indium Alloy.

4.3 Environment DataThe environmental data including sea water properties, water depth, tide, sea water temperature, wave andcurrent data is presented in Section 4.1 to 4.7 of [6].

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5 Pipeline Cathodic Protection Design Methodology

The size and the dimension of anodes will be determined by the cathodic protection design.The cathodic protection design consists of calculating anodes spacing, as function of anode length, required to satisfymean current requirement based on mass consumption rate and final current requirements based on currentoutput of the consumed anode. The mean and final current demands are checked to ensure that the anodescan provide sufficient current output to polarize the pipeline throughout its entire life.

The pipeline cathodic protection will be carried out using MathCAD. The key of the analysis are asfollowing:

Current Demand Analysis for Mean and Final Life (Section 5.1)

Anode Net Mass Analysis (Section 5.2)

Anode Current Output Analysis based on Ohms law (Section 5.3)

5.1 Current Demands

In order to determine the mass of anode required for the cathodic protection system, it is necessary tocalculate the current demand to achieve polarization during the design life of the system as follows:

cccc f i A I

where:

Ic is the current demand for a specific surface area (mean I cm, final I cf ), A

Ac is the cathode surface area, m2

ic is the design current density (mean i cm, final i cf ), A/m2

f c is the coating breakdown factor (mean, final)

a, b is the constant values depend on coating properties and the environment

t is the coating life time, min

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5.2 Anode Net Mass

The total mass of anode required to maintain cathodic protection for the design life can be calculated asfollows:

u

t I M f cma

8760

where:

M a is the total net anode mass required, kg

Icm is the mean current demand, A/m2

tf is the design life, yr

u is the anode utilization factor, 0.8 for bracelet anode

is the electrochemical capacity, A-hr/kg

The total net anode mass provided must be more than or equal to that required for cathodic protection to besustained throughout the design life.

5.3 Anode Current Output

The individual anode current output, required to meet the current demand, is calculated from Ohms law.

af

oa

oc

af cf R E E

N I N I

fina l af

A R

315.0

where:

Icf is the final current demand, A

Iaf is the final anode current output, A

N is the number of anodes required

Eco is the design closed circuit potential of the anode, V

Eao is the design protective potential, V

R af is the final anode resistance, Ohm

is the environmental resistivity, Ohm-m

A final is the final anode exposed surface area, m2

The final anode resistance is determined from the initial anode dimensions by assuming that the anode is

consumed to its utilization factor, which would give a final exposed surface area and corresponding anoderesistance.

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The following will be applied in defining anode spacing :

Anode production constraints dictate that the half-shell bracelet length should not be longer than1000 mm. above this value, difficulties of excessive alloy cooling during casting occurs.

For very thin anodes (thickness lower than 50 mm), this length shall be reduced to about 600 mm.The anode thickness of all pipelines in base and optional scope is 40mm.

Anodes shorter than 200 mm present difficulties in core design.

The maximum anode spacing shall be 4 joints for 8 and less diameter pipelines as well as 6 jointsfor greater than 8 diameter pipelines as per DP-PL-1

Anode spacing should not be too short to avoid excessive anode fittings and particular anode fitted pipe handling precautions.

No anodes shall be placed on risers, anode designed to protect the riser shall be installed at thespool piece/ pipeline after the last riser bend.

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6 Results

This section present the results of cathodic protection design of pipelines under Base and Optional scope.The example of the cathodic protection design calculation is presented in Appendix A.

6.1 Base Scope

The results of cathodic protection design of pipelines under Base scope are mentioned below

6.1.1 24 Inch Production Line from I to ZBThe result of cathodic protection design of 24 inch production line from I to ZB is presented in Table6.1. 1

Table 6.1.1: Cathodic Protection Design Results for 24 Inch Production Line from I to ZB

OD(mm)

LocationSegment

length(m)

DesignTemp.

(oC)

Anode Details

Length

(mm) (2) Thickness

(mm)

Approx.Mass(kg)

Spacing as perDNV-RP-F103

(joints)

RecommendedSpacing (3)

609.6

Riser & Spool at I (1)

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4. Two anodes for each riser and two anodes for each spool is recommended

6.1.3 12 Inch Water Injection Line from LL to CC

The result of cathodic protection design of 12 inch water injection line from LL to CC is presented in Table6.1.3

Table 6.1.3: Cathodic Protection Design Results for 12 Inch Water Injection Line from LL to CC

OD(mm)

LocationSegment

length(m)

DesignTemp.

(oC)

Anode Details

Length

(mm) (2) Thickness

(mm)

Approx.Mass(kg)


(joints)


323.9

Riser & Spool at LL (1)

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4. Two anodes for each riser and two anodes for each spool is recommended. 6.1.5 12 Inch Water Injection Line from II to GG

The result of cathodic protection design of 12 inch water injection line from II to GG is presented in Table 6.1 .5

Table 6.1.5: Cathodic Protection Design Results for 12 Inch Water Injection Line from II toGG

OD(mm)

LocationSegment

length(m)

DesignTemp.(oC)

Anode Details

Length

(mm) (2) Thickness

(mm)

Approx.Mass(kg)


(joints)


323.9

Riser & Spool at II (1)

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6.2 Optional ScopeThe results of cathodic protection design for Optional scope of pipelines are mentioned below

6.2.1 14 Inch Water Injection Line from U to ZA

The result of cathodic protection design of 14 inch water injection line from U to ZA is presented in Table 6. 2.1

Table 6.2.1: Cathodic Protection Design Results for 14 Inch Water Injection Line from U to ZA

OD(mm) Location

Segment

length(m)

Design

Temp.(oC)

Anode Details

Length

(mm) (2) Thickness

(mm)Approx.Mass

(kg)

Spacing as perDNV-RP-F103(joints)


355.6

Riser & Spool at U (1)

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6.2.3 14 Inch Water Injection Line from WF-1 to UThe result of cathodic protection design of 14 inch water injection line from WF-1 to U is presented in Table6.2.3

Table 6.2.3: Cathodic Protection Design Results for 14 Inch Water Injection Line from WF-1 to U

OD(mm)

LocationSegment

length(m)

DesignTemp.

(oC)

Anode Details

Length

(mm) (2)

Thickness

(mm)

Approx.Mass(kg)


(joints)

Recommended

Spacing(3)

355.6

Riser & Spool at WF-1 (1)

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Appendix A: CP Design Calculation Sheet (Typical)

[1] API, Specification for American Petroleum, API Spec 5L

[2] ANSI/ASME, Welded and Seamless Wrought Steel Pipe, 2004, ANSI/ASME B36.10

[3] DNV-OS-F101, Rules for Submarine Pipeline Systems, 2012

[4] DNV, Cathodic Protection of Submarine Pipelines by Galvanic Anodes, DNV RP F103, 2010
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SUBSEA ENGINEERING

DUBAI PETROLEUM ESTABLISHMENT 2014 PIPELAY CAMPAIGN

24 inch Production Line from I to ZB Cathodic Protection - Bracelet, Half-shell Type Anode Design (KP0.0 to KP0.1)

Doc Title: CP DESIGN OFFSHORE PIPELINE

Pre. By:SC Date: 11/09/2013 Rev

Doc. No: D6316 141 RP PL005 Chk. By:NJ Date: 0

Table of Content

I. Introduction 2

2. Units 2

3. Codes, Standards and References 2

4. Design Data 2

5. Design of Cathodic Protection 4

6. Summary of Design 7

CP design (KP 0.0-KP 0.1).xmcd 1 of 8

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SUBSEA ENGINEERING

1. Introductio n

Cathodic Protection of 8" Gas Lift line from CI to PC20 by using Bracelet Half shell Type Anode Based onDNV-RP-F103,2010 and ISO 15589-2

User Manual

Guidlines: This Mathcad sheet is based on DNV-RP-F103, 2010 and ISO 15598-2. If any changes arerequired in the values taken form the above codes because of Client specific requirement , in that casethe Input values need to checked and revised as per the same.

2. Units

ORIGIN 1 c K joint 12.2 m

3. Codes, Stand ards and References:

Codes: DNV-RP-F103, 2010 (Cathodic Protection of Submarine Pipelines by Galvanic Anodes

Standards: ISO 15589-2 (Petroleum and Natural Gas Industries-Cathodic Protection ofPipeline Transportation system- Part 2 -Offshore Pipeline)

4. Desig n Data

4.1 Pipeline Material and Process Data

D 609.6 mm _ outside diameter of the pipe_including pipe OD tolerancestw 20.6 mm _ Pipeline wall thickness thickness

tc 2.5 mm _ corrossion coating thickness

mt 0.2 106

ohm m _Specific Electrical resistivity Based on LinepipeMaterial-extracted from Clause 5.6.10 of DNV-RP-F103

PLM "CM" _pipeine material type; CM for CMn steel linepipe CR for Type 13 Cr linepipe DX for duplex stainless steel pipe

Lp 100 m _total length of the pipeline (including corridor spool length)

Lcp 100 m _ equivalent length of the coated pipeline or spool

Lncp 0m _equivalent length of the bare pipeline or spool

T 115.6 c _ anode design temperature in degree centigrade

Tsea 19 c _sea water temperature

PCPE 100% _ percentage of pipeline exposed to sea water

PCAE 100% _ percentage of anode exposed to sea water

tfD 1 _ design factor for design life of pipeline (DNV-RP-F103Guidance note of Clause 1.2.1)(if not given then use t fD equal

to 1)


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SUBSEA ENGINEERING

tfg 25 _ design life of cathodic protection system given

tf

tfg

tfD

yr _ design life of cathodic protection system

Lcut 0mm _cutback length or FJ length

4.2 Sacrifi cial Anode Data (Brac elet, half-shell type)

a 2750 kg m3 _density of the anode material

u 0.8 _anode utilisation factor (From ISO15589-2, Sec 7.4)

25 mm _gap between the half shells

nac

2 _no of anode cores

wac 50 mm _width of the anode cores

tac 6 mm _thickness of the anode cores

nar 12 _no of reinforcement bars

dar 6 mm _diameter of the reinforcement bars

r 25 mm _end cover for the reinforcements

ac 10 mm _distance of anode core from pipe outer surface

s 7850 kg m3 _density of the steel

tr 3.mm _thickness of rubber sheet between anode and coated pipeline

ATY "AL" _anode type " AL " for Aluminium and " ZN " for Zinc anodes

4.3 Cathodic Protection requirment Parameters

S amax 24 joint _maximum spacing of anodes

4.4. Code Defined CP design Parameters

icm_e_cp 70 mA m2 _ average current density for fully

exposed coated pipeline (taken fromTable 5-1 of DNV-RP-F103)

E c .8 V _ protective potential wrt Ag / AgCl /Seawater as per Saudi Aramcorequirements

_ closed circuit anode potential for exposed pipeline wrt Ag / AgCl /Seawater Table 4 of ISO 15589-2:2004(E)

E a 1.05 V


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SUBSEA ENGINEERING

f cmp 3.25 103 _mean breakdown factor for pipeline

Table A1 of DNV RP F 103

_final breakdown factor for pipelineTable A1 of DNV RP F 103f cfp 4.5 10

3

_environmental seawater resistivity for fully exposed pipeline (As recommendedby Clause 5.5.2 of DNV RP F103 and asper Sec on A.8 of Annexure 8 of ISO15589 2)

0.3kg m

3

s3

A2

_ electrochemical effic iency for exposed

pipeline wrt Ag / AgCl / Seawater Asspecified by the saudi armaco standards17-SAMSS-006 material system spec

2.592 10

6 s A

kg

5. Design of Catho dic Prot ection

5.1 Surface Area and Weight of the Anode

x 0.001 0.002 1.50 _dimensionless variable for definingfunctions

Lamin nac 3 wac Lamin 0.25m _minimum anode width requiredLa x( ) Lamin x m _function defining length of the anode

Di D 2 t c 2 t r Di 0.621 m _inside diameter of the anode shell

Do Di 2 t a _outside diameter of the anode shellDo 0.701 m

Vac 4Di 2 ac tac 2 Di 2 ac 2 wac nac _Volume of the anode coreVac 1.219 L

Var x( ) n ar 4dar 2 La x( ) 2 r _Volume of the anode reinforcement

M1 x( ) 4Do

2Di

22 ta La x( ) Vac Var x( ) a _net mass of the anode without bolt

holes

M x( ) M1 x( ) 0.07 M 1 x( ) _net mass of anode(assuming 7%reduction for bolt holes)

Mg x( ) M x( ) Vac Var x( ) s _gross mass of the anodes


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SUBSEA ENGINEERING

Af x( ) Di 2 1 u( ) ta 2 La x( ) _final surface area of the anode at theend of life

5.2 Current Demand Calculations

_total number of jointsn j ceil

Lcp

joint

n j 9

L j 2 Lcut n j _total joint lengthL j 0

Icm_cp D Lcp f cmp icm_cp Icm_cp 0.044A _mean current demand for coated pipeline

Icm_ncp D Lncp icm_ncp Icm_ncp 0 _mean current demand for non-coatedpipeline

Icm Icm_cp Icm_ncp Icm 0.044 A _total mean current demand

Icf_cp D Lcp f cfp icm_cp Icf_cp 0.06A _final current demand for coated pipeline

Icf_ncp D Lncp icm_ncp Icf_ncp 0 _final current demand for non-coatedpipeline

Icf Icf_cp Icf_ncp Icf 0.06A _total final current demand

5.3 Total Anode Mass and Number of Anodes Calculation

Mt

Icm tf

u Mt 16.576 kg _total anode net mass

n x( )Mt

M x( ) _total number of the anodes

If x( )Icf

n x( ) _required final anode current output

Raf x( ) 0.315 Af x( )

_final anode resis tance

Iaf x( )E c E a

Raf x( ) _available final anode current


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SUBSEA ENGINEERING

1 10 4 0.36 0.72 1.08 1.44 1.80

5

10

15

Length of Anode (m)

C u r r e n

t ( A )

Iaf x( )

If x( )

La x( )

Number of Anodes Based on Selected Anode Length

x La sel Lamin m 1 _selected x value x 0.05

nar n x( ) _total no of anodes required nar 0.434

Sar

Lp

ceil n ar _required spacing of anodes

Sar

8.197 joint

S ap S sel _spacting of anodes to be provided S ap 97.6m

Check for Spacing

Check_sp if S ap S amax "Anode spacing exceeds 12 joints" "OK" Check_sp "OK"

nap ceilLp

S ap

_total number of anodes provided

nap 2

Ma nap M x( ) _total net mass of anode Ma 76.382 kg


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SUBSEA ENGINEERING

Check for mean current:

Icm 0.044 A _average current required

Iacmu Matf

_average current output Iacm 0.201 A

Check_mc "OK" I cm Iacmif

"Required current is greater than output current" otherwise

Check_mc "OK"

Check for fi nal curr ent:

Icf 0.06A _final current required

Iacf E c E a

Raf x( )nap _final current output Iacf 3.304 A

Check_fc "OK" I cf Iacf if

"Required current is greater than output current" otherwise

Check_fc "OK"

6. Summary of Design

ta 40 mm _thickness of anode

25mm _gap between half shells

S ap 8 joint _spacing of anodes (assuming 12.2 m joints)

nap 2 _no of anode

M x( ) 38.191 kg _net mass of each anode

Mg x( ) 48.158 kg _gross mass of each anode

Ma 0.076 tonne _total net mass of anode

Mgr Mg x( ) n ap Mgr 0.096 tonne _total gross mass of anodes

nac 2 _no of anode cores

wac 50mm _width of anode cores

tac 6 mm _thickness of anode cores

nar 0.434 _no of reinforcement bars

dar 6 mm _diameter of reinforcement bars

r 25 mm _end cover for reinforcements


8/12/2019 D6316-141-RP-PL-0005_1

27/27

SUBSEA ENGINEERING

Icm 0.044 A _average current required

Iacm 0.201A _average current output

Icf 0.06A _final current requiredIacf 3.304 A _final current output

Check_sp "OK" _check for spacing

Check_mc "OK" _check for mean current

Check_fc "OK" _check for final current

u 0.8 _anode utilisation factor

S ar 8.197 joint _required anode spacing

La sel 0.2m _selected length of each anode effectivetapered

Note: if selected anode length is not same as calculated length then the above parameter will be calculatedbased on the selected anode length and Lasel value will change as per selected anode length.

S sel 8 joint _selected anode spacing

ta 40 mm _thickness of the anode