Cathodic Protection Calculation

Document number

Contract : 4600002525

ID-SPU-GTSAA-1055-550025

CATHODIC PROTECTION CALCULATION System/Subsystem :

Document type : CAL

Discipline : PVV

Originator Document No :

Revision : 0.3

Status : AFC

Rev. Date : 28-Oct-2011 Page : 1 of 3

TOTAL E&P INDONESIE TN-AA85r/75rc WELL CONNECTION

CATHODIC PROTECTION CALCULATION

0.3

28-Oct-2011

AFC

APPROVED FOR CONSTRUCTION

SGK

SD

KOS/AA

0.2 0.1

13-Sep-2011

IFA

ISSUED FOR ACCEPTANCE

SGK

SD

KOS/AA

25-Aug-2011

IFC

ISSUED FOR COMMENT

SGK

SD

KOS/AA

Rev

Date

Status

Revision memo

Issued

Checked

Approved

This document is the property of TOTAL. and It shall not be disclosed to third parties or reproduced without permission of the COMPANY. Electronic Filename : ID-SPU-GTSAA-1055-550025_rev0.3.doc

COMPANY

Document number

Contract : 4600002525

ID-SPU-GTSAA-1055-550025

CATHODIC PROTECTION CALCULATION System/Subsystem :

Document type : CAL

Revision : 0.3

Discipline : PVV

Status : AFC

Rev. Date : 28-Oct-2011

Originator Document No :

Page : 2 of 3

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This document is the property of TOTAL. and It shall not be disclosed to third parties or reproduced without permission of the COMPANY. Electronic Filename : ID-SPU-GTSAA-1055-550025_rev0.3.doc

0.8

0.9

Contract : 4600002525

CATHODIC PROTECTION CALCULATION Document Type : CAL Originator Document No :

System/Subsystem :

Dicipline : PVV

Document Number ID-SPU-GTSAA-1055-550025 Revision : 0.3 Status : AFC Rev. Date : 28-Oct-2011

CATHODIC PROTECTION SIZING SACRIFICIAL ANODE SYSTEM TN-AA85/75 8"-G-J05P6-39AA01 AND 2"-IG-B05-39AA24 LINES Reference Document: GS-EP-COR-102 Rev. 6 Design of Cathodic Protection of Sealine by Sacrificial Anode GS-EP-COR-100 Rev. 7 Design of Cathodic Protection of Offshore Structure GS-EP-COR-201 Rev. 6 Supply of Sacrificial Anodes DNV Rp. B401 Cathodic Protection Design, 2005 Edition SNI 13-3474-2009 Description

Value

Unit

Anode Material Anode Weight (W Anode)

GALVALUM III 21

kg

Anode Temperature Consumption Rate (C R)

85 12.92

degC Kg/A.year

Utilization Factor (U) Length of anode (L anode) Initial anode outside diameter (OD anode)

0.85 40 26

cm cm (1" Thickness)

Gap between half cell (G) Minimum Design Life (T)

3 30

cm year

Coating type 1 Coating type 2

3L Polypropylene Painting P10 Mean Final 3% 5% 7% 13%

for 8" Flowline for 2" Instument Gas Line

Coating Damage Factor (B d1) Coating Damage Factor (B d2) Pipeline Temperature Current Density of Bare Pipe (I ds) Sea water resistivity (ρ) Potential of Aluminum vs Ag/AgCl Potential of polarized steel vs Ag/AgCl Difference in potential (dV) Description Outside diameter of pipe (OD1) Outside diameter of pipe (OD2) Length of pipe (L p) Surface area to be protected(A p1) Surface area to be protected(A p2) Estimated coating damage area (A d) Minimum current req. (Imin) (incl. 10% safety)

Minimum anode weight required (W min ) Minimum anode quantity (Q) Installed Anode Weight (Wi) Maximum spacing (S) Estimated Design Lifetime (Ti) Result (Design lifetime > Minimum lifetime) Output Current Check Surface area of anode (A anode) Resistance of bracelet anode (R anode) Potential output current per anode (Ia) Estimated coating damage area (A d) Minimum current req. (Imin) (incl. 10% safety)

Possible total current (I total)

Comment/Reference

Near steel temperature if bracelet type GS-EP-COR-102 Para. 6.2 GS-EP-COR-102 Para. 6.3

85 130

85 140

100 -1.05 -0.8 0.25

for 8" Flowline for 2" Instument Gas Line

GS-EP-COR-102 Table-2 GS-EP-COR-100 Para 5.5

degC mA/sqm

GS-EP-COR-102 Para. 5.2.3

ohm.cm (Buried in Mud) Volt Volt Volt Unit Inch Inch m sqm sqm sqm A Kg ea

Formula

π x OD1 x Lp π x OD2 x Lp Bd x Ap (at mean condition) Id x Ad x 1.1 (T x Cr x Imin) / U (W min / W anode)

Kg m year

Qi x Wanode Lp / Qi Wi x U / (Cr x Imin)

sqcm ohm A sqm A

(π x ODanode - 2xG) x Lanode x U 0.315*ρ / sqrt(Aanode) dV / Ranode Bd x Ap (at final condition) Id x Ad x 1.1

A

Q x Ia

Result (estimated output current > required output current)

GS-EP-COR-102 Para. 5.2.2 GS-EP-COR-102 Para. 6.2 GS-EP-COR-102 Para. 5.2.1

Values 8.625 2.375 2,457 1,691.02 465.64 83.33 11.916 5,433.6 259 5,983 9 33 Acceptable

2,573 0.621 0.403 145.08 22.34 114.70 Acceptable

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