Document Number/Номер документа O-4800-P-CAL-10001

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TENGIZCHEVROIL /ТЕНГИЗШЕВРОЙЛ PROJECT TITLE: DRILLING BASE NEW GAS SUPPLY SYSTEM НАЗВАНИЕ ПРОЕКТА: НОВАЯ СИСТЕМА ГАЗОСНАБЖЕНИЯ БАЗЫ БУРЕНИЯ PROJECT NUMBER/ НОМЕР ПРОЕКТА: O-4800-028-12 AFE NUMBER/ НОМЕР РОЗ: 9411110880 DOCUMENT TITLE: CP PARAMETERS CALCULATION НАЗВАНИЕ ДОКУМЕНТА: РАСЧЕТ ПО ОПРЕДЕЛЕНИЮ ПАРАМЕТРОВ КЗ DOCUMENT NUMBER / НОМЕР ДОКУМЕНТА: O-4800-P-CAL-10001   CONTRACTOR / ПОДРЯДЧИК: LLP “SPETSSTROYPROJECT” / ТОО спецСтройПроект SUPPLIER / ПОСТАВЩИК: PURCHASE ORDER (PO)/ЗАКАЗ НА ПОКУПКУ: SUPPLIER DOCUMENT NUMBER / НОМЕР ДОКУМЕНТА ПОСТАВЩИКА: SUPPLIER DOCUMENT REVISION / НОМЕР РЕДАКЦИИ ПОСТАВЩИКА:

THIS IS A CONTROLLED DOCUMENT. NO UN-AUTHORISED MODIFICATIONS ДАННЫЙ ДОКУМЕНТ ЯВЛЯЕТСЯ КОНТРОЛИРУЕМЫМ. НЕ ВНОСИТЬ НЕУТВЕРЖДЕННЫХ ИЗМЕНЕНИЙ THIS DOCUMENT IS DUAL LANGUAGE. ENSURE BOTH VERSIONS ARE MODIFIED. ДАННЫЙ ДОКУМЕНТ ВЫПОЛНЕН НА ДВУХ ЯЗЫКАХ. УБЕДИТЕСЬ, ЧТО ИЗМЕНЕНИЯ ВНЕСЕНЫ В ОБЕ ВЕРСИИ

В

18-02-2014

RE-IFC

NM

IZ

VB

A

12-12-2013

IFC

NM

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VB

REV/ РЕД.

DATE/ ДАТА

STATUS CODE / СТАТУС

BY / ПОДГ.

CHK/ ПРОВ.

APP/ УТВЕРДИЛ

PROJ/ ПРОЕКТ

CONST/ СТРОИТ. ОТДЕЛ

MAINT/ ТЕХ. ОБСЛ.

OPS/ ПРОИЗВ. ОТДЕЛ

REVISIONS РЕДАКЦИИ

PROJECT APPROVALS ДОКУМЕНТ УТВЕРЖДЕН ПРОЕКТОМ

TCO APPROVALS ДОКУМЕНТ УТВЕРЖДЕН ТШО

Revision description sheet / перечень редакций

REV. РЕВ.	PARA. ПАРАГ.	REVISION DESCRIPTION ОПИСАНИЕ РЕДАКЦИЙ
A		ISSUED FOR comment
A		ВЫПУЩЕНО ДЛЯ ЗАМЕЧАНИЙ
B		RE-ISSUED FOR comment
B		ВЫПУЩЕНО ПОВТОРНО ДЛЯ ЗАМЕЧАНИЙ

Signature Page: Страница подписей:

Approved: (Position)	Dzhanbatyrov Murat / Джанбатыров Мурат Bek-Ali Rafkat / Бек-Али Рафкат (FMPG Supervisor / Начальник ПГАХУ)	Утверждаю: (Должность)
Checked/Reviewed (Position))	Anton Knauer / Кнауэр Антон Cemil Kandemir / Джемиль Кандемир (Project engineer / Проектный инженер)	Проверено/Рассмотрено (Должность)
Approved: (Position)	Vladislav Bruzgulis/Владислав Брузгулис (Project engineer / Проектный инженер)	Утверждаю: (Должность)
Checked/Reviewed (Position)	Inessa Zhukovskaya/ Инесса Жуковская (Lid engineer / Вед.инженер)	Проверено/Рассмотрено (Должность)
Author: (Position)	Nataleya Maksimova/ Наталья Максимова (engineer / инженер)	Разработано: (Должность)

TABLE OF CONTENTS

1. EXECUTIVE SUMMARY

2. ABBREVIATIONS

3. CALCULATION OBJECTIVE    

4. CALCULATION METHOD

5. D ASSUMPTIONS

6. CP CALCULATION BASIS – DEFINES INPUT PARAMETERS

7. CALCULATION REPORT

8. CONCLUSIONS

9. CALCULATION METHOD FOR CP WITH GALVANIC ANODES

10. ATTACHMENT A

Soil Resistivity Measurements Report for the road

crossings in Tengiz DB

1. EXECUTIVE SUMMARY

1.1This document describes anode requirement calculations for galvanic anodes that will be used as supplement protection of casings on projected HP gaslines in TCO Drilling Base.

1.2 HP gasline with diameter of 114mm comprises of two joints, one of which is 6,3m from the tie-in point to the shut-off valve and 155m from the shut-off valve to the AGDS;HP gasline – crossings 1 to 3.

1.3 Above-ground sections of pipelines and valves are protected from outdoor corrosion by paint coating with thickness not less than 0.2 mm, applied over the degreased surface cleaned from rust and scale according to SNiP RoK of 2.01-19-2004. Underground sections of pipelines covered by heavy type insulation according to GOST of 9.602-2005 on the basis of adhesive PUF (polyurethane foam) coatings. Insulation design: is the primer “Primer” NC -50 according to TU 5775-001-01297859-95-1 layer; adhesive polythene tape «Polylene» according to TU 2245-003-01297859-99-2 layers; outer wrapper is polyethylene tape «Polylene-OB» according to TU 2245-004-01297859-99-1 layer. Isolation kit is provided on block valve station aboveground.

1.4 How and for how long the short section of 4” HP pipeline,located between the block valve tie-in point and the existing steel construction U/G 8” (200 mm) will be protected. These  recommendations shall be issued by the TCO Operations service

1.5 Although the gasline is located within TCO Industrial Base area it is used to supply gas to consumers rather than participate in gas production/processing process. Therefore CP parameters calculation has been made on the basis of the calculation methods described in RD 153-39.4-091-01

2. ABBREVIATIONS

Russian English Meaning

ББ DB Tengizchevroil Drilling Base

СНиП SNiP Construction Codes & Regulations

ВСН VSN Departmental Construction Codes

ГОСТ GOST Governmental Standard

РД RD Regulatory Document

ГРП GDDS Gas Drop Down Station

АГРС AGDS Automated Gas Distribution Station

КЗ CP Cathodic Protection

3. CALCULATION OBJECTIVE

Calculation objective is to present the basis of CP calculation for casings on projected HP gasline in TCO DB, as well as 6,3m and 155m gasline to show adequacy of the CP Design and spacing of Galvanic Anode Installation Test Posts.

4. CALCULATION METHOD

The below data has been used to calculate CP with galvanic anodes:

4.1 Casings and gasline dimensional details;

Galvanic anodes (protectors) dimensional and electrochemical parameters;

4.2 Soil resistivity measurements data provided earlier by Inzhtechservice company for the existing DB gaslines with the assumption that projected soil resistivity measurements will be within the presented one. For crossings 3 and 2 measurements are taken at the point 1.

For the pipeline and crossing 1 measurement data taken from one end at point 8.1, from the other end at point 1.2 and valued at average soil resistivity.

Calculation of CP with galvanic anodes will identify the following parameters:

• Current intensity in the protector – pipe circuit;

• Quantity of protectors required per each casing

• Protector’s design life

5. ASSUMPTIONS

The assumptions used for calculation of CP with galvanic anodes are as follows:

• Current density required

for soil with 10 Ohm resistivity maximum 10 mA/m²

• Coating breakdown 20 %

• Available magnesium in pre-packed anode 14.5(31,8)kg

• Electrochemical equivalent of protector material 3,95 kg/А*year

(for magnesium anode)

• Zinc Anodes 12,7mm х 14,3mm standard Standard Size 0.893kg/m

1,05V; 353A-h/lb or 237,31 A-h/ kg

6. CP CALCULATION BASIS – DEFINES INPUT PARAMETERS

6.1 Design methods / standards for CP calculation

GOST 9.602-2005 Uniform protection system against corrosion and ageing.

Underground structures. General requirements for corrosion protection

RD 153-39.4-091-01 Instruction for corrosion protection of municipal piping systems

VSN 009-88 Addendum. Cathodic protection of casings on road/railroad crossings

of pipeline

CPM-DU-6018-TCO «Sacrificial Anode Banks for Pipelines»

6.2 Soil resistivity

• For soil resistivity measurements data provided by “Inzhtechservice” company refer to Attachment A.

6.3 Protection criteria (EºC)

In accordance with CPM-DU-6018

-0.950V minimum with reference to Cu/CuSO4

1,200V maximum

6.4 Anode Electrochemical Design Data

• Galvanic anodes CORRPRO 32S5

The anodes supplied by the Client for this installation are as follows:

length is 533 mm and anode diameter is 127 mm (without packaging)

Pre-packed magnesium anode 14.5kg net weight, 1.5 V

1230 А*hour/kg – Theoretical electrochemical capacity

7. CALCULATION REPORT

For calculation report of protected pipeline surface area, protective current required at 20% coating breakdown, current intensity in the protector – pipeline circuit refer to Table 1.

Table 1

Casing #	Diameter, mm	Length, m	Casing surface area, m2	Mean soil resistivity, Ohm*m	Resistance to current spreading R, Ohm	Current intensity in circuit, А	Protective current required, А	Q-ty of anodes Ea/kg
3	St, 325х6	13	13,3	3,14	1,58	0,38	0,027	0,071
	St, 114х5	14	4,653	-			0,009	-/12,5
2	St, 325х6	6	6,12	3,14	1,58	0,38	0,012	0,032
	St,. 114х5	6	2,147				0,004	-/5,36
1	St,. 325х6	40	40,82	9,98	6,26	0,096	0,082	0,85
	St, 114х5	40	14,316				0,0286	-/35,72
G-line sec.	St, 114х5	6,3	2,26	9,98	6,26	0,096	0,0045	0,05
G-line sec.	St, 114х5	155-60= 95м	34	9,98	6,26	0,096	0,068	0,71

8. CONCLUSIONS

In accordance with GOST 9.602-2005 the soil along MP and LP gasline route in DB area has either high or medium corrosive properties towards buried steel structures.

In compliance with VSN 009-89 “Addendum. Cathodic protection of casings on road/railroad crossings of pipelines” the overall number of sacrificial anodes to be installed on a casing should in any circumstances be at least two anodes – one on each end of the casing. Protection of casings with the length more than 40m will require installation of anodes on both sides of each end of the casing.

Based on the calculation report and VSN 009-89 sufficient protection of the casings on HP gasline in TCO DB will be achieved by installation 12 galvanic anodes.

Current intensity available in galvanic anode – casing circuit on the crossings 3 and 2 with low soil resistant properties considerably exceeds protective current demand approximately 10 times, on crossing 1 exceeds 3.5 times.

In order to reduce the available current intensity to the appropriate value it is necessary to incorporate a variable resistor both in the galvanic anode – casing circuit and in the protector-pipe circuit. Otherwise single protector’s design life might be reduced.

9. CALCULATION METHOD FOR CP WITH GALVANIC ANODES

For calculation method refer to RD 153-39.4-091-01, for calculation report to Table

1. Mean soil resistivity

Soil resistivity has been measured from both ends of casings; as mean soil resistivity value shall be accepted any measured soil resistivity value on the area from the end to the middle of the casing for 3 and 2 crossings, adopted by soil resistivity measurements at 1.1 and 1.2

=2,64*0,5+3,64*0,5=3,14 Ohm*m

For crossing 1 and the pipeline, adopted by soil resistivity measurements at 8.1 and 1.2

=16,33*0,5+3,64*0,5=9,98 Ом*м

where:

– soil resistivity (Ohm*m)

– portion of pipeline length

9.2 Resistance to current spreading

RD 153-39.4-091-01 Appendix U. Sacrificial anodes design procedure. Horizontal anodes configuration.

Resistance to current spreading is calculated by using the formula below:

where:

– resistance to anode current spreading

– bond cable resistance

– pipeline input resistance

Since R value is mainly dependant on the resistance to anode current spreading valuethe formula above may be simplified into: (У8)

Resistance to magnesium anode current spreading may be calculated using the following empirical formula: : (У13)

3 crossing

= 0,45*3,14+ 0,17=1,58 Ohm

where:

А and В are numeric factors 0,45 and 0,17 respectively. таблица

crossings 1

= 0,45*9,98+ 0,17=4,66 Ohm

Bond cable resistance is calculated using the below formula:

= 0,0175*28/16=1,6 Ohm

where:

0,0175Оm*mm2/m is bond cable metal (copper) resistance;

28/16 is the bond cable length and cross section.

Thereby we are able to determine the overall resistance to current spreading:

4,66 + 1,6 =6,26 Ohm

3. Current intensity in galvanic anode – pipeline circuit

According to the formula (U1)

3 crossing =0,6/1,58=0,38 А

Where 0.6V - approximate potential differences between the protector and pipe.

3. Pipeline protective current demand

Protective current demand is calculated based on the protective current density required and casing surface area using the following formula:

where:

k – surface factor 0,20

i – current density required (see Assumptions)

S – casing surface area to be protected =

D – casing diameter (m)

L – casing length (m)

3. Single anodes required to protect casings

Crossing 3

0,051/0,38=0,13 pcs

Where:

– protective current required

– current intensity in anode – pipeline circuit

Crossing 2

0,015/0,38=0,04 pcs

Either:

In kg per design period

Crossing 3

=30*3.95*0.027/0.5=6,39 kg 6,39/14,5кг=0,44 pc; choose 2 pcs

- 30 years of design life

- electrochemical equivalent of anode material 3,95 kg/А*year

- protective current required

- use efficiency

Crossing 2

==30*3.95*0.015/0.5=3,56 kg 3,56/14,5кг=0,25 pcs; choose 2 pcs

Crossing 1

=30*3.95*0.068/0.5=16kg 16/14,5кг=1,1pcs; choose 4 pcs in accordance with VSN 009-88

6,3 m gasline section

=30*3.95*0.005/0.5=1,19kg 1,19/14,5кг=0,08 pcs in this case it

is adequate to protect from the current cathodic protection

95 m gasline section

=30*3.95*0.068/0.5=16 kg 16/14,5кг=1,1pcs; choose 4 pcs

6. Design life of a single galvanic anode

Design life of a single galvanic anode is calculated using the below formula:

where:

- galvanic anode weight, kg

- anode current output on a theoretical basis, 1230А*hour/kg

- anode efficiency factor 0,5

- anode utilization factor 0,9

- current intensity in anode – pipe circuit

- hours of anode use per year

10. ATTACHMENT A

Soil Resistivity Measurements Report for the road

crossings in Tengiz DB

СОДЕРЖАНИЕ

1. КРАТКИЙ ОБЗОР

2. СОКРАЩЕНИЯ

3. ЦЕЛЬ РАСЧЕТА

4. МЕТОД РАСЧЕТА

5. ПРЕДПОЛОЖЕНИЯ

6. ОСНОВЫ РАСЧЕТА КЗ – ОПРЕДЕЛЕНИЕ ИСХОДНЫХ ДАННЫХ

7. РЕЗУЛЬТАТЫ РАСЧЕТОВ

8. ЗАКЛЮЧЕНИЯ / ВЫВОДЫ

9. МЕТОДИКА РАСЧЕТА ЗАЩИТЫ ГАЛЬВАНИЧЕСКИМИ АНОДАМИ

10. ПРИЛОЖЕНИЕ А

Измерение уд. сопротивления грунта в районе кожухов дорожных переходов газопровода Базы Бурения