CP_109 Mothballing Pipelines.pdf

TO CP-LIST

Table of Contents Page

1. INTRODUCTION

4

1.1 Scope 4 1.2 Coverage 4 1.3 Terminology 4 1.4 Referenced Documents 5 2. GENERAL REQUIREMENTS

5

3. CRUDE OIL PIPELINE

6

3.1 New Crude Oil Pipelines 6 3.2 In-Service Piggable Crude Oil Pipelines 7 3.3 In-Service Non-Piggable Crude Oil Pipelines

8

4. GAS PIPELINES

9

4.1 New Gas Pipelines 9 4.2 In-Service Piggable Gas Pipelines 9 4.3 In-Service Non-Piggable Gas Pipelines

10

5. WATER PIPELINES

11

5.1 New Water Pipelines 11 5.2 In-Service Piggable Water Pipelines 11 5.3 In-Service Non-Piggable Water Pipelines

12

6. PROCEDURE FOR MOTHBALLING WITH TREATED WATER

13

6.1 Mothballing of Non-Piggable Pipelines & all pipelines to be safely kept for upto 1 month

13

6.2 Mothablling of Piggable Pipelines for Periods Up to 6 Months 14 6.3 Mothballing of Piggable Pipelines for Periods 6-18 Months 16 6.4 Mothballing of Piggable Pipelines for Periods 18 Months - 5 Years 17 6.5 Mothballing of new Pipelines

17

7. PROCEDURE FOR MOTHBALLING WITH CRUDE OIL

18

8. PROCEDURE FOR MOTHBALLING WITH PRODUCED GAS

21

9. MONITORING AND TESTING

21

0 Oct-96 Issued for Implementation

Rev. Date Description / Text Affected

ADMA-OPCO CP - 109 PAGE 2

Standard Form QAD/04/124 Rev. 0 Sheet 1 of 1

TO CP LIST

Table of Contents (Contd) Page 10. CHEMICAL INJECTION REQUIREMENTS

25

10.1 Batch Treatment 25 10.2 Continuous Injection

25

11. COMMISSIONING AND DISPOSAL

26

12. DELIVERY, STORAGE AND HANDLING 28 APPENDICES

A. Mothballing Chemicals & Dosage Rates for Crude Oil Lines 30 B. Mothballing Chemicals & Dosage Rates for Gas Lines 40 C. Mothballing Chemicals & Dosage Rates for Water Lines 50 D. List of Approved Chemicals and Disposal Category 54 E. List of Suitable Typical Cleaning Pigs 55 F. Maximum Flushing Time for Mothballing of Pipelines 56 G. Pipelines Nominal Size and Diameters 57 H. Pipeline Asset Mothballing Report 58 I. Corrosion Inhibitors Batch Size/KM Length for Various Pipeline Diameters 61 J. Referenced Codes & Standards

62

EXCLUSIVE ATTACHMENTS EA-1 Test Procedures for Identification of Chemicals Residual - Procedures for Tros

Chemicals 63

EA-2 Test Procedures for Identification of Chemicals Residual - Procedures for Petrolite Chemicals

79

EA-3 Test Procedures for Identification of Chemicals Residual - Procedures for Ceca Chemicals

84

EA-4 ADNOC Environmental Emissions Guidelines Limits 88 EA-5 Notification Scheme for the Selection of Chemicals for Use Offshore 90 EA-6 Approved Products Safety Data - Tros Chemicals 110 EA-7 Approved Products Safety Data - Petrolite Chemicals 152 EA-8 Approved Products Safety Data - Ceca Chemicals 181





TO CP LIST

1. INTRODUCTION

1.1 Scope

This Code of Practice details the necessary requirements to ensure carbon steel pipelines are protected from internal corrosion under Mothball, or when Non-Operational conditions as defined below is intended for use by ADMA-OPCO only.

1.2 Coverage

1.2.1 This Code of Practice covers the requirements for corrosion and biological inhibition of crude oil, gas and sea water carbon steel pipelines.

1.2.2 This Code of Practice does not cover mothballing of vessels nor tanks. 1.2.3 This document covers the mothballing procedures using treated sea water, dry

oil or produced gas only. It does not cover purging and mothballing by inert gas.

1.2.4 This Code of Practice additionally covers the required corrosion and condition

monitoring for the relevant mothballed facility, chemicals storage and handling, specifications and list of suitable typical pigs for cleaning of pipelines.

1.3 Terminology

a. MOTHBALLING : Methodology for safe keeping of the pipeline to sustain

its integrity and condition for a defined period of time prior to re-entry into service

b. NON-OPERATIONAL : Not in operation c. PIGGABLE : Lines which can be cost effectively pigged irrespective

of whether or not permanent pigging facilities exist d. NON-PIGGABLE : Lines that cannot be pigged due to operational or cost

constraints e. NEW PIPELINES : Lines that are newly installed and not commissioned f. INSERVICE : Lines that have been operational but require to be PIPELINES mothballed or kept safely during non operation.





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1. INTRODUCTION (CONTD)

1.4 Referenced Documents

The latest editions of the Codes, Specifications and drawings listed in Appendix J shall

to the extent specified herein represent part of this Code of Practice. 2. GENERAL REQUIREMENTS

2.1 Pipelines shall be mothballed or made non-operational in accordance with the guidelines in this Section and to the specific procedures identified in the appropriate sections of this Code of Practice.

2.2 This document also outlines the required temporary plant and equipment including

gauging pigs, cleaning pigs, launchers/receivers, pumps, test instruments and fittings necessary for safe keeping of pipelines where it is deemed that pigging can be carried out cost effectively as part of this Code of Practice.

2.3 Where pressure testing and mothballing operations are combined, the specified

requirements of ADMA-OPCO Specification SP-1016 Part 2 are mandatory and must be adhered to.

2.4 The mothballing methodology should ensure that the plant can be re-commissioned in

the shortest possible time by considering the following:- 2.4.1 If any re-conditioning and/or replacement of equipment is necessary these

operations will be identical to the As Built design unless otherwise waived by the plant operating authority.

2.4.2 Removal of major items of equipment for storage offsite during the

mothballing period should be minimised in the interest of expedient operation and cost.

2.4.3 Re-commissioning of mothballed items shall be carried out by the normal site

maintenance and operations workforce wherever possible rather than by a specially mobilised construction team if at all possible.

2.5 Injection of treatment chemicals should be carried out using proper injection facilities

as described and detailed in ADMA-OPCO Drawing No. AD8-STD-M-0015-1. Any deviation must be endorsed by the appropriate technical authority prior to its implementation.

2.6 All chemicals should be added separately without dilution into the system through

separate injection systems.





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2. GENERAL REQUIREMENTSU (CONTD)

2.7 Safe disposal of chemicals as detailed in Section 11 of this document must be

observed before selection of the appropriate chemical treatment and/or disposal of a mothballing medium.

2.8 The recommended brands and dosage rates of the chemicals detailed in Appendices

A to C are based on the responded Chemical Suppliers recommendations. At the time of mothballing other appropriate chemical cocktails may be proposed if they prove more techno-economically cost effective and therefore should be employed provided the concentration/dosage rate are approved by the technical authority and in the case of open disposal meet the requirements of Section 11.

2.9 A pipeline with a tie-in connected to it can be considered piggable if any of the

following measures are satisfied. a. Tie-ins barred at all connection points. b. Subsea valving facilities exist at tie-in. c. Flow in non-barred tie-in is reversed. 2.10 A line may be considered clean or the minimum level of cleanliness achieved if the

quantity of removed deposit by the last hard brushed mechanical pig run is 10% of that removed during the previous run. This criteria is based on current experience and may be revalidated in light of future data collected

3. CRUDE OIL PIPELINES 3.1 New Crude Oil Pipelines 3.1.1 All new pipelines shall be assumed to be piggable. The practice of batch

dosing, using a train of a minimum of two batching pigs to establish a generally corrosion inhibitor film barrier of nominally 100 micron, will be adopted unless otherwise stated as a requirement. Chemical dosing/injection requirements are considered further in Section 10.

3.1.2 Safe keeping of new oil lines may be carried out using either dry crude or

treated sea water depending on the operational requirements. The relevant procedure as detailed hereafter should be followed.

3.1.3 All conditions and requirements noted in this section should be satisfied prior

to applying the relevant mothballing procedure.





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3.1 New Crude Oil Pipelines (Contd)

3.1.4 Tables A.1 and A.4 of Appendix A should be observed for the specified type

of chemicals and batch size as determined by the mothballing medium and period. In general, use of treated seawater can be considered to provide up to three years protection without replenishment, while dry crude oil for time frames greater than this. Actual mothballing medium shall be defined and justified together with the time scale in which the Asset will be mothballed (safe keeping period).

3.1.5 It is normally practicable to utilise the hydrotest fluid for mothballing if the

latter is operationally deemed necessary. 3.1.6 In view of Clause 3.1.5 above, the specified chemical type dosage and

treatment shall be dictated by the safe keeping period.

3.2 In-Service Piggable Crude Oil Pipelines 3.2.1 All conditions noted in this Section should be satisfied prior to adopting the

relevant mothballing procedure. 3.2.2 Irrespective of the number of cleaning runs needed to achieve the required

level of surface cleanliness prior to mothballing, one cleaning run using soft flexible wire bristle steel bodied brush pig should be carried out as the final run prior to mothballing.

3.2.3 The minimum complete cleaning cycle prior to mothballing should comprise of

a poly pig run, 2 hard brush steel bodied mechanical pig runs and soft flexible bristle brush steel bodied pig run.

3.2.4 A line can be considered adequately clean for the final soft bristle steel bodied

pig run if the quantity of removed deposit with the last hard brushed mechanical pig run does not exceed 10% of that removed during the previous run.

3.2.5 List of suitable/typical pig types are attached as Appendix E. 3.2.6 Irrespective of their intended duty, the selected pigs must be suitable to clean

the intended line taking into account the pipeline design such as number and radius of bends, length of pipeline, valving connections, tie-ins if existing, internal bore, size of available (if any) pig receiver and launcher, etc.

3.2.7 The recommended chemical dosage rates and type are as listed in Tables A.2 or

A.5 of Appendix A for the respective pipeline size, mothballing medium and period.





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3.3 In-Service Non-Piggable Crude Oil Pipelines

3.3.1 The use of high density hydrocarbon dissolvers composed of materials with

high surfactant properties for cleaning in service oil lines is not addressed fully in this Code of Practice. Therefore, potential use of chemical removal of hydrocarbons should be considered on a case by case basis. In general, these chemicals shall be considered in instances where mechanical pigging cannot be carried out and where presence of residual hydrocarbon on the pipewall is considered to hinder effective safe keeping of the pipeline in question. They may in certain instances precede mechanical pigging

3.3.2 All in-service oil lines particularly old ones are considered to contain

appreciable quantities of deposits. 3.3.3 All lines should be mothballed ideally with dry crude oil. Use of treated water

for mothballing is not recommended and may only be considered after sound justification to all concerned parties. Dry crude oil is defined as below limit of detection of conventional Basic Salt & Water (BS&W) determination. If wet crude oil is considered its water content should be known by actual measurement and chemical treatment modified accordingly.

3.3.4 It is recommended that a mixture of biocide and corrosion inhibitor is injected.

See Section 10. 3.3.5 The recommended types of chemical and dosage rates are listed in Table A.3 of

Appendix A for mothballing with crude oil.

3.3.6 Special attention must be given to the adequacy of the chemical inhibitor injection facilities for proper dispersion within the mothballing medium. Chemical injection arrangements should be subject to technical review prior to implementation.

3.3.7 Subject to individual review (Clause 3.3.1 above) the use of surfactants may be

required subject to compatibility (nature, polarity and non-interference properties) with the recommended corrosion prevention chemical to be injected for mothballing.

3.3.8 Long term pipeline safe keeping in excess of 12 months may prove detrimental

to the mothballed line integrity through localised corrosion attack. The particular procedure for monitoring in Section 9 should therefore be closely followed to address the line status.





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4. GAS PIPELINES

4.1 New Gas Pipelines For short period safe keeping of up to one month, either dehydrated dry produced

gas or wet gas slug dosed with corrosion inhibitor may be used as the medium instead of treated water to prevent unnecessary operational complications.

4.1.1 All conditions and requirement noted in this section should be satisfied prior to

applying the relevant mothballing procedure. 4.1.2 New gas lines shall be mothballed using treated water unless otherwise

specified by ADMA-OPCO. 4.1.3 It is normally practicable to employ the hydrotest fluid for mothballing. Safe

keeping duration of the pipeline should dictate the chemical treatment. 4.1.4 Tables B.1 and B.4 of Appendix B list the recommended chemical type,

dosage, batch size and concentration for the required mothballing period. See Section 10 for chemical injection requirements.

4.1.5 Mothballing with inert gas such as nitrogen under a positive pressure is not

covered by this Code of Practice. 4.2 In-Service Piggable Gas Pipelines 4.2.1 The requirements and conditions noted in Clauses 4.1.1 through 4.1.5 above

are applicable. 4.2.2 Tables B.2 and B.5 of Appendix B list the recommended chemical type dosage,

batch size and concentration for the required mothballing period. See Section 10 for chemical injection requirements. 4.2.3 All in-service lines should receive one cleaning cycle as detailed in Clauses

3.2.2 through 3.2.6 prior to commencement of safe keeping.





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4.3 In-Service Non-Piggable Gas Pipelines

4.3.1 In-service gas lines are assumed to contain adherent deposited iron sulphide

films. 4.3.2 Non-piggable gas pipelines are common within ADMA-OPCO onshore

processing and treatment facilities. In certain instances insufficient quantities of gas flow prevent proper corrosion inhibitor carry over to long distances. Safe keeping of these pipelines should be considered on a case by case basis.

4.3.3 In view of Clause 4.3.2 above proper dispersion of the injected corrosion

inhibitor by atomisation is deemed necessary in an attempt to achieve the maximum possible internal chemical protection at line end. Similarly it may be necessary to consider process fluid flow considerations in the safe keeping procedure.

4.3.4 The mothballing medium will in all cases be the produced gas slug dosed with

corrosion inhibitor at the dosage rates noted in the respective Sections of Table B.3 of Appendix B, unless hydrotesting of the pipeline is required as part of Scope of Work in which case treated sea water shall be used.

4.3.5 It must be noted that because of the non-piggable nature of these lines

adequate internal protection may not be achieved unless due consideration of flow velocities is made.





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5. WATER PIPELINES

5.1 New Water Pipelines 5.1.1 It is normal practice to utilise the hydrotest treated water medium for

mothballing should the latter be operationally required. 5.1.2 The mothballing medium in all cases will be treated water the treatment for

which will be dictated by the safe keeping period. 5.1.3 In conjunction with Clauses 5.1.1 & 5.1.2 above, the mothballing procedure

inhibitor dosage rate or batch size detailed in Subsection 6.1 and Table C.1 of Appendix C thereafter should be observed prior to hydrotesting.

5.1.4 Table C.1 of Appendix C lists the recommended inhibitor dosage rates or batch

size for the respective mothballing period and procedure. 5.1.5 For mothballing non-piggable new branched lines, the full portion including

the main line should be treated. 5.2 In-Service Piggable Water Pipelines 5.2.1 Conditions and requirements noted hereafter in this section must be satisfied

prior to commencement of the mothballing exercise. 5.2.2 In all cases the mothballing medium will be treated seawater. 5.2.3 Irrespective of the number of cleaning cycles/runs needed to achieve the

required level of surface cleanliness prior to mothballing, a minimum of one cleaning run using soft flexible steel bodied wire bristle brushes pig should be carried out as the final run prior to mothballing.

5.2.4 The minimum complete cleaning cycle should comprise of the following

sequential runs:- - One run using criss-cross poly pig. - One run using bi-directional steel bodied reversible mechanical pig with

hard brushes. - One run using reversible steel bodied mechanical pig with soft flexible wire

bristle brushes.





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5.2 In-Service Piggable Water Pipelines (Contd)

5.2.5 One complete cycle will be considered sufficient if the quantity of deposits

removed by the hard brushes mechanical pig is less than 30% of that removed by the poly pig.

5.2.6 List of selected typical pigs types is given in Appendix E. 5.2.7 Irrespective of their efficiencies, the selected pigs must be suitable to clean the

intended line taking into account the pipeline design such as number and radius of bends, valving connections, tie-ins if exist, internal bore, size of available (if any) pig receiver and launcher, etc.

5.2.8 The recommended dosage rate of chemicals and type are as listed in Table C.2

of Appendix C for the respective line size and mothballing period. 5.2.9 The required monitoring and testing procedure detailed in the respective

clauses of Section 9 must be observed. 5.3 In-Service Non-Piggable Water Pipelines 5.3.1 Non-piggable water injection lines include non-barred tie-ins with no subsea

valving facilities at the tie-in connection and lines on which installation of pigging facilities are operationally impracticable and/or cost prohibitive.

5.3.2 Unless operationally deemed otherwise, mothballing medium shall be by

treated sea water continuously slug dosed with a compatible blend of biocide, oxygen scavenger and corrosion inhibitor as recommended in Table C.3 of Appendix C.

5.3.3 The use of surfactants should be considered in instances where large quantities

of adherent debris are known to exist and should be selected based on nature and polarity so as not to interfere with the recommended corrosion prevention chemicals to be injected for mothballing.

5.3.4 Water soluble based chemicals only shall be used as the mothballing treatment. 5.3.5 Proper injection facilities must be provided for any supplemental additives to

inject in addition to the existing facilities for biocide and oxygen scavenger. See Section 10.





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5.3 In-Service Non-Piggable Water Pipelines (Contd)

5.3.6 Should it be deemed operationally necessary to inject aldehyde based biocides

and oxygen scavenger the latter must be injected at a minimum of 10 metres upstream of the biocide injection point and at optimum dosage rate to avoid adverse interference.

5.3.7 Long term mothballing in excess of 18 months may prove detrimental to the

line integrity. Results of condition monitoring and corrosion monitoring may therefore indicate the necessity for regeneration and/or renewal of the mothballing medium and hence should be closely observed in accordance with the requirements noted in Section 9 hereafter.

6. PROCEDURE FOR MOTHBALLING WITH TREATED WATER Whenever practicable, treated sea water taken from the Complex Sea Water Injection

System downstream of the vacuum tower should be employed to minimise additional chemical treatment.

6.1 Mothballing of Non-Piggable Pipelines & all Pipelines to be Safely kept for Upto

1 Month 6.1.1 This section covers all non-piggable lines and all lines to be safely kept for

periods up to 1 month. 6.1.2 Install injection point for appropriate chemicals and mobilise injection skid to

point of injection if no permanent operational injection facilities exist. 6.1.3 Test for correct injection pressure and dosage rate in accordance with the

required injection rate as noted in the respective Appendices A to C. 6.1.4 Isolate line to be mothballed from the remaining system. 6.1.5 Ensure that all flushing facilities such as flushing chokes etc. at line end

including those of tie-ins (if they exist) are open. 6.1.6 Commence injection of hydrotest/mothballing water and injection of

mothballing chemical(s). 6.1.7 Continuous injection at the chemical treatment dose rates listed in the

appropriate Tables of Appendices A to C should be employed taking into consideration the safe keeping period for the pipeline.





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6.1 Mothballing of Non-Piggable Pipelines & all Pipelines to be Safely kept for Upto

1 Month (Contd) 6.1.8 Injection of treated water and chemicals should be continued until the

recommended mothballing chemical concentration is detected at line end. As a general rule, the estimated quantity of treated water to be injected to achieve the required level of chemical concentration is approximately 120% of that required to fill the line.

6.1.9 Close flushing facilities and any fittings such as sampling points fitted on

facilities. 6.1.10 Supplemental corrosion and condition monitoring is not necessary for periods

upto 3 months. However, it is considered essential for periods in excess of 3 months.

6.2 Mothballing of Piggable Pipelines for Periods up to 6 Months 6.2.1 Clauses 6.2.1 to 6.2.22 covers all piggable water injection, oil and gas lines. 6.2.2 Ensure suitable permanent chemical injection facilities exist or temporary ones

are installed. 6.2.3 Test for correct injection pressure and rate in accordance with the required

injection rate as noted in the respective Appendices A to C. 6.2.4 Isolate line to be mothballed from the remaining system. 6.2.5 Ensure that all flushing facilities such as flushing chokes etc. at line end

including those of the tie-ins (if they exist) are open. 6.2.6 Launch and run a criss-cross poly cleaning pig with chemically treated raw sea

water (the respective chemicals and dosage rates are listed in Appendices A to C).

6.2.7 On receipt of polypig inspect for any possible geometrical damage and report

to Technical Authority. 6.2.8 If the polypig is damaged follow conditional alternative techniques for cleaning

as described in Clauses 6.2.18 to 6.2.22. 6.2.9 If received polypig was not mechanically damaged, launch and run any of the

selected hard brush mechanical pig (listed in Appendix E) using chemically treated raw sea water.





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6.2 Mothballing of Piggable Pipelines for Periods up to 6 Months (Contd)

6.2.10 Continuous injection at the slug dose rates listed in the appropriate Tables of

Appendices A, B or C should be employed. 6.2.11 For each run the quantities of arriving deposits with the pig should be

measured and recovered for scales and debris subsequent analysis as detailed in Section 9.

6.2.12 Once the measured quantity of debris and scales is less than 10% of that

removed during the last pig run, launch and run the soft bristle brush pig using 500 ppm chemically treated raw sea water as the mothballing medium. (Chemical treatment and dosage rates are as recommended in Appendices A to C).

6.2.13 Injection of treated water and chemicals should be continued until the

recommended mothballing chemical concentration is detected at line end. As a general rule, the estimated quantity of treated water to be injected to achieve the required level of chemical concentration is approximately 120% of that required to fill the line.

6.2.14 For water injection lines only, the operationally in use treated water for

injection is to be used for running of the cleaning pigs. 6.2.15 For water injection lines only and where it is operationally and economically

more feasible, the required treated water for mothballing shall be slug dosed at the respective water injection module/header. The in-use treatment chemicals may be employed for this purpose, dosages as advised by the Technical Authority.

6.2.16 At the end of works close flushing facilities and any other facilities such as

sampling points. 6.2.17 Apply the appropriate corrosion and condition monitoring as noted and

detailed in Section 9.

6.2.18 Conditional Alternative to Mechanical Cleaning (To be Verified with the Technical Authority)

a. Where mechanical cleaning is proven economically and/or operationally

not feasible, alternative approved chemical soaking techniques followed by vigorous flushing may replace the requirements noted in Clauses 6.2.6 through 6.2.12 depending on duty.





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6.2.18 Conditional Alternative to Mechanical Cleaning (To be Verified with the

Technical Authority) (Contd)

b. Soaking and flushing cycles should be continued until the quantity of removed debris/scales and deposits are less than 10% of that removed during the previous cycle.

c. Injection treated sea water shall be the medium for flushing. d. Treated sea water with the recommended chemical dosage rate as detailed

in the relevant Appendices shall be the mothballing medium. e. Apply Clauses 6.2.13 to 6.2.17.

6.3 Mothballing of Piggable Pipelines for Periods 6-18 Months 6.3.1 This section applies to all lines noted in Clause 6.2.1 above. 6.3.2 All conditions and requirements detailed in Subsection 6.2 above are

applicable, unless otherwise superseded hereunder. 6.3.3 The chemical dosage rate for the mothballing medium shall be as

recommended in the appropriate tables of Appendices A to C. 6.3.4 For mothballing of water injection lines, the optional conditional

deviations noted in Clause 6.2.18 are not recommended and all efforts should be exerted to include mechanical cleaning by pigging.

6.3.5 For mothballing of piggable crude oil and gas lines in excess of 12 months,

batch treatment between two pigs is recommended as the treatment technique in the following manner.

a. Launch and displace 1st batching pig by the chemical and diluent batch mix

(for batch size refer to the appropriate tables of Appendices A or B). b. Launch and run by treated sea water, the second pig. c. On receipt of the 2nd pig at receiver, isolate line including any sampling

facilities.





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6.4 Mothballing of Piggable Pipelines for Periods 18 Months - 5 Years

6.4.1 This procedure shall apply to all the lines noted in Clause 6.2.1 above. 6.4.2 All conditions and requirements detailed in Subsections 6.2 and 6.3 above are

applicable unless otherwise superseded hereunder. 6.4.3 For all lines, as dictated by monitoring practices (Section 9) or at a maximum

period of 3 years the mothballing medium shall be regenerated by vigorous flushing where applicable with the same mothballing fluid unless otherwise waived in the corrosion and condition monitoring report.

6.4.4 Where treated water is the mothballing medium, flushing may be carried out

with normal injection quality treated water. 6.4.5 The required testing and analysis as defined in Section 9 during flushing must

be observed closely. 6.4.6 Refill line with the same mothballing medium by observing the recommended

chemical dosage rates in the appropriate tables of Appendices A to C unless an alternative treatment and or chemical dosage rate is advised in the corrosion and condition monitoring report.

6.5 Mothballing of New Pipelines 6.5.1 This Section assumes that all new lines are piggable lines. 6.5.2 Isolate pipeline to be mothballed from remaining system. 6.5.3 Launch and displace 1st batching pig by the chemical and diluent batch mix

(for batch size refer to the appropriate tables of Appendices A to C). 6.5.4 Launch and run by treated sea water, the second pig. 6.5.5 On receipt of the 2nd pig at receiver, isolate line including any sampling

facilities.





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7. PROCEDURE FOR MOTHBALLING WITH CRUDE OIL

7.1 This procedure applies only to crude oil lines 7.2 Non-Piggable Oil Pipelines 7.2.1 Where possible dry crude is recommended to be the mothballing medium. 7.2.2 Check that proper chemical injection facilities exists. Mobilise temporary

injection skid if permanent facilities are not available. Injection point must be equipped with proper injection facilities as detailed in ADMA-OPCO Drawing No. AD8-STD-M-0015-1. Each treatment chemical should be added separately into the system.

7.2.3 For periods in excess of 1 month, mobilise test vessel at line end if back flow is

necessary to produce dry crude. 7.2.4 The relevant operating parameters such as well conditions, flow rates,

operating pressures, etc. will be defined by Production Operation as appropriate and should be recorded.

7.2.5 Flow crude through the line. 7.2.6 Monitor BS & W until 0% water cut is achieved. 7.2.7 Commence inhibitor chemical injection at the rate shown in the appropriate

Table of Appendix A. 7.2.8 Monitor corrosion inhibitor concentration at line end. If this proves impractical

continue flow until 120% of the quantity required to fill the line is injected. 7.2.9 When line is fully mothballed, depressurize line to a positive pressure of

maximum 50 psi. 7.2.10 For mothballing periods in excess of 1 month, the relevant monitoring and

testing procedures detailed in Section 9 shall be observed.





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7.2 Non-Piggable Oil Pipelines (Contd)

7.2.11 Depending on the recommendation to be made in the corrosion and condition

monitoring reports, mothballing medium replacement may be required for periods in excess of 12 months.

Note: For mothballing periods in excess of 6 months, the option of line chemical

cleaning prior to mothballing should be considered on a case by case basis as per Clause 6.2.18.

7.3 Piggable Crude Oil Pipelines 7.3.1 This Section covers Clauses 7.3.2 to 7.3.17 inclusive. For mothballing period of

less than 1 month, pigging and cleaning may not be cost effective and hence could be waived. The same procedure detailed in Subsection 7.2 above may therefore be applied for these periods of mothballing.

7.3.2 For mothballing periods in excess of 1 month the following clauses apply to

piggable crude oil pipeline. 7.3.3 If no permanent chemical injection facilities exist, mobilise temporary chemical

injection skid. 7.3.4 All efforts must be exerted to ensure presence of proper chemical injection

points with a suitable quill for adequate dispersion of the chemical. Each chemical shall be added separately into the system. Alternative chemical injection arrangements subject to Technical Authority approval.

7.3.5 For mothballing periods in excess of 6 months, if Clauses 7.3.3 and 7.3.4

cannot be satisfied, batching of chemicals between two batching pigs shall be the method to adopt for inhibition against corrosion followed by the inhibited fluids. Chemicals inhibition requirements for the batch and driver fluid are contained in Appendices A to C inc.

7.3.6 Launch and run a bi-directional criss-cross poly pig with treated crude oil, as

specified in Table A.1 of Appendix A. 7.3.7 On receipt of the criss-cross poly pig, inspect pig for any possible geometrical

damage.





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7.3 Piggable Crude Oil Pipelines (Contd)

7.3.8 If the pig indicates the presence of possible line geometrical irregularities report

to Technical Authority. 7.3.9 If the poly pig run indicates clear pig passage launch and run a hard brush

mechanical pig driven by chemically treated crude oil as defined in Appendices A to C.

7.3.10 On receipt of brush pig assess and record quantity of scale removed as defined

in Section 9. 7.3.11 If the quantity of scale is less than 30% of that removed by the poly pig, launch

soft bristle pig as in Clause 7.3.13. 7.3.12 If the quantity of removed scale is more than 30%, carry out another

mechanical pig run until the removed scale is less than 10% of that removed during the last mechanical pig run.

7.3.13 Launch and run a soft bristle brush pig driven by chemically treated crude oil.

Continue dosing with chemicals until the correct concentration is attained at line end. In general the pipeline should pass at least 120% of the theoretical volume to fill the line.

7.3.14 Isolate line and all sampling etc. facilities and maintain pipeline at a minimum

positive pressure of 50 psi. 7.3.15 The necessary corrosion and condition monitoring requirements as detailed in

Section 9 shall be observed.

7.3.16 Optional Clauses The following clauses replace Clauses 7.3.9 through 7.3.15 and may apply in

instance where geometrical damage has occurred and (Clause 7.3.7 above) where debris removal is deemed paramount.

a. Launch and run gel pigs (to be defined) until line is clean followed by the

appropriate batch chemical treatment between two gel pigs. (Refer to Appendix A).

b. On receipt of the second gel pig, isolate line and conduct the necessary

corrosion and condition monitoring as detailed in Section 9.





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8. PROCEDURE FOR MOTHBALLING WITH PRODUCED GAS

8.1 This procedure covers all non-piggable gas lines and all gas lines to be mothballed for

safe keeping. 8.2 If no suitable permanent injection facilities exist mobilise a suitable chemical injection

skid to point of injection, ensuring that proper chemical injection facilities with provision for corrosion inhibitor atomisation are made available. Chemical injection system is subject to technical authority approval.

8.3 Test for correct injection pressure and rate in accordance with the required dosage rate

noted in the appropriate Table of Appendix B. 8.4 Commence injection of gas treated with corrosion inhibitor as defined in Table B.3 of

Appendix B and Subsection 10.2. Inhibitor should be added for a period equivalent to displacing 3 pipeline volumes.

8.5 Isolate line to be mothballed for safe keeping from the system maintaining a minimum

pressure of 50 psi in the pipeline. 8.6 Corrosion and condition monitoring is mandatory for all mothballing periods and shall

be closely adhered to as defined in Section 9. 9. MONITORING AND TESTING 9.1 Mothballing with Treated Water for Periods 3 Months and Above 9.1.1 The time of arrival of the mothballing chemical slug should be calculated. 9.1.2 A minimum of three 500ml water samples at 30 minutes interval, shall be taken

starting at one hour prior to theoretical slug arrival for laboratory analysis (chemical concentration) and microbiological counts. Thereafter sampled at 2 minutes intervals and analysed for chemical residuals until the required mothballing chemical concentration level is reached. (Refer to Exclusive Attachments EA-1, EA-2 & EA-3).

Note:- Chemical Vendor should supply or validate residual chemical determination methods. An alternative but less accurate option to determine the level of chemical concentration will be by adding a known concentration of dye material and visually observe water colouration supported by colourometrical analysis using a spectrometer.





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9.1 Mothballing with Treated Water for Periods 3 Months and Above (Contd)

9.1.3 Close flushing choke and all other sampling points etc. and isolate line. 9.1.4 Renew any existing corrosion monitoring coupons at the end of the line to be

mothballed. If E/R probes exist do not replace. Continue to take readings as usual noting mothballing commencement date and chemical treatment utilised.

9.1.5 If a bioprobe exists renew at least one stud (preferably two). 9.1.6 Using the Rapid Check II kit, measure and record the sulphate reducing

bacteria activity on the removed stud(s). Dissolved oxygen determination utilising Chemets shall apply to water at inlet and outlet.

9.1.7 Pipeline isolation shall be carried out once water quantity greater than 115% of

pipeline volume has been passed in accordance with the following formulae:- t = (F D) 2 L) 1.15 = 5.271 x 10 3 (FD) 2 L V4 V Where t = Total time taken to fill the line and flush 15% of line volume

(min) D = External pipeline diameter (In) (e.g. 12 pipe = 12.75) L = Pipeline length (km) V = Volumetric flow rate (bbls/day) F = Correction factor for scaling A 10% nominal reduction in pipeline diameter due to scaling is assumed for up

to 10 diameter pipelines and 5% for larger diameter radials. Appendix F lists the estimated times in min/km for line sizes 6 - 24 at various

flow rates. Also for ease of reference Appendix G lists the nominal pipelines OD sizes.

9.1.8 As appropriate Monitor corrosion rate using weight loss corrosion coupons

and or electrical resistance probes. The latter may be equipped with continuous data logging unit.





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9.1 Mothballing with Treated Water for Periods 3 Months and Above (Contd) 9.1.9 Prepare at least annually corrosion control and condition monitoring report to

include but not be limited to the following details:- a. Pipeline data such as material, pipe dia, route, wall thickness, length. b. Full history of the line. This may be available from other previously

prepared reports on the same line. c. Details of adopted mothballing procedure including intended period, type

of medium, type of treatment chemicals and dosage rate, date of commencement, recommended date for discharge or if necessary replacement of mothballing medium, injection flow rates, pressure and temperature.

d. Details of implemented pigging operation including type of pigs and

brands, number of runs, type and brand of pigging launcher and receiver. e. If pigging operations are carried out, full details of scales and debris

removed including type of scales, weight of scales removed per run, sampling procedures (as defined in the appropriate monitoring and testing clauses), chemical analysis of scales, total weight of scales and debris removed. Time and date of all activities must be recorded.

f. If previous mothballing or pigging operation were carried out on the same

line, the report shall refer to all such activities under separate clause defined as history profile illustrating graphically a comparison chart of nature of scales removed, weight of removed scales, type and number of pigging runs and measured corrosion and condition monitoring data. This will be used as a fine tune guide for future pigging and mothballing operations.

g. Utilised corrosion and condition monitoring methods, their respective

locations, frequency of monitoring, measured corrosion rates and wall thickness and interpretation of recorded data.

h. Tables of all chemical analysis carried out during and after the mothballing

operation including sampling points identification, time and intervals of samples recovery, volume of each sample.

i. Details of any deviation from the specified requirements for mothballing or

testing procedures as defined in this document. The report shall incorporate the justifications for such deviations.

A typical report form is attached as Appendix H.




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9.2 Mothballing with Crude Oil/Gas Medium

9.2.1 The time of arrival of the mothballing chemical slug should be calculated using

the formulae of Clause 9.1.7. 9.2.2 A minimum of three 500ml liquid samples at 30 minutes intervals, shall be

taken starting at one hour prior to theoretical slug arrival for laboratory analysis (chemical concentration). Thereafter sampled at 2 minutes intervals and analysed for chemical residuals until the required mothballing chemical concentration level is reached. (Refer to Exclusive Attachments EA-1, EA-2 & EA-3) validated by the chemical vendor.

9.2.3 Close connected valves and all other sampling points etc. and isolate line,

maintaining a minimum pressure of 50 psi in the pipeline. 9.2.4 Renew any existing corrosion monitoring coupons at the end of the line to be

mothballed. If E/R probes exist do not replace. Continue to take readings as usual noting mothballing commencement date and chemical treatment utilised.

Appendix F lists the estimated times in min/km for line sizes 6" - 24" at various

flow rates. Also for ease of reference Appendix G lists the nominal pipelines OD sizes.

9.2.5 As appropriate monitor corrosion rate using weight loss corrosion coupons and

or electrical resistance probes. The latter may be equipped with continuous data logging unit.

9.2.6 Prepare corrosion control and condition monitoring report in line with the

applicable requirements noted in Clause 9.1.9.





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10. CHEMICAL INJECTION REQUIREMENTS

10.1 Batch Treatment 10.1.1 This section details the requirement to batch chemical treat facilities. 10.1.2 The recommended type of treatment chemicals and approved commercial

brands are tabulated in the relevant tables of Appendices A to C for the respective line duty. Refer to Appendix I for sizing of batch treatment.

10.1.3 All calculated batch sizes were based on neat chemical quantities required to

treat 1 km pipelength with 100 microns thick inhibitor film. The batch sizes also include allowance of 8% for pig and 15% for sphere slipage. Note that for certain products of Appendix B greater thicknesses are specified.

10.1.4 To maximise surface wetting hence efficiency of chemical distribution and

surface coverage, the treatment chemical should always be batched in the form of a 50:50 mix in a suitable diluent. For each recommended chemical type, the respective compatible diluent is recommended by the chemical supplier.

10.1.5 It should be ensured that batch treatment is preferably carried out between a

minimum of two swabbing/batching pigs or alternatively two spheres. 10.1.6 For in service oil and gas lines, batch inhibition must be preceded by

dewatering and desludging of the line to provide maximum surface exposure for treatment.

10.1.7 For used water injection lines, treatment is covered by increasing continuous

addition rates as defined in Subsection 10.2 hereunder. 10.2 Continuous Injection 10.2.1 This section covers the required chemical treatment referred to as continuous

injection in the relevant sections of this document. 10.2.2 The recommended dosage rates for continuous injection are tabulated in the

appropriate Appendices A to C for the respective line duty. 10.2.3 Recommended dosage rates shall be adhered to at all times.





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10.2 Continuous Injection (Contd)

10.2.4 Where injection of the mothballing medium is carried out from a service

vessel, the required mothballing chemical dosage rate shall be calculated as a slug dose and properly mixed with the mothballing medium prior to injection into the line.

Example: To mothball a 1km long pipeline of 10 dia. With a recommended

treatment chemical dosage rate of 500 ppm, the required slug dose = (9.874)2 x 103 x 500 x 1.15 4 x 1550 106 = 28.4 litre say 30 litres 10.2.5 For mothballing water injection lines, slug dosing from the respective water

injection module shall be used including a 20% excess for possible wastage and/or filming out of chemicals as they transport through the pipeline.

Note:- If oxygen scavenger is to be injected separately, the method of injection should

be approved by the technical authority. 11. COMMISSIONING AND DISPOSAL 11.1 This section covers the requirements preceding mothballing for the application of the

necessary corrosion control measures and safe disposal of the mothballing medium. 11.2 Disposal of the mothballing medium (usually water) shall be carried out in accordance

with the applicable safety and environmental control codes and practices (Refer also to Appendix D). Specifically the disposal consents noted in exclusive attachments should be strictly adhered to. Any hydrotest or mothballing chemicals considered outwith this document should be notifiable and disposed of in accordance with UK Dept. of Trade & Industry - safe dopen disposal of offshore chemicals and conform to ADNOC Environmental Guideline limit values, refer to EA-4 & EA-5.

11.3 In general, it is recommended at all times that where permissible the mothballing

medium, irrespective of its nature, is displaced with a dewatering pig or a sphere prior to commissioning/demothballing.





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11.4 Oil and Gas Pipelines

11.4.1 Where the mothballing medium is treated water, it should be displaced by a

train consisting of swabbing pig with a minimum of 4 seal cups followed by an appropriately sized batch of corrosion inhibitor and batching pig. The train to be driven by the normally treated production stream. Requirements of Subsection 11.2 shall apply.

11.4.2 Where oil or gas is the mothballing medium it shall be displaced using the

production stream treated continuously at 3 times the rate of the normally injected continuous dosage rate for 24 hours, unless otherwise advised by the technical authority.

11.4.3 The required data noted in Subsections H.8 through H.10 of Appendix H

(mothballing report) shall be observed and recorded. 11.5 Water Injection Lines 11.5.1 Water injection lines shall be demothballed in accordance with the following:- Displace the mothballing medium with injection quality water. Under normal

conditions no special chemical treatment regime is required for this process. 11.5.2 Observe and record the required data noted in Subsections H.8 through H.10 in

Appendix H (mothballing report).





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12. DELIVERY, STORAGE AND HANDLING

12.1 Delivery The supplied chemicals and diluents if appropriate, shall be supplied in ADMA-OPCO

approved tanks. These Chemicals shall be packaged and labelled in accordance with ADMA-OPCO

Specification SP-1004. Each tank shall be clearly marked with the following:- a. Product Name and Reference; b. Suppliers Name; c. Suppliers Address; d. Suppliers Telephone, Facsimile and Telex Numbers; e. Material Flash Point; f. Hazchem Labels as required by UAE Legislation. 12.2 Documentation for Storage and Handling The Vendor supplied chemicals and diluents shall be accompanied by but not be

limited to the following documents. a. Product Name and Reference; b. Batch Number and Volume; c. Specific Gravity; d. Flash Point; e. Date of Manufacture; f. Date of Despatch; g. Copy of Certificate of Approval for the Tank, Supplied by an Approved Certifying

Authority; h. Viscosity Range over the Temperature Range 0C-70C; i. Requirements for Personnel Protection during Handling; j. First Aid in the Event of Accidental Skin or Eye Contact, or Ingestion; k. Methods of Firefighting; l. Methods of Safely Dealing with Spillages; m. Permitted Concentrations for Discharge to the Sea as Categorised by the UK

Department of Trade and Industry; n. Detailed Safety Data Sheet of the Supplied Chemical(s); o. Step by Step Procedure for Safe Handling and Storage of the Supplied

Chemical(s); p. Completed ADMA-OPCO HSEP Data Sheet.





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12.3 Compliance

a. In addition to satisfying the requirements detailed in Subsections 12.1 and 12.2

above, the Vendor shall also comply with the accompanied commercial conditions and requirements as stated on the purchase order.

b. In addition to satisfying the requirements detailed in Subsections 12.1 and 12.2

above, all concerned parties involved in delivery, handling and storage of the supplied chemicals shall observe ADMA-OPCO General Safety Procedures and Regulations for safe handling and storage of chemicals.





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APPENDIX A

MOTHBALLING CHEMICALS & DOSAGE RATES

FOR CRUDE OIL LINES

TABLE A.1 - DRY OIL MEDIUM - NEW LINES TABLE A.2 - DRY OIL MEDIUM - PIGGABLE LINES TABLE A.3 - DRY OIL MEDIUM - NON-PIGGABLE LINES TABLE A.4 - WATER MEDIUM - NEW LINES TABLE A.5 - WATER MEDIUM - PIGGABLE LINES TABLE A.6 - WATER MEDIUM - NON-PIGGABLE LINES





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APPENDIX B

MOTHBA LLING CHEMICALS & DOSAGE RATES

FOR GAS LINES TABLE B.1 - PRODUCED GAS MEDIUM - NEW LINES TABLE B.2 - PRODUCED GAS MEDIUM - PIGGABLE LINES TABLE B.3 - PRODUCED GAS MEDIUM - NON-PIGGABLE LINES TABLE B.4 - WATER MEDIUM - NEW LINES TABLE B.5 - WATER MEDIUM - PIGGABLE LINES TABLE B.6 - WATER MEDIUM - NON-PIGGABLE LINES





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APPENDIX C

MOTHBALLING CHEMICALS & DOSAGE RATES

FOR WATER LINES TABLE C.1 - WATER MEDIUM NEW LINES TABLE C.2 - WATER MEDIUM PIGGABLE LINES TABLE C.3 - WATER MEDIUM NON-PIGGABLE LINES





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APPENDIX D

LIST OF APPROVED CHEMICALS AND OPEN DISPOSAL CATEGORY

CHEMICAL

NAME

GENERIC

DESCRIPTION

DISPOSAL

CATEGORY

TROS TC 1000 AMMONIUM BISULPHITE OXYGEN SCAVENGER CATEGORY 0

TROS TH 7062A IMIDAZOLINE BASED CORROSION INHIBITOR CATEGORY 2*

TROS TK 460A QUAT. AMINE BASED BIOCIDE/C.INHIBITOR CATEGORY 2*

TROS TK 3406 AMINE/PHOSPHONIUM QUAT BASED BIOCIDE CATEGORY 2*

TROS TK 455 QUAT AMINE/ALDEHYDE BASED BIOCIDE CATEGORY 2*

TROS 650 QUAT AMINE/AMONIUM BISULPHITE BASED

HYDROTEST CHEMICAL

CATEGORY 2

TROS TH 804 POLY ACRYLATE BASED SCALE INHIBITOR CATEGORY 1

TROS CT 3707 IMIDAZOLINE/AMINE BASED CORROSION

INHIBITOR

CATEGORY 2*

TROS C77 MIXED AMINE BASED CORROSION INHIBITOR CATEGORY 1

PETROLITE XC-2809 DIAMINE ACETATE/QUATERNARY BLEND BIOCIDE 3*

PETROLITE KW-2140 QUARTERNARY AMINE CORR. INHIBITOR 3*

PETROLITE WF-2020 DIAMINE ACETATE/AMONIUM BISULPHITE

PYRIDINE QUATERNARY COCKTAIL

3*

PETROLITE KP-2414 IMADAZOLINE CORROSION INHIBITOR 3*

PETROLITE PD-11 COMBINATION OF OXYALKYLATED PHENOL

FORMALDEHYDE RESINS IN HEAVY AROMATIC

NAPTHA

3*

PETROLITE K-490 AMMONIUM BISULPHITE OXYGEN SCAVENGER 1

CECA NO RUST PA 23D FATTY AMINE DERVATIVE CORROSION INHIBITOR N/A

CECA NO RUST 420M FATTY AMINE DERVATIVE CORROSION INHIBITOR 2

CECA NO RUST SC43 AMMONIUM BISULPHITE OXYGEN SCAVENGER 2

CECA NO RUST IG 91C AMIN IN ALCOHOLIC SOLUTION CORR. INHIBITOR N/A

* Anticipated classifications based on similar known classified products. Disposal categories are as defined by the UK Department of Trade & Industry and ADNOC Guidelines (refer

to EA-4 & EA-5). This Appendix should be read in conjunction with Section 11 of this Code of Practice.





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APPENDIX E

LIST OF SUITABLE TYPICAL CLEANING PIGS

MANUFACTURER SUPPLIER PIG TYPE

POLY PIG

HARD WIRE BRUSH/PAD

MECHANICAL PIG

SOFT BRISTLE BRUSH

PIG

KNAPP

CRISSCROSS

BA3 BRD3 STIFF WIRE

BA3 BRD3 LONG THIN WIRE

PIPELINE ENGINEERING

PE WIRE BRUSH

PESP1 SCRAPER FOR WATER LINES. PEUG 1 OR 2 FOR OIL & GAS

SLCS-6 (WITH TWIN CLIP HIGH GRADE S.STEEL BRISTLES

PIPETRONIX

CIRCULAR WIRE BRUSH LT TYPE

M.H. MALONEY

(FOR OIL & GAS ONLY) B1-D1 SL CLEANING OR B1-D1 FLEX MAG

PERRY EQUIPMENT

B5 FOR OIL & GAS C5 FOR WATER

PSRF

KOPP

CIRCULAR WIRE BRUSH LIT TYPE

INTL. PIPELINE

PRODUCTS (INPIPE)

LONG RUN

IPRCN (UPTO 18) OR IPUG 1 OR 2 (FOR OIL & GAS ONLY)

OTHER POTENTIAL PIG SUPPLIERS WHO MAY BE APPROACHED ARE:-

T.D. WILLIAMSON ENDURO PIPELINE NOTE:- 1. POLY PIGS SHOULD IN GENERAL INCLUDE WIRE BRUSHES. 2. ACTUAL PIGS UTILISED SHOULD BE SUBJECT TO APPROVAL OF TECH55NICAL

AUTHORITY.





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APPENDIX F

MAXIMUM FLUSHING TIME

FOR MOTHBALLING OF PIPELINES

Maximum times required to flush pipelines with treated water for mothballing. Times are in minutes per km length of pipeline.

TIMES TO FLUSH PIPELINE PER KM LENGTH (MINUTES)

FLOWRATE NOMINAL PIPELINE DIAMETER (INCH)

(MBWPD) 6 8 10 12 14 24

5 28 50 79 113 155 482

7.5 19 33 53 75 103 322

10 14 25 40 57 77 241

12.5 11 20 32 45 62 193

15 9 17 26 38 52 161

17.5 8 14 23 32 44 138

20 7 12 20 28 39 121

25 6 10 16 23 31 96

30 5 8 13 19 26 80

35 4 7 11 16 22 69

40 4 6 10 14 19 60

45 3 6 9 13 17 54

50 3 5 8 11 15 48

60 2 4 7 9 13 40

70 2 4 6 8 11 34

80 2 3 5 7 10 30

90 2 3 4 6 9 27

Scale Factor: 10% for pipelines with diameters below 14-inch and 5% for 14-inch and above.

To obtain the flushing time required multiply the above times by the length of the pipeline in kilometers. For example for a 5.2 km pipeline of 12-inch diameter for a flow rate of 20,000 barrels of water per day the flushing time is 5.2 x 28 = 146 minutes.





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APPENDIX G

PIPELINES NOMINAL SIZE AND DIAMETERS

NOM. SIZE

(IN)

O.D. (IN)

W.T. (IN)

I.D. (IN)

24 24 0.625 22.75

14 14 0.75 12.5

12 12.75 0.562 11.626

10 10.75 0.465 9.82

8 8.625 0.322 7.981

6 6.625 0.28 6.065

4 4.5 0.237 4.026





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APPENDIX H

PIPELINE ASSET MOTHBALLING REPORT

H.1 LOCATION & IDENTIFICATION 1. Pipeline Win No. : 2. Field : 3. Line Name : 4. Route : H.2 SPECIFICATION DATA 5. Size : 6. Length : 7. Grade : 8. Wall Thickness : H.3 OPERATIONAL HISTORY 9. Date of Installation : 10. Date of Commissioning : 11. Hydrotest Fluid : 12. Hydrotest Chemical : 13. Duty : 14. Pressure & Temp. : H.4 STREAM NATURE/OPERATING CONDITIONS 15. Oil, Gas or Water : 16. Sour ? : Yes ( ) No ( ) 17. Wet ? : Yes ( ) No ( ) 18. H2S Level : MOL % ( ) N/A ( ) 19. Water Cut : % ( ) N/A ( ) 20. CO2 Level : MOL % ( ) N/A ( ) 21. Operating Pressure : 22. Operating Temp. : H.5 MOTHBALLING & PIGGING PROFILE 23. Is Line Previously Mothballed : Yes ( ) No ( ) 24. Medium : 25. Chemicals : 26. Concentration :





Sheet: 1 of 3

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APPENDIX H


27. Duration & Date of Initial : Mothballing 28. Chemical Analysis Carried : Out (Attach if yes) 29. Has Line been Pigged or Flushed : Pigged ( ) Flushed ( ) No ( ) prior to Mothballing 30. No. of Pigging Cycles : 31. No. of Runs per Cycle : 32. Type of Pigs Used : 33. No. of Pigs Used per Cycle : 34. Measured Corrosion Rates : 35. If Flushed or Pigged State Quantity of Debris Recovered per run and nature of

debris as follows:- Cycle/Run No. Quantity & *Nature Date/Time Note: *Attach Chemical Analysis 36. Type of Corr. Monitoring : 37. No. of Points : 38. Location : H.6 MOTHBALLING PROCEDURE LOG 39. Mothballing Period & : Starting Date 40. Medium : 41. Is Line Piggable : 42. Pre-Mothballing Cleaning : ( ) Flushing ( ) Pigging If Flushing: 43. Recorded Quantity of Flushing : Water 44. Quantity of Removed Debris : 45. No. of Flushing Cycles : If Pigging: 46. No. of Runs : 47. Type of Pigs :





Sheet: 2 of 3

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APPENDIX H


48. Quantity of Debris/Scales : Recorded per Run/*Nature Run No. Type of Pig Qty & * Nature Date/Time Note: *Attach Chemical Analysis Mothballing Chemicals 49. Type of Chemicals : 50. Mode of Injection - ( ) Continuous ( ) Batch ( ) Both 51. Dosage Rate/Batch Size : 52. Date/Time of Injection : 53. Sampling Point Location : 54. Sampling Intervals, : Date & Time of 1st Sample Sampling Period Inhibitor Residual Level Flow Rate H.7 CORROSION & CONDITION MONITORING DURING MOTHBALLING 55. Recorded Temp. & Pressure : 56. Corrosion Monitoring Data: Date Corr. Rate Bacterial Counts Device Type Water Chemistry





Sheet: 3 of 3

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APPENDIX I

CORROSION INHIBITORS BATCH SIZE/KM LENGTH

FOR VARIOUS PIPELINE DIAMETERS

Based on 100 MICRONS (0.004") Film Thickness of Inhibitor in 50:50 mix with Diluent Batch Size = P1 () DLT where; D - Pipeline Diameter, L = 1 Km Length, T = Inhibitor Film Thickness

PIPELINE DIA. BATCH SIZE/1 KM 6 12.9 8 17.1 10 21.4 12 25.7 14 30.0 16 34.3 18 38.6 20 42.8 22 47.1 24 51.4 26 55.7 28 60.0 30 64.3 32 68.5 34 72.8 36 77.1 38 81.4 40 85.7 42 90.0 44 94.2 46 98.5 48 102.8 52 11.14





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APPENDIX J

REFERENCED CODES & STANDARDS

The latest editions of the Codes, Specifications and drawings listed below shall to the extent specified herein represent part of this Code of Practice. DTI UK Department of Trade and Industry classification for

chemicals safe disposal - Offshore Chemical Notification Scheme

ADMA-OPCO SP-1004 Specification for Packaging & Labelling of Dangerous

Substances SP-1016 Part 2 Specification for Hydrostatic Testing of Subsea Pipelines Drawing No. AD8-STD-M-0015-1 Chemical Injection Point Valve Support G.A and Details.

ADMA-OPCO Safety Regulations





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EA - 1

TEST PROCEDURES FOR IDENTIFICATION OF

CHEMICALS RESIDUAL

PROCEDURES FOR TROS CHEMICALS





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EA - 2


CHEMICALS RESIDUAL

PROCEDURES FOR PETROLITE CHEMICALS





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EA - 3


CHEMICALS RESIDUAL

PROCEDURES FOR CECA CHEMICALS





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EA - 4

ADNOC ENVIRONMENTAL EMISSION GUIDELINES LIMITS





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EA - 5

NOTIFICATION SCHEME FOR THE SELECTION

OF CHEMICALS FOR USE OFFSHORE





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EA - 6

APPROVED PRODUCTS SAFETY DATA

TROS CHEMICALS

PRODUCT TITLE

Troskil 1 Biocide

Tro TK-460 Biocide

Troskil 3406 Biocide

Tros C 70 Corrosion Inhibitor

Tros TH-7062 A Corrosion Inhibitor

Tros TC 1000 Oxygen Scavenger

Tros Sea Dye

Tros 650 Combination Hydrotest Product





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EA - 7


PETROLITE CHEMICALS

PRODUCT TITLE

KW 2140 Corrosion Inhibitor

K 490 Oxygen Scavenger

WF 2020 Hydrostatic Test Chemical

KP 2414 Corrosion Inhibitor





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EA - 8


CECA CHEMICALS

PRODUCT TITLE

Norust IG 91 C Corrosion Inhibitor

Norust PA 23 D Corrosion Inhibitor

Norust 420 M Corrosion Inhibitor





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CP_109 rev 0.pdfFront SheetTable of Contents1-Introduction2-General Requirements3-Crude Oil Pipelines4-Gas Pipelines5-Water Pipelines6-Procedure for Mothballing with treated water7-Procedure for Mothballing with crude oil8-Procedure for Mothballing with produced gas9-Monitoring & Testing10-Chemical Injection Requirements11-Commissioning & Disposal12-Delivery, Storage & HandlingAppendicesAppendix AAppendix BAppendix CAppendix DAppendix EAppendix FAppendix GAppendix HAppendix IAppendix J

AttachmentsEA-IEA-2EA-3EA-4EA-5EA-6EA-7EA-8

CP_109 Mothballing Pipelines.pdf

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