GP 10-01 - Casing and Tubing Design - 0900a866802a6d4a

Document No.

GP 10-01

Applicability

Group

Date

9 July 2008

GP 10-01

Casing and Tubing Design

Group Practice

BP GROUP ENGINEERING TECHNICAL PRACTICES

9 July 2008

GP 10-01 Casing and Tubing Design

Introduction The introduction to this ETP mirrors section 13 of the revised DWOP. All Casing and Tubing design activity shall conform to Engineering Technical Practice GP10-01 Casing & Tubing Design 1

Design

1.1

All casing and tubing designs shall be addressed in a well basis of design document. If that document is field-wide, a separate document shall, when appropriate, stipulate where a specific well design deviates from the field-wide basis of design.

1.2

A casing and tubing design shall be performed for all wells and should incorporate foreseeable life-of-well requirements and abandonment. Where wells are to be produced, tested, stimulated, injected or modified, a design check shall be performed for the existing configuration, unless as part of the SPU assurance process a previous design is demonstrated to be adequate. Design Standard

1.3

The requirements contained within the BP Tubular Design Manual (BPA-D-003) shall be applied for both the tubing and casing program basis of design. The basis of design will address parameters within which it is acceptable to plan further wells in a programme, campaign or area without further detailed design. When these parameters are exceeded, a detailed reassessment of the design is required. Tools and Design Data

1.4

Casing and tubing design shall be performed using the BP approved casing design software and methods as identified in the BP Tubular Design Manual. Exceptions shall be subject to EPT review.

1.5

Every tubular component in the load path or forming part of the pressure envelope shall be traceable per API, ISO, and/or BP specifications and verified either by reference to the mill certificates or mechanical testing to have the expected mechanical performance. Every component shall also be in good condition, and all equipment should be suitable for expected service life.

1.6

Casing and tubing design software are safety critical.

1.7

Casing and tubing designs shall be subject to assurance review as a minimum shown in Table 1 in this ETP.

1.8

A minimum set of design loads, including setting depth, burst, collapse, tension and triaxial considerations for both the tube body and connection, is defined in the BP Tubular Design Manual. Designs governed by loads outside those listed in the BP Tubular Design Manual shall be subject to review as in Well Category 3 in Table 1. 1. All casing and liners shall be designed to withstand reasonably foreseeable well control burst loadings. The starting point for well control burst loading shall be gas to surface from casing shoe, or lower open hole fracture pressure. Casing designs using lesser well control loadings not appearing in the BP Tubular Design Manual as acceptable alternatives shall be subject to review as per Well Category 2 in Table 1. 2. Casing designs shall include definition of the well control scenarios they accommodate and their rationale based on subsurface information, local experience and operational well Page 2 of 14

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GP 10-01 Casing and Tubing Design

control capabilities. Kick intensities for well design shall be based on appropriate and prudent application of pore pressure uncertainty as described in GP 10-15 Group Practice on Pore Pressure Prediction. 3. All production casing and liners shall be designed for burst, to withstand the maximum pressure resulting from a tubing leak at the wellhead applied over the packer fluid Design factors 1.9

The minimum acceptable design factors for BP tubular design calculations are given in Table 2.

2

Procurement Standard

2.1

Casing and tubing shall be manufactured, inspected and tested in accordance with the standards as outlined in the ETP 10-01 Qualifying Materials Sour and/or Corrosive Service

2.2

The materials selection process for wells expected to contain H 2S shall comply with NACE MR0175/ISO 15156. Only seamless grades of tubulars are acceptable for casing and tubing which may be exposed to H2S/sour environments as defined in NACE MR0175/ISO 15156.

2.3

The materials selection process for production tubulars expected to contain CO 2 and/or H2S shall follow the requirements of BP EPT Guidance Note GN 036-13. In case of a conflict between this document and NACE MR0175/ISO 15156, the more onerous requirement shall govern. Alteration of Specification Properties

2.4

Field welding of tubulars is permitted on API Spec 5L/ISO 3183 grade line pipe and API Spec 5CT/ISO 11960 Grade K55 tubulars, and shall conform to the guidelines laid out in API RP 5C1/ISO 10405. Welding operations on other grades of pipe will require specific qualifications and procedures per GP 18-01. Well-site Inspection

2.5

All casing, tubing and handling tubulars shall be visually inspected and drift tested as close to the point of use as practical to identify handling damage to the pipe body and threaded connections that could present problems during installation and/or over the life of the well.

3

Operation Loads

3.1

Operations during installation and well life shall not exceed the loads under which exposed tubulars have been designed. A revised design evaluation shall be completed, should such an occurrence be contemplated. Setting Depths 3.2

Casing and liner setting depths shall be selected to provide a sufficient safety margin between formation fracture pressure and well control and/or casing cementing operations. Limitations on allowable well control operations shall be detailed in the design.

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GP 10-01 Casing and Tubing Design

Foreword This is the first issue of Engineering Technical Practice (ETP) BP 10-01 dealing with Casing & Tubing Design. This Group Practice (GP) replaces the relevant parts of the Drilling and Well Operations Policy BPA-D-01.

Copyright © 2008 BP International Ltd. All rights reserved. This document and any data or information generated from its use are classified, as a minimum, BP Internal. Distribution is intended for BP authorized recipients only. The information contained in this document is subject to the terms and conditions of the agreement or contract under which this document was supplied to the recipient's organization. None of the information contained in this document shall be disclosed outside the recipient's own organization, unless the terms of such agreement or contract expressly allow, or unless disclosure is required by law. In the event of a conflict between this document and a relevant law or regulation, the relevant law or regulation shall be followed. If the document creates a higher obligation, it shall be followed as long as this also achieves full compliance with the law or regulation.

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GP 10-01 Casing and Tubing Design

Table of Contents Page 1.

Scope...................................................................................................................................... 6

2.

Normative references.............................................................................................................. 6

3.

Terms and definitions.............................................................................................................. 8

4.

Symbols and abbreviations.....................................................................................................8

5.

General................................................................................................................................... 9 5.1. Introduction.................................................................................................................. 9 5.2. Application.................................................................................................................... 9 5.3. Implementation............................................................................................................. 9 5.4. Revision....................................................................................................................... 9 5.5. Exceptions.................................................................................................................... 9

6.

Design................................................................................................................................... 10 6.1. Application..................................................................................................................10 6.2. Design standard.........................................................................................................10 6.3. Tools and design data................................................................................................10 6.4. Review....................................................................................................................... 10 6.5. Design loads............................................................................................................... 11 6.6. Design factors............................................................................................................. 11

7.

Procurement.......................................................................................................................... 12 7.1. Standard..................................................................................................................... 12 7.2. Qualifying materials....................................................................................................12 7.3. Well-site inspection....................................................................................................13

8.

Operation.............................................................................................................................. 13 8.1. Loads......................................................................................................................... 13 8.2. Setting depths............................................................................................................ 13 8.3. Float equipment.........................................................................................................13

9.

Abandonment........................................................................................................................ 13

List of Tables Table 1 – Required Well Design Review Level...............................................................................11 Table 2 – Minimum Casing and Tubing Design Factors..................................................................12

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1.

GP 10-01 Casing and Tubing Design

Scope This Group Practice (GP) provides guidance for the specification and design of the tubular components to contain the pressure envelope of the well during its construction, life-cycle and abandonment. These components include the casing and production tubing and connections. This GP references the mechanical load scenarios that should be addressed and the minimum design factors that should be applied during the design phase. Additional requirements consider handling operations, tubular interaction with wellbore fluids (erosion, corrosion and other materials issues), foreign or environmental substances (thread compound, air and sea-water) and non-conventional loads (mobile formations). This GP also details reference standards and requirements that constitute the minimum level of acceptability for a BP tubular component. Other well components required to contain the pressure envelope, such as fluids, Christmas tree, wellhead, Blowout Preventer (BOP), annular isolation and packers, are not covered in this document. Non-Oil Country Tubular Goods (OCTG) components of the wellbore are covered in the Group Practice for Engineered Equipment, GP 10-50.

2.

Normative references The following normative documents contain requirements that, through reference in this text, constitute requirements of this technical practice. Requirements found in any documents not referenced, herein and/or below, are not requirements of this technical practice. For example, Clause 5.3 requires all appropriate personnel to be knowledgeable of the elements of this GP related to their work activities. This is not meant to imply, per the statement above, that personnel should be knowledgeable of unreferenced material in the normative references listed in this clause. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this technical practice are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.

BP BPA-D-002 BPA-D-003 BP EPT GN 036-13 BP-EPT-IAS-02 GIS 10-001 GIS 10-002 GIS 10-003 GIS 10-004 GIS 10-006

BP Well Control Manual BP Tubular Design Manual Guidance Note: Guidelines for selection of downhole tubing and casing materials for oil and gas production wells Integrity Assurance Specification (IAS) for the Procurement of Tubular Products and Connection Manufacturing Services (for Use in Wells) Specification for OCTG Seamless Casing and Tubing Specification for OCTG EW Casing Specification for OCTG Crossover Connectors Specification for Sour Service Grades C110 and C125 Low Alloy Steel OCTG Seamless Pipe Specification for Duplex and Super Duplex 25% Chrome Stainless Steel Seamless Pipe

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GP 10-01 Casing and Tubing Design

GIS 10-007 GIS 10-010 GIS 10-011 GP 00-01 GP 00-10 GP 10-15 GP 10-50 GP 10-60 GP 18-01 DWGOM-GIS 80-0050 DWGOM-GIS 80-0060 DWGOM-GIS 80-0070 DWGOM-GIS 80-0080 DWGOM-GIS 80-0090 DWGOM-GIS 80-0100 DWGOM-GIS 80-0110

Guidance Document for the Handling, Transportation and Storage of Casing & Tubing (OCTG) Guidance Document for Running and Handling of Corrosion Resistant Alloy (CRA), Casing & Tubing (OCTG) at Rig Site Guidance Document for Running and Handling of Low Alloy Carbon Steel (LACS), Casing & Tubing (OCTG) at Rig Site ETP Introduction Guide for Engineers Developing Engineering Technical Practices (ETPs) Group Practice on Pore Pressure Prediction Group Practice for Engineered Equipment Group Practice for Suspension, Abandonment and Zonal Isolation Guidance on Practice for Welded Fabrication and Construction Weld Fatigue Qualification Specification for High Capacity-High Fatigue Drilling Conductor Paint Specification for High Capacity/High Fatigue Drilling Conductor Components Line Pipe Specification for High Capacity/High Fatigue Drilling Conductor (Deepwater Development – GOM) Grinding Specification for Fatigue Life Enhancement of Line Pipe Girth Welds on High Capacity/High Fatigue Drilling Conductor Forging Specification for High Capacity/High Fatigue Drilling Conductor Fabrication Specification for High Capacity/High Fatigue Drilling Conductor Welding Specification for High Capacity/High Fatigue Drilling Conductor

Industry Standards API RP 5C1 API Specification 5CT API Specification 5L ISO 3183 ISO 10405 ISO 11960 ISO 15156-1

ISO 15156-2

ISO 15156-3

NACE MR0175

Recommended Practice (RP) for Care and Use of Casing and Tubing Specification for Casing and Tubing Specification for Line Pipe Petroleum and natural gas industries – Steel pipe for pipeline transportation systems Petroleum and natural gas industries — Care and use of casing and tubing Petroleum and natural gas industries — Steel pipes for use as casing or tubing for wells Petroleum and natural gas industries — Materials for use in H2Scontaining environments in oil and gas production — Part 1 : general principles for selection of cracking-resistant materials Petroleum and natural gas industries — Materials for use in H2Scontaining environments in oil and gas production — Part 2 : crackingresistant carbon and low alloy steels, and the use of cast irons Petroleum and natural gas industries — Materials for use in H2Scontaining environments in oil and gas production — Part 3 : crackingresistant CRAs (corrosion-resistant alloys) and other alloys Petroleum and natural gas industries — Materials for use in H2Scontaining environments in oil and gas production, See also ISO 15156

Useful information on tubular design can be found at the Tubular Technology website, http://octgdesign.bpweb.bp.com/. A number of the references listed above

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GP 10-01 Casing and Tubing Design

can be located at the technical practices portal, http://technical_practices.bpweb.bp.com/. Informative, related documents include the DWGOM-GIS 80-0050 through DWGOM-GIS 80-0110 series listed above which addresses drilling conductors and connectors for the offshore environment. The final clause of this GP also contains a Bibliography. Documents listed in the Bibliography appear for information only as an aid to the interested reader.

3.

Terms and definitions For the purposes of this GP, the following terms and definitions apply: Barrier Envelope of one or several dependent barrier elements preventing fluids from flowing unintentionally from the formation into another formation or to the surface Casing One of several pressure and load bearing tubulars used to construct a well Jewellery All non-OCTG components used in a casing, liner or tubing string which form part of the load bearing or pressure retaining envelope, e.g. crossovers, packers, gas lift mandrels, hangers, running tools Liner A casing string that is not landed in the wellhead Safety critical data Information necessary to reproduce the design process for an aspect of well construction deemed to be capable of resulting in major accident risk Scab liner Tubular string installed inside a casing string, typically to re-establish pressure containment following problems with the original casing Tubing The innermost tubular string that serves as a conduit for reservoir fluids and/or injection fluids Well category # A determination of the technical level at which a well review will be conducted.

4.

Symbols and abbreviations For the purpose of this GP, the following symbols and abbreviations apply: APB

Annular pressure build-up

BOP

Blow-out preventer

CRA

Corrosion Resistant Alloy

EPT

Exploration and Production Technology

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5. 5.1.

GP 10-01 Casing and Tubing Design

ETP

Engineering Technical Practice

GP

Group Practice

LACS

Low Alloy Carbon Steel

OCTG

Oil Country Tubular Goods (e.g. casing and tubing)

RP

Recommended Practice (Generally API)

SBHT

Static bottom hole temperature

SITHP

Shut-in tubing head pressure

SPU

Strategic Performance Unit

General Introduction BP is committed to conducting its business in a manner which ensures that wells are designed, drilled, completed and maintained to high and consistent standards. BP’s minimum well tubular standards are defined in this GP. BP will comply with all relevant laws and regulations, and will be sensitive to the balanced economic and environmental needs of the community. Sound engineering judgement and governmental regulations may require that operations be carried out to standards exceeding those contained in this GP.

5.2.

Application This GP applies to all tubular design and handling operations associated with well construction, drilling, testing, completion, workover and intervention activities related to wells performed under the control or supervision of BP, or on behalf of BP as the operator. For running and handling guidelines, see GIS 10-007, GIS 10-010 and GIS 10-011. The GIS series of documents supplement API and ISO standards, bulletins and recommended practices to accommodate additional requirements by BP that exceed international requirements. See also Clause 7.1 for a list of the applicable standards for OCTG procurement.

5.3.

Implementation All staff and contractor personnel engaged in OCTG design or managing inspection and installation operations and intervention well work shall be knowledgeable of the elements of this GP related to their work activities and are responsible for compliance. See the explanatory comment in Clause 2 for the relation between this requirement and the normative references.

5.4.

Revision The revision procedure for this document adheres to GP 00-01.

5.5.

Exceptions Deviations from this GP shall only be considered in exceptional circumstances. The procedure and accountabilities for deviations is detailed in GP 00-01.

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6. 6.1.

GP 10-01 Casing and Tubing Design

Design Application All casing and tubing designs shall be addressed in a well basis of design document. If that document is field-wide, a separate document shall, when appropriate, stipulate where a specific well design deviates from the field-wide basis of design. A casing and tubing design shall be performed for all wells and should incorporate foreseeable life-of-well requirements and abandonment. Where wells are to be produced, tested, stimulated, injected or modified, a design check shall be performed for the existing configuration, unless as part of the SPU assurance process a previous design is demonstrated to be adequate. Use of a portion of an existing wellbore to recomplete a well in another hydrocarbon bearing zone constitutes a modification and requires a design check. A design check differs from a design review (see Table 1). A design check is performed by the responsible engineer or team, whereas a design review is performed by someone other than the responsible engineer.

6.2.

Design standard The requirements contained within the BP Tubular Design Manual (BPA-D-003) shall be applied for both the tubing and casing programme basis of design. The basis of design will address parameters within which it is acceptable to plan further wells in a programme, campaign or area without further detailed design. When these parameters are exceeded, a detailed reassessment of the design is required. The BP Tubular Design Manual lists both default load cases and a sequence of alternate load cases to be considered should the default load case be judged either too onerous or not applicable. Inability to meet the default and alternate load cases renders a design unacceptable without a granted deviation. Every tubular component in the load path or forming a part of the pressure envelope shall be designed for the anticipated loads. This includes completion jewellery, crossovers, landing strings, risers, hangers and running tools. See also Clause 6.5 which requires a Well Category 3 review for any design outside the scope of the BP Tubular Design Manual BPA-D-003.

6.3.

Tools and design data Casing and tubing design shall be performed using the BP approved casing design software and methods as identified in the BP Tubular Design Manual. Exceptions shall be subject to EPT review. Some design procedures, such as the construction of a casing string to withstand non-uniform formation loading, require software other than the standard packages listed in the BP Tubular Design Manual. In such cases, EPT review is required. Every tubular component in the load path or forming part of the pressure envelope shall be traceable per API, ISO, and/or BP specifications and verified either by reference to the mill certificates or mechanical testing to have the expected mechanical performance. Every component shall also be in good condition, and all equipment should be suitable for expected service life. Casing and tubing design software are safety critical.

6.4.

Review Casing and tubing designs shall be subject to assurance review as a minimum as follows:

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GP 10-01 Casing and Tubing Design

Table 1 – Required Well Design Review Level Well Category 1. 2.

3.

All wells Wells with SITHP > 10,000 psi or SBHT > 300°F, or reservoir pressure > 15,000 psi, or H2S partial pressure > 0.05 psia, or water depth > 1000 ft (300 m) or using reduced drilling service or well control loads outside of the guidance of this ETP or the BP Tubular Design Manual Wells requiring material with specified yield strength > 125 ksi, or requiring sour service materials with specified yield strength  110 ksi, or having sealed or potentially sealed inaccessible annuli, or requiring modelling outside standard software capabilities, or using reduced production loads outside of the guidance of this ETP or the BP Tubular Design Manual

Minimum Review Level Within SPU SPU plus review by a party external to the SPU

SPU plus EPT review

Notes: 1. A party external to the SPU is a person of technical competence whose current performance contract is not directly dependent on the success of the SPU, and may include individuals from other SPUs, individuals from EPT or external consultants. 2. The final qualifier in Table 1 specifically targets complex completion designs (e.g. downhole flow control, multiple packers) that do not lend themselves to ready analysis in available tubular design software, but require either special handling with conventional tools or the use of modelling tools outside the purview of a nonspecialist.

6.5.

Design loads A minimum set of design loads, including setting depth, burst, collapse, tension and triaxial considerations for both the tube body and connection, is defined in the BP Tubular Design Manual. Designs governed by loads outside those listed in the BP Tubular Design Manual shall be subject to review as in Well Category 3 in Table 1. See also the explanatory comments in Clause 6.2.

6.6.

1.

All casing and liners shall be designed to withstand reasonably foreseeable well control burst loadings. The starting point for well control burst loading shall be gas to surface from casing shoe, or lower open hole fracture pressure. Casing designs using lesser well control loadings not appearing in the BP Tubular Design Manual as acceptable alternatives shall be subject to review as per Well Category 2 in Table 1.

2.

Casing designs shall include definition of the well control scenarios they accommodate and their rationale based on subsurface information, local experience and operational well control capabilities. Kick intensities for well design shall be based on appropriate and prudent application of pore pressure uncertainty as described in GP 10-15 Group Practice on Pore Pressure Prediction.

3.

All production casing and liners shall be designed for burst, to withstand the maximum pressure resulting from a tubing leak at the wellhead applied over the packer fluid.

Design factors The minimum acceptable design factors for BP tubular design calculations are given in Table 2.

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GP 10-01 Casing and Tubing Design

Table 2 – Minimum Casing and Tubing Design Factors Casing Tension Burst Collapse Triaxial Compression

7. 7.1.

Pipe 1.4 1.1 1.0 1.25 1.4

Connection 1.4 1.1 1.0 N/A 1.0

Tubing (Test) Pipe 1.1 1.1 1.1 1.1 1.1

Connection 1.1 1.1 1.1 N/A 1.0

Tubing (Service) Pipe 1.33 1.25 1.1 1.25 1.33

Connection 1.33 1.25 1.1 N/A 1.0

Procurement Standard Casing and tubing shall be manufactured, inspected and tested in accordance with the following standards: 

API Specification 5CT or ISO 11960 for casing and tubing;



API Specification 5L or ISO 3183 for line pipe used as casing or tubing;



GIS 10-001, GIS 10-002, GIS 10-004, GIS 10-006;



BP-EPT-IAS-02. The API and ISO standards listed together are identical, save their respective title pages.

7.1.1.

Conflicting standard requirements

Where requirements of procurement standards differ the more onerous requirement shall govern. 7.2.

Qualifying materials

7.2.1.

Sour and/or corrosive service

The materials selection process for wells expected to contain H 2S shall comply with NACE MR0175/ISO 15156. Only seamless grades of tubulars are acceptable for casing and tubing which may be exposed to H2S/sour environments as defined in NACE MR0175/ISO 15156. The materials selection process for production tubulars expected to contain CO 2 and/or H2S shall follow the requirements of BP EPT Guidance Note GN 036-13. In case of a conflict between this document and NACE MR0175 / ISO 15156, the more onerous requirement shall govern. 7.2.2.

Alteration of specification properties

Gross unintentional yielding of a tubular during application or installation renders that tubular out-of-specification and disqualifies that tubular from any barrier definition. Unintentional yielding excludes expandable tubulars. However, the declaration of an expandable tubular as a barrier should only follow a careful examination of the implications of that tubular on well integrity throughout the life of the wellbore, along with the qualification status of the expandable product. The term "application" includes well operation, intervention and stimulation. Field welding of tubulars is permitted on API Spec 5L/ISO 3183 grade line pipe and API Spec 5CT/ISO 11960 Grade K55 tubulars, and shall conform to the guidelines laid out in API RP 5C1/ISO 10405. Welding operations on other grades of pipe will require specific qualifications and procedures per GP 18-01. Page 12 of 14

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7.3.

GP 10-01 Casing and Tubing Design

Well-site inspection All casing, tubing and handling tubulars shall be visually inspected and drift tested as close to the point of use as practical to identify handling damage to the pipe body and threaded connections that could present problems during installation and/or over the life of the well.

8. 8.1.

Operation Loads Operations during installation and well life shall not exceed the loads under which exposed tubulars have been designed. A revised design evaluation shall be completed, should such an occurrence be contemplated. The term "well life" includes, but is not limited to, well servicing, routine integrity testing, well intervention, stimulation and through-tubing drilling.

8.2.

Setting depths Casing and liner setting depths shall be selected to provide a sufficient safety margin between formation fracture pressure and well control and/or casing cementing operations. Limitations on allowable well control operations shall be detailed in the design.

8.3.

Float equipment At least one downhole float valve shall be included on any casing string run through a hydrocarbon-bearing formation. Differential fill float equipment shall not be used on casing strings which are to be run through potential hydrocarbon-bearing zones. Auto fill float equipment shall be tripped prior to running through any hydrocarbon bearing zone.

9.

Abandonment Tubular considerations during abandonment are addressed in a separate document, Group Practice for Suspension, Abandonment and Zonal Isolation, GP 10-60.

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GP 10-01 Casing and Tubing Design

Bibliography [1]

ISO 13679, Petroleum and natural gas industries — Procedures for testing casing and tubing connections (see also equivalent document API RP 5C5)

[2]

API Recommended Practice 579, Fitness-For-Service

[3]

API Recommended Practice 90, Annular Casing Pressure Management for Offshore Wells

[4]

API Specification 5B, Threading, Gauging and Thread Inspection of Casing, Tubing, and Line Pipe Threads

[5]

API Specification 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections (see also equivalent document ISO 13679)

[6]

British Standard BS7910, BSI Guide on methods for assessing the accepting of flaws in fusion welded structures

[7]

NORSOK Standard D-010, Well integrity in drilling and well operations

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