Coiled Tubing Well Control Equipment Systems

API RECOMMENDED PRACTICE 16ST SECOND EDITION, FEBRUARY 2021

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users of this recommended practice should not rely exclusively on the information contained in this document. Sound

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Copyright © 2021 American Petroleum Institute

ii

Foreword

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iii

Contents

Page

1. Scope 1

   1. General 1

   2. Operations Not Covered in this Document 1

2. Normative References 1

3. Terms, Definitions, Abbreviations, and Acronyms 2

   1. Terms and Definitions 2

   2. Abbreviations and Acronyms 13

4. Well Control Equipment 13

   1. General 13

   2. Coiled Tubing Operations 14

   3. Well Control Components 18

   4. Additional Well Control Components 27

   5. Well Control Equipment for Hydrogen Sulfide Service 29

5. Coiled Tubing Workstring and Connectors 29

   1. Coiled Tubing Workstring 29

   2. Coiled Tubing String Selection 30

   3. Axial Tensile Forces Applied to Coiled Tubing Workstrings 31

   4. Axial Compressive Forces Applied to Coiled Tubing Workstrings 32

   5. Coiled Tubing Collapse 33

   6. Bend Cycle Fatigue 33

   7. Coiled Tubing String Management 34

6. Downhole Flow Check Assembly 34

   1. General 34

   2. Coiled Tubing Bottomhole Assembly Connectors 34

   3. Downhole Flow Check Devices 35

7. Elastomers and Seals 36

   1. General 36

   2. Rapid Gas Decompression 37

   3. Chemical Compatibility 37

   4. Temperature Performance Range 38

   5. Extrusion Resistance 38

   6. Abrasion/Erosion Resistance 38

   7. Pressure Rating 38

   8. Other Considerations 38

8. Choke Manifolds and Choke Lines 40

   1. Purpose 40

   2. Choke Line Installation 40

   3. Choke Manifold Installation 40

9. Kill Lines 41

   1. Purpose 41

   2. Kill Line Installation 41

   3. Bleed-off Lines 42

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      Contents

      Page

10. Pump Lines 42

    1. Purpose 42

    2. Pump Line(s) Installation 42

    3. Conventional Circulation Through Coiled Tubing Reel Swivel and Piping 42

    4. Bleed-off Lines 43

11. General Description of Coiled Tubing Surface Equipment 44

    1. General 44

    2. Typical Coiled Tubing Unit Components 44

    3. Injector 44

    4. Tubing Guide Arch 46

    5. Coiled Tubing Reel 46

    6. Power Supply/Prime Mover 47

    7. Monitoring Equipment 47

    8. Control System 48

    9. Hoses and Hose Reel(s) 48

12. Well Control Equipment Testing 49

    1. General 49

    2. Performance Testing—Slip Ram, Pipe-Slip Ram, Shear Ram and Shear-Blind Ram 49

    3. Performance Load Test—Flow Check Assembly Connector 50

    4. Pressure Testing 50

    5. Test Documentation 52

    6. General Testing Considerations 53

    7. Pressure Test Devices 53

13. Well Control Equipment Operating System 53

    1. General 53

    2. Functional Requirements 54

    3. Well Control Equipment Operating System Components 55

    4. Reservoir 55

    5. Pump System and Pump Sizing 56

    6. Accumulator Bank and Accumulator Sizing 56

    7. Stripper Assembly Operating System 58

    8. Control Panel, Manifold and Hoses 58

    9. Hydraulic Control Fluid 59

    10. Accumulator Circuit Alarm Systems 59

14. Pre-job Planning and Preparation 60

    1. General 60

    2. Well Control Contingencies 60

    3. Job Planning 60

    4. Location—Equipment Layout 61

    5. Personnel Requirements 62

    6. Job Review 63

    7. Equipment Rig-up Considerations 63

    8. Coiled Tubing Service Considerations 64

Annex A (Informative) Coiled Tubing Well Control Stack Arrangements for Designated Pressure Categories 65

Annex B (Informative) Coiled Tubing Well Control Choke Manifold and Choke Line Configurations 78

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Contents

Page

Annex C (informative) Coiled Tubing Well Control Kill Line and Pump Line Configurations 87

Annex D (normative) Coiled Tubing Well Control Stack Mechanical Ram Performance Tests—Slip Ram and Pipe-slip Ram 88

Annex E (normative) Coiled Tubing Well Control Stack Mechanical Ram Performance Tests—Shear Ram and Shear- blind Ram 95

Annex F (informative) Coiled Tubing “Well-hopping” Well Control Stack Pressure Testing 98

Annex G (informative) Accumulator Sizing Calculations 100

Annex H (informative) Example Coiled Tubing Well Control Accumulator System Drawdown Test Form 106

Annex I (informative) Coiled Tubing Well Control Contingencies and Drills 108

Bibliography 119

Figures

1. Blind Ram 20

2. Pipe Ram 21

3. Shear Ram 22

4. Slip Ram 23

5. Shear-blind Combination Ram 24

6. Pipe-slip Combination Ram 25

1. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Quad-Ram

   Assembly, Single Pipe Ram + Dedicated SBR 66

2. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Quad-Ram

   Assembly, Dual Combi-Ram Assembly with Dedicated SBR 67

3. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Triple-Ram

   Assembly, Single Pipe Ram + Dedicated SBR 68

4. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Triple-Ram

   Assembly, Dual Combi-Ram Assembly with Dedicated SBR 69

5. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Dual

   Combi-Ram Assembly, Single Pipe Ram + Dedicated SBR 70

6. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-1, PC-2, PC-3) Dual

   Combi-Ram Assembly, Dual Combi-Ram with Dedicated SBR 71

7. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Quad-Ram Assembly,

   Single Pipe Ram + Dedicated SBR 72

8. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Quad-Ram Assembly,

   Dual Combi-Ram Assembly with Dedicated SBR 73

9. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Triple-Ram Assembly,

   Single Pipe Ram + Dedicated SBR 74

10. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Triple-Ram Assembly,

    Dual Combi-Ram Assembly with Dedicated SBR 75

11. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Dual Combi-Ram

    Assembly, Single Pipe Ram + Dedicated SBR 76

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    Contents

12. Recommended Coil Tubing Well Control Stack Equipment Configuration (PC-4) Dual Combi-Ram

Page

Assembly, Dual Combi with Dedicated SBR 77

1. Single Inline Choke Installation (PC-1 and PC-2)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 78

2. Single Inline Choke Installation (PC-3)—for Returns Taken through the Flow Cross or Flow Tee Installed

   in the Well Control Stack 79

3. Single Inline Choke Installation (PC-4)—for Returns Taken through the Flow Cross or Flow Tee Installed

   in the Well Control Stack 80

4. Dual Choke Manifold Installation (PC-1 and PC-2)—for Returns Taken through theFlow Cross or Flow Tee Installed in the Well Control Stack 81

5. Dual Choke Manifold Installation (PC-3)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 82

6. Dual Choke Manifold Installation (PC-4)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 83

7. Dual Choke Manifold Installation (PC-1 and PC-2)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 84

8. Dual Choke Manifold Installation (PC-3)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 85

9. Dual Choke Manifold Installation (PC-4)—for Returns Taken through the Flow Cross or Flow Tee Installed in the Well Control Stack 86

C.1 Kill Line and Pump Line Installation (All PC Conditions) 87

1. Primary Well Control Stack Drawdown Test Form—Stack Configuration A 106

2. Dedicated Shear-blind Ram Accumulator Drawdown Test Form 107

Tables

1. Pressure Categories for CT Well Control Equipment 15

2. CT Well Control Stack Equipment Configuration 16

3. Example Collapse Width Predictions and Minimum Stack Bore Size for CT 33

1. Personnel Actions to Address a Stripper Assembly Leak 108

2. Personnel Actions to Address a CT Workstring Leak Between the Tubing Guide Arch and Service Reel 109

3. Personnel Actions to Address a CT Workstring Leak between the Tubing Guide Arch and Stripper Assembly 111

4. Personnel Actions to Address a CT Workstring Separation Failure between the Tubing Guide Arch and Service Reel 113

5. Personnel Actions to Address a Tensile Separation Failure of the CT Workstring between the Stripper

   Assembly and Injector 114

   I.6 Table ........................................................................................................................................................

   1. 6—Personnel Actions to Address a Compressive CT Workstring Buckling Failure between the Injector

and Stripper 116

1. Personnel Actions to Address a Leak between the Surface Tree Connection and the Lowest Pressure- sealing Well Control Stack Ram Component 117

2. Personnel Actions to Address a Leak in the Well Control Stack between the Stripper Assembly and Pipe Ram Component 118

viii

Introduction

This standard represents a composite of the practices employed by various operating and service vendor companies in well intervention operations. This recommended practice is under the jurisdiction of the API Committee on Standardization of Oilfield Equipment and Materials.

The objective of this recommended practice is to assist the oil and gas industry in promoting personnel safety, public safety, integrity of well control equipment and preservation of the environment for land and marine well intervention operations. This recommended practice is published to facilitate the broad availability of proven, sound engineering and operating practices that meet the stated objective through practices that improve reliability and reduce risk to acceptable levels.

This Recommended Practice is provided to meet the need for assembly and operation of coiled tubing well control equipment and systems. Coiled tubing well control practices typically rely on mechanical barriers as the primary means for well control. This recommended practice does not present all of the operating practices that can be employed to successfully install and operate well control equipment systems in coiled tubing well intervention services. Practices set forth herein are considered acceptable for accomplishing the job as described: however, equivalent alternative installations and practices can be used to accomplish the same objectives. Individuals and organizations using this standard are cautioned that operations must comply with requirements of federal, state or local regulations. These requirements should be reviewed to determine whether violations can occur.

Coiled tubing well intervention services are being conducted with full regard for personnel safety, public safety and preservation of the environment in such diverse conditions as metropolitan sites, wilderness areas, ocean platforms, deepwater sites, barren deserts, wildlife refuges and arctic ice packs. The information presented in this recommended practice is based on this extensive and wide-ranging industry experience.

ix

Coiled Tubing Well Control Equipment Systems

1. Scope

   
   

   1. General

      
      

      This Recommended Practice (RP) addresses coiled tubing well control equipment assembly and operation as it relates to well control practices. Industry practices for performing well control operations using fluids for hydrostatic pressure balance are not addressed in this RP.

      
      

      This document covers well control equipment assembly and operations used in coiled tubing intervention and coiled tubing drilling/milling applications performed through:

      
      

      — tree equipment constructed in accordance with API 6A or API 11IW or both,

      
      

      — a surface flow head or surface test tree constructed in accordance with API 6A,

      
      

      • a fracture stimulation wellhead assembly (with at least two gate valves installed for isolation),

        
        

      • drill pipe or workstrings with connections manufactured in accordance with API 5CT, API 5DP or API 7-1, or a combination thereof.

      
      

   2. Operations Not Covered in this Document

      
      

      The following operations are not covered in the scope of this document:

      
      

      1. coiled tubing well intervention operations without the tree equipment (or surface test tree) in place;

         
         

      2. coiled tubing drilling operations without the tree equipment (or surface test tree) in place;

         
         

         2

      3. coiled tubing less than 1/ in. outside diameter (OD) used in well intervention operations;

      
      

      d) coiled tubing intervention operations within pipelines and flowlines;

      
      

      e) open-water coiled tubing intervention operations;

      
      

      f) reverse circulation of solids-laden fluids or gas through the coiled tubing workstring.

      
      

2. Normative References

The following referenced documents are indispensable in the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda) applies.

API Specification 5ST, Specification for Coiled Tubing

API Specification 6A, Specification for Wellhead and Tree Equipment

API Technical Report 6AF1, Technical Report on Temperature Derating of API Flanges under Combination of Loading

API Specification 7NRV, Specification for Drill String Non-Return Valves (1st Edition July, 2006)

API Specification 7K, Specification for Drilling and Well Servicing Equipment

1