Recommended Practice for Subsea Capping Stacks

API RECOMMENDED PRACTICE 17W SECOND EDITION, MARCH 2021

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Foreword

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Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 2

   1. Terms and Definitions 2

   2. Acronyms, Abbreviations, Symbols, and Units 3

4. System Requirements 4

   1. General 4

   2. Subsea Capping Stack Categories 4

   3. Interface Descriptions 6

   4. System Design and Functional Requirements 8

   5. Manufacturing 22

5. Subsea Capping Stack Operations 25

   1. General 25

   2. Initial Actions 25

   3. Equipment Notification and Callout 25

   4. Well Condition Assessment 26

   5. Deploying the Subsea Capping Stack 29

   6. Operating Parameters 33

   7. Operating Personnel 35

   8. Logistics and Deployment Plans 35

6. Storage, Preservation, Maintenance, and Testing 37

   1. General 37

   2. Testing 37

   3. Maintenance 43

   4. Inspections 46

   5. Preservation 48

   6. Testing, Maintenance, Inspection, and Preservation Personnel 52

Annex A (informative) Subsea Well Capping Contingency Procedures 54

Annex B (informative) Example Procedures 57

Bibliography 61

Figures

1. Category 1 (Cap) 5

2. Category 2 (Cap and Flow) 6

3. Example of Three Likely Subsea Capping Stack Attachment Points 28

Contents

Tables

Page

1. Example of Pre-deployment Interface Testing Matrix 31

2. Example Routine Testing Schedule 38

3. Example Non-routine Testing Schedule 38

1. Example Periodic Maintenance Schedule 43

2. Subsea Capping Stack Field Performance Report Example 45

Recommended Practice for Subsea Capping Stacks

1. Scope

   
   

   This document provides subsea capping stack recommended practices for design, manufacture, and use. The document applies to the construction of new subsea capping stacks. The document can aid in generating a basis of design (BOD) document, as well as preservation, transportation, maintenance, testing documents, and operating instructions.

   
   

   This document does not address procedures and equipment downstream of the capping stack. All equipment and operations downstream of the subsea capping stack are considered part of a containment system and are not within the scope of this recommended practice.

   
   

   Annex A contains a discussion of possible subsea capping contingency procedures. Annex B contains example procedures for deployment, well shut-in, recovery, and storage of a subsea capping stack.

   
   

2. Normative References

The following referenced documents are indispensable for 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 amendments) applies.

API Specification 6A, Specification for Wellhead and Tree Equipment

API Standard 6AV1, Validation of Safety and Shutdown Valves for Sandy Service

API Specification 7-1, Specification for Rotary Drill Stem Elements

API Specification 7-2, Specification for Threading and Gauging of Rotary Shouldered Thread Connections

API Specification 14A, Specification for Subsurface Safety Valve Equipment, 11th Edition, October 2005, Reaffirmed 2012

API Specification 16A, Specification for Drill-Through Equipment

API Specification 16C, Choke and Kill Equipment

API Specification 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment

API Recommended Practice 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations

API Specification 17D, Design and Operation of Subsea Production Equipment, 2nd Edition, May 2011

API Standard 17G, Design and Manufacture of Subsea Well Intervention Equipment

API Recommended Practice 17H, Remotely Operated Tools and Interfaces on Subsea Production Systems

API Standard 53, Well Control Equipment Systems for Drilling Wells

API Specification Q1, Specification for Quality Management System Requirements for Manufacturing Organizations for the Petroleum and Natural Gas Industry