Recommended Practice for Subsea Capping Stacks

API RECOMMENDED PRACTICE 17W FIRST EDITION, JULY 2014

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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. Abbreviations 4

4. System Requirements 4

   1. General 4

   2. Subsea Capping Stack Categories 5

   3. Interface Descriptions 6

   4. System Design and Functional Requirements 8

   5. Manufacturing 24

5. Use of a Subsea Capping Stack 28

   1. Initial Actions 28

   2. Equipment Notification and Callout 28

   3. Well Condition Assessment 29

   4. Deploying the Subsea Capping Stack 32

   5. Operating Parameters 35

   6. Operating Personnel 37

   7. Logistics and Deployment Plans 38

6. Preservation, Maintenance, and Testing 39

   1. Testing 39

   2. Maintenance 46

   3. Inspections 50

   4. Preservation 51

   5. Testing, Maintenance, Inspection, and Preservation Personnel 56

Annex A (informative) Subsea Well Capping Contingency Procedures 58

Annex B (informative) Example Procedures 61

Bibliography 65

Figures

1. Category 1 (Cap) 5

2. Category 2 (Cap and Flow) 6

3. Example of Three Likely Subsea Capping Stack Attachment Points 30

Tables

1. Example of Pre-deployment Interface Testing Matrix 33

2. Example Routine Testing Schedule 40

3. Example Non-routine Testing Schedule 40

4. Example ROV Interface Testing 42

5. Example Periodic Maintenance Schedule 46

6. Subsea Capping Stack Field Performance Report Example 48

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 and can be used to improve existing 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 presents recommendations for neither procedures nor equipment for containment systems that may be connected to a subsea 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 and recovery 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.

The following referenced documents are useful 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 amendments) applies.

API Specification 6A, Specification for Wellhead and Christmas Tree Equipment

API Specification 6AV1, Specification for Validation of Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore 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 Systems

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 Recommended Practice 17G, Recommended Practice for Completion/Workover Risers

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