Minimum Wellhead Requirements - Enform

1 Edition 2 Sanction Nov Date 2011 Minimum Wellhead Requirements AN INDUSTRY RECOMMENDED PRACTICE (IRP) FOR THE CANADIAN OIL AND GAS INDUSTRY VOLUME 5 COPYRIGHT/RIGHT TO REPRODUCE Copyright for this Industry Recommended Practice is held by Enform , 2012. All rights reserved. No part of this IRP may be reproduced, republished, redistributed, stored in a retrieval system, or transmitted unless the user references the copyright ownership of Enform . DISCLAIMER This IRP is a set of best practices and guidelines compiled by knowledgeable and experienced industry and government personnel. It is intended to provide the operator with advice regarding the specific topic. It was developed under the auspices of the Drilling and Completions Committee (DACC). The recommendations set out in this IRP are meant to allow flexibility and must be used in conjunction with competent technical judgment.

2 It remains the responsibility of the user of this IRP to judge its suitability for a particular application. If there is any inconsistency or conflict between any of the recommended practices contained in this IRP and the applicable legislative requirement, the legislative requirement shall prevail. Every effort has been made to ensure the accuracy and reliability of the data and recommendations contained in this IRP. However, DACC, its subcommittees, and individual contributors make no representation, warranty, or guarantee in connection with the publication of the contents of any IRP recommendation, and hereby disclaim liability or responsibility for loss or damage resulting from the use of this IRP, or for any violation of any legislative Requirements . AVAILABILITY This document, as well as future revisions and additions, is available from Enform Canada 5055 11 Street NE Calgary, AB T2E 8N4 Phone: Fax: Website: Enform | 5055 - 11 Street, Calgary, AB T2E8N4 | Correction Request form for: all Enform Safety Services published documentsEnform welcomes comments at any time on any of these documents.

3 Comments are considered on the basis of clarity, intent, accuracy, or omissions. All comments are passed on to the committee chair or held until the next scheduled review, as appropriate. If you have any comments or suggestions on how we can improve this IRP, please let us know by filling out this form. This form can be submited by email or fax. ContactContactTitleCompanyAddressCityPro vincePostal CodeCountryPhone No (no spaces)Fax No (no spaces)emailIf you belong to an Association, please select the appropriate Member AssociationCommentsSelect documentCorrection type:Correction/administrativeTechnicalB roken linkPage #, Section:Description of suggested change:Reasons/rationale for suggestion: IRP 05 November 2011 Page i Table of Contents Preface .. vii Scope and Forward .. vii Revision Process .. ix Sanction .. ix Acknowledgements .. x Copyright Permissions .. x Wellhead Components and 1 Background on Oil and Gas Wells.

4 1 Casing .. 4 Tubing .. 5 Instrument and Control Lines .. 6 Types of Wells .. 6 Component Requirements Applicable to All Wellheads .. 9 Manufacturing Requirements (API / ISO compliance)9 Salvaged Wellhead Component Requirements .. 10 Pressure Rating Requirements .. 10 Full Bore Access Requirements .. 11 Pressure Relief Access on Side Outlets .. 11 Basic Components of a Wellhead .. 11 Casing Head .. 12 Casing Spool .. 15 Casing Hangers .. 17 Packoff 19 Tubing Head .. 20 Tubing Hanger .. 24 Tubing Head Adaptor .. 28 Christmas Tree .. 30 Connections .. 34 Seals .. 46 Sweet Flowing Wells .. 50 Below 51 Above MPa .. 52 Low Pressure / Low Risk Gas Wells .. 53 Critical Sour, Sour and Corrosive Wells .. 55 Critical Sour Wells .. 55 Sour Wells .. 56 Corrosive Flowing Wells .. 58 Artificial Lift Wells .. 59 Page ii IRP 05 November 2011 Reciprocating Rod Pump.

5 60 Progressing Cavity Pump (PCP) .. 63 Plunger Lift .. 64 Electric Submersible 66 Hydraulic Pump .. 68 Gas Lift .. 68 Velocity String .. 69 Coiled Tubing .. 69 Other Well Types .. 70 Injection or Disposal .. 70 Thermal Operations .. 73 Cavern Storage Well .. 78 Observation Well .. 79 Other Strings (not part of well flow) .. 79 Environmentally Sensitive Areas .. 80 Cold Climate Considerations .. 80 Wellhead Implementation .. 81 General Responsibilities in Wellhead Implementation .. 81 Determining Wellhead Requirements .. 82 Required Information Gathering .. 82 Transmitting required data for Wellhead design .. 85 Competency Requirements for Wellhead design .. 85 Wellhead Installation .. 85 Contractor Competency and 85 Pre-Spud Meeting .. 86 Installation Personnel .. 86 Installation Procedures .. 87 Pressure Testing Connections and Seals.

6 90 Installation Considerations .. 91 Post-Installation Requirements .. 92 Wellhead Protection .. 92 Wellhead Intervention .. 93 On-Site Audit .. 93 Intervention Plan .. 93 Contractor Competency and 93 Pre-Intervention Meeting .. 94 Dismantling Procedures .. 94 Make-up Procedures .. 95 Shallow Gas Well Intervention Requirements .. 96 Post-Intervention Requirements .. 96 Monitoring and Maintenance .. 96 Documented Maintenance Schedule and Procedure 96 Wellhead Pressure Testing .. 96 Rod Pumping Well Maintenance .. 97 Pressure Shut Down System Maintenance .. 97 Procedure for Closing Gate Valves .. 99 IRP 05 November 2011 Page iii Weld Repair of Threaded Components .. 99 Wellhead Requirements for Suspended Wells .. 99 Appendix A - Flange/Ring dimensions.. 101 Appendix B - Trim Selection Chart .. 105 Appendix C: API 6A Table 2 - Temperature Ratings.

7 107 Appendix D: Table 1 from ERCB Directive 013: Suspension Requirements for Wells .. 109 Acronyms .. 113 References .. 114 Page iv IRP 05 November 2011 List of Figures Fig ure 1. Simplified Diagram of Casing and Tubing .. 2 Fig ure 2. Wellhead Basics .. 3 Fig ure 3. Well Types* .. 7 Fig ure 4. Casing Heads .. 13 Fig ure 5. Casing Spool .. 16 Fig ure 6. Casing Hangers .. 18 Fig ure 7. Packoff Flanges .. 19 Fig ure 8. Tubing 21 Fig ure 9. Tubing Head Threaded by Threaded or Welded .. 22 Fig ure 10. Tubing Head Flanged by Threaded or Welded .. 23 Fig ure 11. Tubing Hangers .. 25 Fig ure 12. Extended Neck Tubing Hanger .. 27 Fig ure 13. Back Pressure Valves .. 28 Fig ure 14. Tubing Head Adaptors .. 29 Fig ure 15. Christmas Tree for Flowing Well .. 30 Fig ure 16. Christmas Tree on Rod Pumping Well .. 31 Fig ure 17. Christmas Tree on Dual Completion Well .. 32 Fig ure 18. Example of Slip-On Weld (Cross Section).

8 36 Fig ure 19. Example of Butt Weld (Cross Section) .. 36 Fig ure 20. Example of Valve Removal Threading on Side Outlet .. 39 Fig ure 21. Clamp Hub .. 41 Fig ure 22. Sliplock Casing Head Examples .. 43 Fig ure 23. Roll-On Coiled Tubing Connection .. 45 Fig ure 24. API Metal Ring Gasket Styles .. 48 Fig ure 25. Wellheads for Sweet Flowing Well ( MPa) .. 51 Fig ure 26. Wellhead for High Pressure Sweet Flowing Well .. 52 Fig ure 27. Simplified Wellhead for Low Pressure / Low Risk Gas Wells .. 54 Fig ure 28. Non-Critical Sour Well Example .. 57 Fig ure 29. Integrated Pollution Control Stuffing Box and BOP .. 61 Fig ure 30. Wellhead for PCP Pump .. 63 Fig ure 31. Plunger Lift System .. 65Fi g ure 32. Wellhead for Electric Submersible Pump (ESP) .. 67 Fig ure 33. Coiled Tubing Hangers .. 70 Fig ure 34. Basic Injection Wellhead .. 71 Fig ure 35. Integral Flow-Tee BOP .. 74 Fig ure 36.

9 Simple Steam Injection Wellhead for SAGD .. 75 Fig ure 37. Additional Example of SAGD Wellhead for Rod Pumping .. 76 Fig ure 38. Example of Cyclic Steam (CSS) Wellhead .. 77 Fig ure 39. Cavern Storage Wellhead .. 78 IRP 05 November 2011 Page v List of Tables Revision History .. ix Range of Obligation .. x Table 1: Injection Material .. 72 Minimum Wellhead Requirements IRP 05 November 2011 Page vii PREFACE SCOPE AND FORWARD The IRPs for Minimum Wellhead Requirements have been crafted with one prime goal in mind to ensure safe and successful control and containment of fluids and pressure from drilling to abandonment. This is only possible when Wellhead design, installation, operation, and maintenance fit the actual well conditions over the entire life cycle of a well. ISO/FDIS 10423 defines a Wellhead as all the permanent equipment between the uppermost portion of the surface casing and the tubing head adaptor connection.

10 This IRP, however, will adopt a wider, more generic definition that also includes components attached to the Wellhead to meet well control Requirements . Hence all components and related equipment from the top of the outermost casing string up to but excluding the flowline valve will be considered part of the " Wellhead " in this IRP. This IRP will also, at times, consider components managed through the Wellhead to the extent they impact Wellhead design and operation. The ultimate function of a Wellhead is to contain and control the flow of liquids, gases and solids during the drilling, completion, workover, and ongoing operation of the well. A Wellhead needs to provide: A securely sealed surface termination for the various well casing strings. Necessary access to annular spaces. A means of suspending or installing production tubing and other subsurface equipment required to operate the well.