1、Annular Casing Pressure Management for Offshore WellsAPI RECOMMENDED PRACTICE 90FIRST EDITION, AUGUST 2006REAFFIRMED, JANUARY 2012Annular Casing Pressure Management for Offshore WellsUpstream SegmentAPI RECOMMENDED PRACTICE 90FIRST EDITION, AUGUST 2006REAFFIRMED, JANUARY 2012SPECIAL NOTESAPI publica
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6、 publi-cation may conflict.API publications are published to facilitate the broad availability of proven, sound engineer-ing and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be
7、utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the a
8、pplicable requirements of that standard. API does not represent, warrant, or guarantee that such prod-ucts do in fact conform to the applicable API standard.All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical,
9、 photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 2006 American Petroleum InstituteFOREWORDThis recommended practice is under the jurisdiction of the API U
10、pstream Executive Com-mittee on Drilling and Production Operations (ECDPO) and was developed in cooperation with the Offshore Operators Committee (OOC). Additionally, The Minerals Management Service (MMS) provided general guidance and assistance in the development of this recom-mended practice.Nothi
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15、rom the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.Suggested revisions are invited and should be submitted to the Standards and Publications Department
16、 API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org.iiiCONTENTSPage1 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . . . . .11.2 Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.4 R
18、eferenced Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 SOURCE OF PRESSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.1 Thermally Induced Pressure . . . . . . . . . . . . . . . . . . . .
19、 . . . . . . . . . . . . . . . . . . . . .42.2 Operator-Imposed Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.3 Sustained Casing Pressure (SCP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.4 Monitoring . . . . . . . .
20、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52.5 Diagnostic Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 ANNULAR CASING PRESSURE MANAGEMENT PROGRAM . . . . . . . . . . . . . . .54 MAX
21、IMUM ALLOWABLE WELLHEAD OPERATING PRESSURE (MAWOP) .65 FIXED PLATFORM WELLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75.1 System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75.2 Methods a
22、nd Frequency of Monitoring Annular Casing Pressure . . . . . . . . . . . . .85.3 Detection of Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95.4 Annular Casing Pressure Evaluation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 .106 SUBSEA WELLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156.1 System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156.2 Design Considerations . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166.3 Methods and Frequency of Monitoring Annular Casing Pressure . . . . . . . . . . . .176.4 Detection of Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186.5 Annular Casing Pressur
25、e Evaluation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187 HYBRID WELLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217.1 System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、 . . . . . . . . . . .217.2 Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227.3 Methods and Frequency of Monitoring Annular Casing and Production Riser Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . .237.4 Detection of Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247.5 Annular Pressure Evaluation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .248 MUDLINE SUSPENSION WELLS. . . . . . . . . . . . . . .
28、 . . . . . . . . . . . . . . . . . . . . . . . .298.1 System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298.2 Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318.3 Monitori
29、ng, Pressure Detection, Annular Pressure Evaluation Testing and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329 DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329.1 Annular P
30、ressure Management Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329.2 Monitoring Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329.3 Diagnostic Test Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31、 . . . . . . . . . . . . . . .339.4 MAWOP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35vPage10 RISK ANALYSIS CONSIDERATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3610.1 Risk Assessment Techniques . .
32、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3610.2 Hazard Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3710.3 Consequence Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33、 . . . . .3710.4 Risk References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3811 APPENDIX AANNULAR PRESSURE MANAGEMENT FLOWCHARTS AND EXAMPLES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34、 . .3911.1 Fixed Platform Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3911.2 Subsea Well. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4811.3 Hybrid Well. . . . . . . . . . . . . . . . .
35、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5012 APPENDIX BEXAMPLE MAWOP CALCULATIONS . . . . . . . . . . . . . . . . . . . . .5912.1 Definition: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5912.2 Fixed Plat
36、form Wells: MAWOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6012.3 Subsea Wells: MAWOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6112.4 Hybrid Wells: MAWOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37、 . . . . . . . . .6112.5 Mudline Suspension Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6313 APPENDIX CWELLBORE SKETCHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6513.1 Fixed Platform Wells . . . . . . . . . . . . . . . . . . . .
38、 . . . . . . . . . . . . . . . . . . . . . . . . .6513.2 Subsea Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6613.3 Hybrid Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39、7113.4 Mudline Suspension Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7714 APPENDIX DPRESSURE CONTAINMENT AND LEAK PATH CONSIDERATIONS IN WELL DESIGN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8114.1 Casing and Cement. . . . . .
40、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81vi1Recommended Practice for Annular Casing Pressure Management for Offshore Wells1 General1.1 SCOPEThis Recommended Practice is intended to serve as a guide for managing annular casing pressure in offshore wells. Al
41、though the prevention of annular casing pressure is very important, it is beyond the scope of this document. Prevention of annular casing pressure is planned to be addressed in API RP 65, Part 2. The remediation of wells because of sustained casing pressure is also beyond the scope of this document
42、and is planned to be included in API RP 65, Part 3. This guide is meant to be used for offshore wells that exhibit annular casing pressure, including thermal casing pressure, sustained casing pressure (SCP) and operator-imposed pressure. This Recommended Practice covers monitoring, diagnostic testin
43、g, the establishment of a maximum allowable wellhead operat-ing pressure (MAWOP) and documentation of annular casing pressure for the various types of wells that occur offshore. Included also is a discussion of risk assessment methodologies that can be used for the evaluation of individual well situ
44、ations where the annular casing pressure is not within the MAWOP guidelines. This Recommended Practice recognizes that annular casing pressure results in various levels of risk to the safety of personnel, property and the environment. The level of risk presented by annular casing pressure depends on
45、 many factors, including the design of the well and the source of the annular casing pressure. This Recommended Practice provides guidelines in which a broad range of casing annuli that exhibit annular pressure can be managed in a routine fashion while maintaining an acceptable level of risk. Annula
46、r pressures that do not conform to the guidelines in this Recommended Practice may still have an acceptable level of risk, but they need to be evaluated on a case-by-case basis. This Recommended Practices establishes an acceptable level of risk for annular casing pressure using three parameters. Fir
47、st, annuli that exhibit annular casing pressure of 100 psig or less present little risk and should be monitored. Second, annular casing pressure that is greater than 100 psig and that has been diagnosed as sustained casing pressure (SCP) must bleed to zero psig. Third, a Maximum Allowable Wellhead O
48、perating Pressure (MAWOP) is established for each non-structural casing annulus that exhibits annular casing pressure, including thermal casing pressure, sustained casing pressure or operator-imposed pressure. If the annular casing pressure does not meet the criteria established in this Recommended
49、Practice, this does not mean that the risk pre-sented by the annular pressure is unacceptable. Rather, it indicates that the annular casing pressure needs to be managed on a case-by-case basis that goes beyond the scope of this Recommended Practice. The case-by-case management of annular casing pres-sure may include the use of risk assessment techniques. Techniques that may be used for case-by-case risk assessment are dis-cussed in Section 10 of this Recommended Practice. In some cases, the annular casing pressure may need to be reduced or eliminated by well work. In other cases, the
