1、 State of the Art Multiphase Flow Metering API PUBLICATION 2566 FIRST EDITION, MAY 2004 State of the Art Multiphase Flow Metering Measurement Coordination API PUBLICATION 2566 FIRST EDITION, MAY 2004 SPECIAL NOTES API publications necessarily address problems of a general nature. With respect to par
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13、API, Standards department, 1220 L Street, NW, Washington, DC 20005, standardsapi.org. API Project 2002-100094 API COPM WHITE PAPER STATE OF THE ART MULTIPHASE FLOW METERING This “White Paper” provides information on multiphase flow metering systems gleaned from more than 150 published documents that
14、 are in the public domain. The documentation was prepared from information obtained through mid-2002. No additional research has been funded in the development of this report. It should be noted that the indicated performances data stated in these published documents have not necessarily been verifi
15、ed by an independent body. The listing of these references in the Appendix 2 is intended to provide a comprehensive source of data and information on multiphase metering; the reader needs to carefully review the source of the data in the documents when utilizing the information. The “White Paper” wa
16、s commissioned by the American Petroleum Institute (API) Committee on Petroleum Measurement (COLM) to be used as a framework in the development of “Recommended Practices” on the application of multiphase flow meters in Upstream Production Operations. The format of this white paper follows substantia
17、lly the outline developed for this project by the Multiphase Metering Standards Task Group. The term “multiphase metering” in its broadest interpretation is referred to both the wet gas metering as well as the measurement of oil, water, and gas streams. Whether one is conducting a “wet gas” or “mult
18、iphase” measurement typically depends on which fluid, (oil or gas) is the primary production as well as the type of equipment used. At the time of gathering this information there were over 1000 installations worldwide that use the multiphase metering technology to achieve improved production measur
19、ements and well testing. These multiphase metering systems have utilized four major processes, as shown in Figure 7 of the report, to obtain singlephase flow rates from a multiphase flow stream. The four processes include the conditioning of flow stream, volumetric component measurements, component
20、velocity measurements, and modeling of the multiphase flow. These subjects are discussed in Sections 1-7 of the report. The objective of these sections is to provide the reader with a working knowledge of the principle techniques used in multiphase measurements. This background is used, in Section 8
21、, to propose a classification for multiphase metering systems. Sections 9 and 10 review methods used to specify and assess the performance of the multiphase meters. The developments in wet gas metering have come from two different directions. A large amount of effort has gone into developing “correc
22、tion factors” to improve the accuracy of single-phase gas metering devices that are used in conditions Final Report April 2004 2 v API Project 2002-100094 where a small amount of liquid is present. On the other hand, elements of the multiphase metering technology have been modified to develop wet ga
23、s metering systems. Sections 12-15 discuss types of wet gas, measurement techniques used in wet gas metering, and the performance of wet gas metering systems. Performance assessment and verification of multiphase and wet gas meters are complicated by the lack of commonly accepted protocol and standa
24、rds. Current approaches used by operators and industry projects to address these issues are discussed in Section 17. Guidelines to be used for installations, qualification testing, and field testing of multiphase and wet gas metering systems are discussed in Sections 18-21. The users of multiphase a
25、nd wet gas meters face three major technical challenges in addition to justifying the cost and risk of the deploying new technology. These challenges are: Selecting and qualifying multiphase meters for different applications. Assessing the performance of the multiphase meters after installation. Get
26、ting approval to use multiphase meters from appropriate regulatory bodies. There is currently no single document that users of multiphase metering systems can consult to address the above issues. Users have relied on vendor information for procurement of multiphase metering systems in a majority of
27、the current installations. There is concurrence within the industry that a “Standard” or “Recommended Practice” (RP) be created to establish a common language to describe the performance of these systems. There is also a need to develop a commonly accepted protocol and procedures to evaluate the per
28、formance of multiphase metering systems. Should API decide to pursue the development of a “Standard” or a “Recommended Practice” on multiphase flow meters, the information in this report, as well as a number of currently available specifications listed in Section 22, should provide helpful direction
29、 and technical resource for the development of the new document. Final Report April 2004 3 vi Table of Contents 1 INTRODUCTION 1 2 NOMENCLATURE AND TERMS USED IN MULTIPHASE FLOW 2 3 THE NEED FOR MULTIPHASE AND WET GAS METERS .2 4 MULTIPHASE METER AND WET GAS METER INSTALLATIONS .4 5 MULTIPHASE FLOW
30、REGIMES 6 6 PRINCIPLES OF MULTIPHASE MEASUREMENTS 8 7 MULTIPHASE MEASUREMENT TECHNIQUES 9 7.1 Volumetric Fraction Measurements Using Non-Nuclear Methods .10 7.2 Volumetric Fraction Measurements Using Gamma Ray Attenuation .11 7.3 Measurement of Component Velocities .13 8 CLASSIFICATION OF MULTIPHASE
31、 METERS .14 8.1 Type I Multiphase Measurement System 15 8.2 Type II Multiphase Measurement Systems 15 8.3 Type III Multiphase Measurement Systems 15 9 ACCURACY- UNCERTAINTY 16 9.1 Specifications for AccuracyUncertainty 18 10 PERFORMANCE OF COMMERCIAL MULTIPHASE METERS 21 11 WET GAS METERING .22 12 T
32、YPES OF WET GAS 23 12.1 Type I wet gas 24 12.2 Type II wet gas .25 12.3 Type III wet gas .25 13 WET GAS METERING STRATEGIES 25 14 METERING SYSTEMS FOR TYPE I WET GAS 26 15 METERING SYSTEMS FOR TYPE II WET GAS .27 16 METERING SYSTEMS FOR TYPE III WET GAS .29 17 PERFORMANCE- MULTIPHASE AND WET GAS MET
33、ERING SYSTEMS 29 18 INSTALLATIONS GUIDELINES 30 19 TESTING GUIDELINES .33 19.1 Items to have available for review before and during tests .33 19.2 Performance of FAT 34 19.3 Items to be made available to users at the end of FAT 35 20 FIELD TESTING GUIDELINES .36 21 PERIODIC FIELD TESTING 38 22 REGUL
34、ATIONS AND STANDARDS 39 APPENDIX 1 NOMENCLATURE, TERMS, AND DEFINITIONS 41 APPENDIX 2 REFERENCED PUBLICATIONS 44 APPENDIX 3 SURVEY FORMS, PERFORMANCE SPECIFICATIONS .54 vii API Project 2002-100094 API COPM WHITE PAPER STATE OF THE ART MULTIPHASE FLOW METERING 1- INTRODUCTION This report documents in
35、formation available in open literature, and from vendors, on the state of the art of multiphase metering systems. The term “multiphase metering” in its broadest interpretation can be used to refer to both wet gas metering, as well as, the measurement of oil, water, and gas portions of commingled str
36、eams, which is commonly referred to as “multiphase metering”. Whether one is conducting a “wet gas” or “multiphase” measurement typically depends on which fluid (oil or gas) is the primary production, as well as, the type of equipment used. This report documents both wet gas and multiphase metering
37、systems. There are many more multiphase metering installations than wet gas metering installations. Also, the amount of literature and practical field tests available for multiphase meters is much more extensive than for wet gas metering. This imbalance in available information and literature is ref
38、lected in the coverage of the two subjects in this report. The information in this report is intended to guide the American Petroleum Institute Committee on Petroleum Measurement, and other API Task Groups, in the development of “Recommended Practices” or “Standards” applied to the multiphase measur
39、ements of fluid streams in Upstream Production Operations. The format of this white paper follows substantially the format specified by the Multiphase Metering Standards Task Group in the scope of work for this project. There are currently over 1000 installations worldwide (IV-30)that utilize the ne
40、w multiphase measurement technology to conduct production measurements in oil and gas producing fields. The pace of these installations has accelerated significantly over the past 5 years (IV-30). During this period a large amount of data related to the performance of multiphase and wet gas metering
41、 devices have been published as listed in Appendix 2. Multiphase measurement is a maturing technology (II-3). Significant amount of field and performance data are available (II-4, II-6, II-11, II-12, IV-1) to be utilized into some form of guideline to direct the forthcoming demand for the applicatio
42、n of this technology. The operators in the North Sea, who were the early users of this technology, have undertaken a number of regulatory initiatives to develop such guidelines (XII-3, XII-8). The need for guidelines is also anticipated by the operations in the Gulf of Mexico (XII-1, XII-2, XII-4, X
43、II-7). This issue is discussed further in Section 22 of this report. The gathering of the information on multiphase flow measurement technology, which is the objective of this “White Paper”, would be a first step in development of API specifications or standards on multiphase meters. To assist the A
44、PI effort, the nomenclature, terms and Numbers in parenthesis designate references in Appendix 2. V-30 is reference 30 in Section V. Final Report April 2004 5 1 API Project 2002-100094 definitions used by other bodies attempting to develop multiphase metering specifications have been adopted and use
45、d throughout this report. 2- NOMENCLATURE AND TERMS USED IN MULTIPHASE FLOW A number of terms and definitions are employed in describing multiphase flow and measurements. The Norwegian Society For Oil and Gas Measurement (NFOGM) have catalogued these terms in their Handbook Of Multiphase Metering” i
46、n reference XII-3. As a contribution to further the use of common terminology, and acknowledgement to the NFOGM efforts, this report has adopted these terms rather than develop new definitions. These terms and nomenclature, described in Appendix 1, are taken from reference XII-3 and will be used in
47、this report to describe multiphase flow and measurement processes. 3- THE NEED FOR MULTIPHASE AND WET GAS METERS Multiphase meters are devices that measure oil, gas, and water flow rates of a well stream without separating these components into individual phases. The new multiphase metering techniqu
48、es were developed to replace the conventional two and three-phase gravity based test separators that have been making multiphase measurements in production operations. Well tests are conducted routinely to monitor the flow rates from wells and forecast production. The well test data are also used fo
49、r reservoir management, production diagnostics and optimization and in some cases even production measurement. To obtain accurate and consistent test results from conventional well testing systems, the equipment requires high maintenance, field personnel intervention, and time to perform tests. The interest in the new multiphase meters for well testing was stimulated by several factors: The cost and size of conventional two and three phase test separators, particularly offshore (II-23). The testing time, high maintenance and field personnel required to get accu
