Recommended Practice for the Design, Testing, and Operation of Subsea Multiphase Flow Meters

API RECOMMENDED PRACTICE 17S FIRST EDITION, JUNE 2015

Special Notes

API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.

Neither API nor any of API’s employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of API’s employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.

Users of this standard assume all responsibility for ensuring safe handling and compliance with all applicable laws regarding radioactive materials.

API publications are published to facilitate the broad availability of proven, sound engineering 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 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 applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.

Classified areas may vary depending on the location, conditions, equipment, and substances involved in any given situation. Users of this Recommended Practice should consult with the appropriate authorities having jurisdiction.

Users of this standard assume all responsibility for ensuring safe handling and compliance with all applicable laws regarding radioactive materials.

All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, NW, Washington, DC 20005.

Copyright © 2015 American Petroleum Institute

Foreword

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.

Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.

Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standards@api.org.

iii

Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, Acronyms, and Abbreviations 1

   1. Terms and Definitions 1

   2. Acronyms and Abbreviations 4

4. Multiphase Flow Meter (MPFM) Applications 4

   1. General Uses 4

   2. MPFM Locations 5

5. Design Criteria 6

   1. Functional Specification 6

   2. Governing Specification 6

   3. Standard Meter Design Parameters. 6

   4. Meter Sizing 7

   5. Performance 7

   6. Mechanical Design 9

   7. Thermal Management and Insulation 10

   8. Subsea Architecture Interface 10

   9. Electrical Connectivity 11

   10. Electrical Enclosure and Printed Circuit Board (PCB) 13

   11. Labeling and Marking 13

   12. Additional Equipment 14

6. Radiation Based Devices 15

   1. General 15

   2. Transportation and Importation 15

   3. Repair 15

   4. Decommissioning 15

7. Reliability 15

   1. General 15

   2. Redundancy 17

   3. Retrievability 18

8. Test Requirements and Recommendations 19

   1. General 19

   2. Design Validation 19

   3. Qualification Testing 21

   4. Factory Acceptance Testing 22

   5. Performance Tests 24

   6. Integration and Installation Assurance 25

9. Commissioning 27

   1. General 27

   2. Meter Commissioning and Configuration 27

      v

      Contents

      Page

10. Operations and Maintenance 30

    1. In Situ Checks 30

    2. Configuration Parameters Audit Trail 31

    3. Maintenance 31

Bibliography 32

Figures

1. Reliability Plan Overview 17

2. Typical Flow Chart for Integration and Installation Assurance Plan 28

Table

1 Considerations for Meter Performance Strategy 8

vi

Introduction

Multiphase flow is a complex fluid phenomenon presenting many observable and distinctly different spatial patterns. These flow regimes are a function of fluid composition, velocity, flow orientation, geometry and operating conditions. This characteristic of multiphase flow creates a greater number of variables requiring measurement than seen in single phase flow. Multiphase flow meters (MPFMs) tend to use a combination of measurement principles and software models to delineate component parameters of the specific flow condition undergoing measurement. These elements are further combined to simultaneously resolve the total flow state and inform the user of the flow rate of each phase.

This document is intended for use by persons familiar with the principles of multiphase flow and the technologies used to measure its constituent parts. It is the intent of this Recommended Practice (RP) to outline a strategy for the correct sizing, specification, integration, and testing of MPFMs to maximize their performance for a specific application. Measurement techniques used in MPFMs are every bit as complex as the flow itself and only brief descriptions are included herein. It is recommended that the reader be acquainted with API MPMS Ch. 20.3 which describes in detail the technologies of multiphase metering, calibration, measurement uncertainty, and operation. API MPMS Ch. 20.3 referred to in various parts of this document wherein the reader should seek further information or best practice. API MPMS Ch. 20.3 is not specific to subsea applications and some topside measurement methods are included.

Various expertise is required throughout the life cycle of the MPFM to achieve optimal performance. Due to the number of interfaces and design parameters an appropriate strategy is required to ensure the meter is appropriate for its specific application. This RP acts as a guide for the responsible engineer outlining key parameters of the plan that quantifies meter performance based on application, sizing data, technology constraints, and performance checks through supplier, independent facilities, and in situ tests.

There is a distinct separation in ownership between MPFM specification, testing, and installation versus commissioning and operation. This RP addresses equipment design in Section 4 to Section 8 and commissioning/ operational issues in Section 9 and Section 10. To ensure accuracy and functionality of the MPFM, there should be a coherent handover between equipment design and long term operation. A number of operational issues are addressed in this RP, as well as metering methodologies, but these are only intended as suggested interfaces that should be addressed by the responsible engineer. This RP should be used in combination with appropriate measurement and operational standards to develop a comprehensive strategy for the design, installation, and long term operation of an MPFM.

vii

Recommended Practice for the Design, Testing, and Operation of Subsea Multiphase Flow Meters

1. Scope

   This document provides recommendations for the sizing, specification, system integration, and testing of subsea flow meters [henceforth referred to as multiphase flow meters (MPFMs)] for measurement of full stream, multiphase flow. This Recommended Practice (RP) includes wet gas flow meters as a subset of MPFMs. In-line MPFMs are typically used in subsea applications and are the focus of this RP.

   
   

   These recommendations and guidelines are intended for use by the engineer responsible for the delivery of the MPFM. Due to the nature of multiphase flow measurement it is anticipated that a cross-disciplinary team may be involved throughout its deployment and operational life.

   
   

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 Manual of Petroleum Measurement Standards (MPMS), Chapter 20.3, Measurement of Multiphase Flow

   
   

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

   
   

   API Specification 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment

   
   

   API Standard 17F, Standard for Subsea Production Control Systems

   
   

   API Recommended Practice 17N, Recommended Practice for Subsea Production System Reliability and Technical Risk Management

   
   

3. Terms, Definitions, Acronyms, and Abbreviations

3.1 Terms and Definitions

For the purpose of this document the following terms and definitions apply. For consistency, these are identical to those used in API MPMS Ch. 20.3.

3.1.1

accuracy

The degree of conformity of a measurement to a known standard for the unit of measurement.

3.1.2

actual conditions measurement conditions line conditions

flowing conditions

Conditions of pressure and temperature of the fluid at the point where fluid properties or flows are measured.

1