Managed Pressure Drilling Operations

— Pressurized Mud Cap Drilling with a Subsea Blowout Preventer

API RECOMMENDED PRACTICE 92P FIRST EDITION, JUNE 2019

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.

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 used. 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.

Users of this document should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.

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, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001-5571.

Copyright © 2019 American Petroleum Institute

ii

Foreword

The verbal forms used to express the provisions in this specification are as follows.

• the term “shall” denotes a minimum requirement to conform to the specification;

  
  

• the term “should” denotes a recommendation or that which is advised but not required to conform to the specification;

  
  

• the term “may” denotes a course of action permissible within the limits of a standard;

  
  

• the term “can” is used to express possibility or capability.

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.

ThisdocumentwasproducedunderAPIstandardizationproceduresthatensureappropriatenotificationandparticipation 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, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. 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, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.

Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.

Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 1

   1. Terms and Definitions 1

   2. Abbreviations 3

4. Managed Pressure Drilling Overview 4

   1. Managed Pressure Drilling Objectives 4

   2. Available Managed Pressure Drilling Solutions 4

   3. Mud Cap Drilling Methods 5

5. Logistics 7

6. Equipment 7

   1. Surface Equipment 7

   2. Marine Equipment 8

   3. Control Systems 22

7. Drill String 23

   1. General 23

   2. General Requirements—Drill Pipe 23

   3. General Requirements for the Bottom-hole Assembly 23

   4. Drill String Design 24

8. Drilling Fluid Considerations 24

   1. Hydraulics 24

   2. Light Annular Mud 25

   3. Sacrificial Fluid 26

9. Well Control and Well Integrity 27

   1. General 27

   2. Introduction 27

   3. Well Barrier Elements 27

   4. Pressurized Mud Cap Drilling Operations Matrix 29

   5. Contingency Plans 30

   6. Well Control Action Drills 31

   7. Drilling Fluid 32

   8. Use of the BOP/LMRP during Pressurized Mud Cap Drilling Operations 32

   9. Roles and Responsibilities 32

10. Managed Pressure Drilling Operational Guidelines 32

    1. General 32

    2. Training 32

    3. Wellsite Supervision 33

    4. Metocean and Environmental Considerations 33

    5. Engineering and Design 35

Annex A (informative) PMCD Illustrations 53

Contents

Page

Bibliography 56

Figures

1. Pressure Increases with Depth Based on the Density of the Fluid Contained 6

2. Example Equipment Schematic for PMCD with a Subsea BOP 7

3. Example of Bleed-off System 8

4. Example MPD ATR Riser Component Configuration 13

5. Example MPD BTR Riser Components Configuration 15

6. Example of Buckling Load Analysis Showing Interrelationship between Mud Weight and Tension Setting ... 18

7. Well Barrier Schematic Example 29

8. Example DP Watch Circles 34

9. Example DP Drift-off Curve 35

10. Transition from PMCD to Conventional or SBP Drilling 38

11. Surface Casing Pressure during PMCD 39

1. PMCD with LAM on the Annular and Seawater inside the String 53

2. PMCD with LAM and Mixed Interface on the Annular 54

3. PMCD with Combination of Sacrificial and Formation Fluid above the Fracture 55

Tables

1. Example PMCD Operations Matrix 30

2. Well Control Incident Scenarios 31

3. Example Well Control Drills 31

4. Injectivity Test Decision Matrix 36

5. Cause and Effect Matrix 41

6. Operations Matrix 42

Introduction

These guidelines (recommended practices)—prepared by the IADC Underbalanced Operations (UBO) and Managed Pressure Drilling Committee, and consisting of representatives from various IADC member companies—represent a composite of the practices employed by various operating companies, service companies, and drilling contractors in managed pressure drilling operations. In some cases, a reconciled composite of the various practices employed by these companies was used. This publication is under the jurisdiction of the American Petroleum Institute, Drilling and Production Operations Subcommittee.

Managed pressure drilling operations are being conducted with full regard for personnel safety, public safety, and preservation of the environment in such diverse conditions as urban sites, wilderness areas, ocean platforms, deep- water sites, very hot barren deserts, and cold-weather areas, including the Arctic environment and wildlife refuges. As tools and equipment continually improve and develop, the technology has been applied in many geologic formations, including oil and gas reservoirs and on sour wells, thus driving the need for globally accepted standards and safe operating best practices.

Managed Pressure Drilling Operations — Pressurized Mud Cap Drilling with a Subsea Blowout Preventer

1. Scope

   This document addresses recommended practices for pressurized mud cap drilling (PMCD) from a floating rig with a subsea BOP stack. When massive lost circulation conditions are encountered, PMCD can be implemented to allow well construction operations to continue:

   
   

   Although this document only addresses PMCD, most of the equipment described may also be used for the surface back-pressure (SBP) method of managed pressure drilling. However, much of the equipment used for SBP is not required for PMCD, and will not be covered here.

   
   

   The following methods, described briefly, are also used during lost circulation conditions; however, they are outside the scope of this document:

   1. blind drilling (see 4.3.2);

   2. continuous annular injection drilling (see 4.3.3);

   3. floating mud cap drilling (see 4.3.4).

   
   

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 Standard 2RD, Dynamic Risers for Floating Production Systems

API Recommended Practice 16Q, 1st Edition, Recommended Practice for Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems

3 Terms, Definitions, and Abbreviations

3.1 Terms and Definitions

For the purposes of this document, the following terms and definitions apply.

3.1.1

blind drilling

A method where fluid is pumped down the drill string with no returns up the annulus.

3.1.2

common well barrier element

Barrier element that is shared between the primary and secondary barrier envelopes.

3.1.3

continuous annular injection

A method where fluid is continuously pumped down the drill string and the annulus.

3.1.4

equivalent circulating density ECD

Equivalent circulating density is the effective density of the circulating fluid in the wellbore resulting from the sum of the pressure imposed by the static fluid column, friction pressure, and surface back-pressure.