Recommended Practice for the Design of Solution-mined Underground Storage Facilities

API RECOMMENDED PRACTICE 1114 SECOND EDITION, JANUARY 2013

Recommended Practice for the Design of Solution-mined Underground Storage Facilities

Downstream Segment

API RECOMMENDED PRACTICE 1114 SECOND EDITION, JANUARY 2013

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 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 Recommended Practice 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, 1220 L Street, NW, Washington, DC 20005.

Copyright © 2013 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

1. Scope 1

2. Normative References 1

3. Terms and Definitions 1

4. Overview of Underground Storage 6

5. Applicable Rules and Regulations 6

6. Salt Storage Overview 6

   1. General 6

   2. Components 8

7. Design Parameters 9

   1. General 9

   2. Available Salt Formations 9

   3. Product Characteristics 9

   4. Storage Volume Required 10

   5. Displacement-fluid Characteristics 10

8. Required Knowledge of Salt Structure and Associated Geology 11

   1. General 11

   2. Geometry of the Salt Formation 11

   3. Faulting and Structural Anomalies 12

   4. Overburden Structure 12

   5. Location of Nearby Existing Caverns 12

   6. Salt Properties 12

9. Cavern Design Criteria 13

   1. General 13

   2. Setting Cavern Depth 13

   3. Cavern Shape Considerations 13

   4. Cavern Spacing Constraints 14

10. Cavern Hydraulics 15

    1. Static Pressure 15

    2. Flowing Pressure Drop 16

11. Equipment and Materials 26

    1. Wellhead 26

    2. Casings and Tubing Strings 26

    3. Cement 27

12. Drilling and Completion 27

    1. General 27

    2. Preliminary Considerations 29

    3. Borehole Development 29

    4. Mud Program 30

    5. Cement Program 30

    6. Casing and Cement Placement 31

    7. Cement Placement 31

    8. Testing Prior to String Placement 32

       v

       
       

13. Solution Mining 32

    1. Basic Concepts 32

    2. Solution-mining Techniques 33

    3. Factors Affecting the Solution-mining Program 34

    4. Wash and Solution-mining Strings 34

    5. Control of Cavern Development 38

    6. Monitoring Cavern Growth 42

    7. Conversion from Solution Mining to Product Storage 43

14. Cavern Integrity and Testing 43

    1. Testing Requirements and Purpose 43

    2. Test Pressure Level 43

    3. Nitrogen and Brine Test 43

    4. Liquid Pressure Test 44

    5. Supplementary Information 45

    6. Regulatory Considerations 45

    7. Final Report and Records Retention 45

15. Cavern Abandonment 45

    1. Overview 45

    2. Action Required to Abandon Well 46

Bibliography 47

Figures

1. Simplified Salt Dome Storage Cavity Schematic 7

2. Wellhead Pressure Versus Flow Rate 22

3. Brine String Pressure Drops 25

4. Solution-mining: Direct-circulation Method 35

5. Solution-mining: Reverse-circulation Method 36

6. Solution-mining Methods 37

Recommended Practice for the Design of Solution-mined Underground Storage Facilities

1. Scope

   
   

   This recommended practice (RP) provides basic guidance on the design and development of new solution-mined underground storage facilities. It is based on the accumulated knowledge and experience of geologists, engineers, and other personnel in the petroleum industry. Users of this guide are reminded that no publication of this type can be complete nor can any written document be substituted for qualified, site-specific engineering analysis.

   
   

   All aspects of solution-mined underground storage are covered, including selecting an appropriate site, physically developing the cavern, and testing and commissioning the cavern. Additionally, a section on plug and abandonment practices is included.

   
   

   This RP does not apply to caverns used for natural gas storage, waste disposal purposes, caverns which are mechanically mined, depleted petroleum reserve cavities, or other underground storage systems which are not solution-mined.

   
   

   See API 1115 for guidance in the operation of solution-mined underground storage facilities.

   
   

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 Recommended Practice 5A3, Recommended Practice on Thread Compounds for Casing, Tubing, and Line Pipe

   
   

   API Recommended Practice 5C1, Recommended Practice for Care and Use of Casing and Tubing

   
   

   API Bulletin 5C3, Bulletin on Formulas and Calculations for Casing, Tubing, Drill Pipe, and Line Pipe Properties

   
   

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

   
   

   API Standard 1104, Welding of Pipelines and Related Facilities

   
   

   API Recommended Practice 1115, Recommended Practice on the Operation of Solution-Mined Underground Storage Facilities

   
   

   ASME1 , Boiler and Pressure Vessel Code, Section IX, “Welding and Brazing Qualifications”

   
   

3. Terms and Definitions

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

3.1

blanketing material

A fluid less dense than water and incapable of dissolving salt.

NOTE This is usually a light hydrocarbon liquid injected as a protective barrier between the solution-mining brine and casing- salt interface is usually used to control cavern development.

1 ASME International, 3 Park Avenue, New York, New York 10016-5990, www.asme.org.

1