Casing and Cementing Preview b

Rotary Drilling

CASING

AND CEMENTING Third Edition

Unit II, Lesson 4

ROTARY DRILLING SERIES



Casing and Cementing Unit II, Lesson 4 Third Edition

  

By William E. Jackson Published by PETROLEUM EXTENSION SERVICE Continuing & Extended Education The University of Texas at Austin Austin, Texas in cooperation with INTERNATIONAL ASSOCIATION OF DRILLING CONTRACTORS Houston, Texas 2001

Library of Congress Cataloging-in-Publication Data Feder, Judy, 1950— Casing and cementing / by Judy Feder. — 3rd ed. p. cm. — (Rotary drilling series ; unit 2, lesson 4) ISBN 0-88698-191-3 (alk. paper) 1. Oil well casing. 2. Oil well cementing. I. Title. II. Series. TN871.22.F44 2001 622'.3381—dc21 2001000765 CIP

©2001 by The University of Texas at Austin All rights reserved First Edition published 1968. Second Edition 1982. Third Edition 2001. Second Impression 2007 Printed in the United States of America This book or parts thereof may not be reproduced in any form with­ out permission of Petroleum Extension Service, The University of Texas at Austin. Brand names, company names, trademarks, or other identifying symbols appearing in illustrations and/or text are used for educational purposes only and do not constitute an endorsement by the author or the publisher. Catalog no. 2.20430 ISBN 0-88698-191-3 No state tax funds were used to publish this book. The University of Texas at Austin is an equal opportunity ­employer.

Figures Tables

Contents

v viii

Foreword

vii

Acknowledgments Units of Measurement Introduction Casing

  

ix x

1

3

Casing Strings

4

Types of Casing 5 Conductor Pipe 6 Surface Casing 7 Intermediate Casing 7 Liner String 8 Production Casing 10 To Summarize 11 String Design 12 Design Criteria: Primary Forces 12 Design Criteria: Secondary Forces 15 Design Criteria: Downhole Environment To Summarize 16 Setting the Casing 17 Preparation 17 Running the Casing 22 Stabbing, Making Up, and Lowering Landing 32 API Standards 36 To Summarize 41

27

Casing Threads and Couplings 42 Proprietary or Premium Connections To Summarize 48

45

Changing Technology Cementing

15

49

51

Primary Cementing Basics To Summarize 54

52

Oilwell Cements and Additives Additives 57 Special Cements 62 To Summarize 64

55

Mixing 66 Water Quality 66 Water Quantity 66 Types of Mixers 67

iii

Pumping 70 Displacing the Drilling Mud Pumping the Cement 71 Casing Accessories 73 To Summarize 79

70

Cement Volume Requirements 81 Calculating Open-Hole Capacity To Summarize 83 Considerations After Cementing 84 Waiting on Cement 84 Checking the Cement Top 85 Pressure Testing 87 To Summarize 87 Glossary

89

82

1. These joints of casing are ready to be run into the well, where they will serve at least seven important functions. 3 2. Most wells require several strings of casing, each of which serves a specific purpose important to the completion of the well. 5 3. Conductor pipe in offshore operations extends the “hole” from the seafloor, up through the water, to a point in the air just below the drilling deck. 6

Figures   

4. A liner is a relatively short string of casing that extends from the bottom of the open hole, up into another string. 8 5. Liner strings are nearly always suspended from the upper string by means of a liner hanger. 8 6. A tie-back string from the liner to the surface may be used if an existing casing string has been weakened by drilling. 9 7. Whether on or offshore, preventive maintenance is key to protecting casing as it is prepared to run into the well. 17 8. A thread protector should be in place any time a joint of casing is handled. 18 9. Casing resting on stringers

19

10. Before casing is run, threads are inspected for damage that may have occurred during shipping and racking. 20 11. Pipe is tallied three times: when it is shipped, when it arrives at location, and after the casing string has been run. 22 12. Running casing

23

13. Stabbing casing

24

14. Special bucket and sling arrangement raise a joint of casing to the rig floor 27 15. Thread compound may be applied over the entire surface of the casing threads just before stabbing. 28 16. Hydraulic power tongs are placed around a joint of casing to make it up to a predetermined torque. 29 17. Casing elevators and casing spider support the casing as it is being lowered into the well. 31 18. Landing the casing involves transferring the casing string weight to the wellhead, usually with a casing hanger that seats in the casinghead and seals the annulus between the outer and inner strings. 32 19. Downhole casing hangers are used to relieve some of the load on the casinghead. 35 20. Casing with a coupling (A) and a threaded end (B) 21. Examples of API-threaded connections

42

43

22. Examples of premium-threaded connections

45

v

23. Halliburton cementing equipment from the 1920s

51

24. Primary cementing is performed immediately after the casing has been run in the hole, to seal and separate each zone, and to protect the pipe. 53 25. Cementing trucks transport dry cement blends to the well site. 55 26. High-energy recirculating mixers provide thoroughly mixed slurries at a wide range of densities and rates. 67 27. Internal operation of a recirculating mixer

68

28. The demands and expense associated with offshore operations have led to the development of sophisticated, high-tech mixing and data acquisition systems. 68 29. Internal operation of a batch mixer 30. A primary cementing job

69

71

31. Wiper plugs are placed in the cementing head to wipe mud off the inside of the casing and keep it separated from the cement. 72 32. A typical casing string with accessories 33. A guide shoe

73

74

34. An automatic fill-up shoe

74

35. A float collar prevents backflow of cement during the cementing operation. 75 36. Multistage cementing devices are used to cement two or more separate sections behind a casing string. 76 37. Bow (A) and solid body (B) centralizers

77

38. Scratchers (A) and wipers (B) help remove filter cake and gelled mud from the well as the casing is run. 78 39. Temperature survey showing the top of cement outside the casing 85

Tables   

1. Fluid Displacement of Casing

25

2. Volume Gains in the Mud Pit from Casing Displacement 3. API Length Ranges of Casing

36

4. Specification for Casing and Tubing—API Casing List

37

5. Specification for Casing and Tubing—Tensile and Hardness Requirements 39 6. Distance Between Plates for Electric Weld Flattening Tests 40 7. Effects of Some Additives on the Physical Properties of Cement 58

vi

25

Foreword   

F

or many years, the Rotary Drilling Series has oriented new personnel and further assisted experienced hands in the rotary drilling industry. As the industry changes, so must the manuals in this series reflect those changes. The revisions to both the text and illustrations are extensive. In addition, the layout has been “modernized” to make the information easy to get; the study questions have been rewritten; and each major section has been summarized to provide a handy comprehension check for the reader. PETEX wishes to thank industry reviewers—and our readers— for invaluable assistance in the revision of the Rotary Drilling Series. Casing and Cementing introduces rig crew members to the concept of casing string design and the procedures for properly handling pipe while it is on the rack, being picked up, made up into a string, and cemented in the hole. This manual covers types of pipe usually employed, string design considerations, running techniques, cementing procedures, casing liner use, liner setting, and cement strength determination. Although every effort was made to ensure accuracy, this manual is intended only as a training aid; thus, nothing in it should be construed as approval or disapproval of any specific practice or product.

Ron Baker

vii

Acknowledgments   

T

he author expresses a sincere appreciation to the numerous people who have helped with the preparation of this edition of Casing and Cementing. In particular, special thanks go to Rick Covington of Halliburton Energy Services, and Ed Banker of Marubeni Tubulars, Inc. Their time and patience reviewing the manuscript and updating information was invaluable. Thanks also go to Monte Montague, Betsy Mott, and Dave Rees of Halliburton, as well as Anjali Prasad and John Greenip of Hydril, for locating and providing illustrations and photographs for use in the manual. John Greenip was most helpful in providing assistance in reviewing the text. All who have contributed time, thought, and effort into this book have worked to make this new edition a success in providing the most complete information about casing and cementing.

ix

Units of Measurement   

T

hroughout the world, two systems of measurement dominate: the English system and the met­ric system. To­day, the United States is almost the only country that employs the En­glish sys­tem. The English system uses the pound as the unit of weight, the foot as the unit of length, and the gallon as the unit of capacity. In the En­glish system, for example, 1 foot equals 12 inches, 1 yard equals 36 inches, and 1 mile equals 5,280 feet or 1,760 yards. The metric system uses the gram as the unit of weight, the metre as the unit of length, and the litre as the unit of capacity. In the metric system, for example, 1 me­tre equals 10 decimetres, 100 centimetres, or 1,000 milli­metres. A kilometre equals 1,000 me­tres. The metric system, un­like the English system, uses a base of 10; thus, it is easy to convert from one unit to another. To convert from one unit to an­other in the English system, you must memorize or look up the val­ues. In the late 1970s, the Eleventh General Conference on Weights and Measures de­scribed and adopted the Système International (SI) d’U­nités. Conference participants based the SI system on the metric system and de­signed it as an interna­ tional stan­dard of measurement. The Rotary Drilling Series gives both English and SI units. And because the SI sys­tem employs the British spelling of many of the terms, the book follows those spelling rules as well. The unit of length, for ex­ample, is metre, not me­ter. (Note, however, that the unit of weight is gram, not gramme.) To aid U.S. readers in making and understanding the conversion to the SI system, we in­clude the following table.

x



Introduction   

C

asing and cementing are essential to drilling oil and gas wells. Lining a hole with casing keeps it from caving in after it is drilled, sealing the wellbore from encroaching fluids and gasses. Cementing the casing in place attaches it firmly to the wellbore wall and stabilizes the hole. Casing and cement both serve additional, important functions in the well. These functions will be addressed later in this manual. Casing and cementing procedures have grown more sophisticated in recent years as the search for new hydrocarbon-bearing reservoirs takes wells deeper and into more hostile environments (i.e., deep water, high pressures and temperatures, and sour gases). Engineers and metallurgists work continually to refine casing or cementing designs and procedures to handle the challenges associated with offshore and remote locations, extreme depths, and severe conditions. During the days of cable-tool drilling, numerous strings of casing had to be set as a well was drilled. With the advent of rotary drilling came better quality muds with greater ability to control well pressures. As a result, much more open hole could be drilled. Casing is now generally set to serve a specific purpose and is neither arbitrary nor compulsory for any hole conditions.



  

1



Casing   

C

asing and tubing account for 15 to 20 percent of the completed cost of a well—often the greatest single item of expense on the well. Failure of casing or tubing results in expensive rework and may lead to loss of the well, or worse, loss of life. Selecting casing sizes, weights, grades, and types of threaded connections for a given situation presents an engineering and economic challenge of considerable importance. Casing is strong steel pipe used in an oil or gas well to ensure a pressure‑tight connection from the sur­face to the oil or gas reservoir. Casing serves at least seven important func­tions in the well (fig. 1): 1.

It prevents the hole from caving in or washing out.

2.

It protects freshwater sands from contamination by fluids from lower zones.

3.

It keeps water out of the producing for­mation.

4.

It confines production to the wellbore.

5.

It contains formation pressures and prevents fracturing

Figure 1. These joints of casing are ready to be run into the well, where they will serve at least seven important functions.

3



Cementing   

O

ilwell cementing is the process of mixing and placing a cement slurry in the annular space be­tween a string of casing and the open hole. The cement sets, bonding the casing to the wall of the wellbore for additional stability. The practice of cementing began around 1903 in California. Early methods of mixing cement and placing it in the hole were quite crude. Modern cementing practices debuted in 1920, when Erle Halliburton cemented a well in Oklahoma’s Hewitt Field for W.G. Skelly (fig. 23). Today, the Halliburton jet mixer remains a basic device for rapid mixing of drilling mud, although it is seldom used for mixing cement slurry. In 1903 there was only one type of cement and no additives. Today there are eight classes of cement and more than 40 different addi­tives. Bulk‑cement handling is stan­dard practice, and blends are tailored to specific jobs. Waiting‑on‑cement time has been reduced from 10 days to less than 24 hours.

Figure 23. Halliburton cementing equipment from the 1920s (Courtesy of Halliburton)

51



Glossary   

accelerator n: a chemical additive that reduces the setting time of cement. See cement, cementing materials.

A

additive n: 1. in general, a substance added in small amounts to a larger amount of another substance to change some characteristic of the latter. In the oil in­dustry, additives are used in lubricating oil, fuel, drill­ing mud, and casing cement. 2. in cementing, a substance added to cement to change the cement characteristics to satisfy specific conditions in the well. A cement additive may work as an accelerator, retarder, dispersant, or other reactant. API gravity n: the measure of the density or gravity of liquid petroleum products in the United States; derived from relative density in accordance with the following equation: API gravity at 60°F = [141.5 ÷ relative density 60/60°F] – 131.5 automatic fill-up shoe n: a device that is installed on the first joint of casing and that automatically regulates the amount of mud in the casing. The valve in this shoe keeps mud from entering the casing until mud pressure causes the valve to open, allowing mud to enter the casing. axial compression n: pressure produced parallel with the cylinder axis when casing hits a deviation in the hole or a sticky spot and stops. The force pushing down on the pipe causes axial compression.

bending n: occurs when tension is increased on one side of the pipe while compression is increased on the other.

B

billet n: a solid steel cylinder used to produce seamless casing. The billet is pierced lengthwise to form a hollow tube that is shaped and sized to produce the casing. boot n: a tubular device placed in a vertical position, either inside or outside a larger vessel, through which well fluids are conducted before they enter the larger vessel. A boot aids in the separation of gas from wet oil. Also called a flume or conductor pipe. bottom wiper plug n: a device placed in the cement­ing head and run down the casing in front of cement to clean the mud off the walls of the casing and to pre­vent contamination between the mud and the cement.

89

rotary drilling series Unit I: The Rig and Its Maintenance esson 1: L Lesson 2: Lesson 3: Lesson 4: Lesson 5: Lesson 6: Lesson 7: Lesson 8: Lesson 9: Lesson 10:

The Rotary Rig and Its Components The Bit Drill String and Drill Collars Rotary, Kelly, Swivel, Tongs, and Top Drive The Blocks and Drilling Line The Drawworks and the Compound Drilling Fluids, Mud Pumps, and Conditioning Equipment Diesel Engines and Electric Power The Auxiliaries Safety on the Rig

Unit II: Normal Drilling Operations esson 1: L Lesson 2: Lesson 3: Lesson 4: Lesson 5:

Making Hole Drilling Fluids Drilling a Straight Hole Casing and Cementing Testing and Completing

Unit III: Nonroutine Operations esson 1: Controlled Directional Drilling L Lesson 2: Open-Hole Fishing Lesson 3: Blowout Prevention

Unit IV: Man Management and Rig Management Unit V: Offshore Technology esson 1: L Lesson 2: Lesson 3: Lesson 4: Lesson 5: Lesson 6: Lesson 7: Lesson 8: Lesson 9: Lesson 10:

Wind, Waves, and Weather Spread Mooring Systems Buoyancy, Stability, and Trim Jacking Systems and Rig Moving Procedures Diving and Equipment Vessel Inspection and Maintenance Helicopter Safety Orientation for Offshore Crane Operations Life Offshore Marine Riser Systems and Subsea Blowout Preventers

To obtain additional training materials, contact:

PETEX

The University of Texas at Austin Petroleum Extension Service 1 University Station, R8100 Austin, TX 78712-1100 Telephone: 512-471-5940 or 800-687-4132 FAX: 512-471-9410 or 800-687-7839 E-mail: [email protected] or visit our Web site: www.utexas.edu/ce/petex

To obtain information about training courses, contact:

PETEX

Houston training center The University of Texas 2700 W. W. Thorne Blvd. Houston, TX 77073 Telephone: 281-443-7144 or 800-687-7052 FAX: 281-443-8722 E-mail: [email protected] or visit our Web site: www.utexas.edu/ce/petex

2.20430 0-88698-191-3