The Blocks and Drilling Line

Transcription

1 rotary drilling series Unit I, Lesson 5 The Blocks and Drilling Line Third Edition, Revised By L. D. Davis Published by PETROLEUM EXTENSION SERVICE The University of Texas at Austin Division of Continuing & Innovative Education Austin, Texas Originally produced by INTERNATIONAL ASSOCIATION OF DRILLING CONTRACTORS Houston, Texas 2013 i

2 Library of Congress Cataloging-in-Publication Data Davis, L.D The blocks and drilling line / L.D. Davis. 3rd ed. p. cm. (Rotary drilling series ; unit 1, lesson 5) ISBN (pbk.) 1. Oil well drilling Equipment and supplies. 2. Pulleys. 3. Wire rope. I. Title. II. Series. TN871.5.D '.3381 dc CIP Disclaimer Although all reasonable care has been taken in preparing this publication, the authors, the Petroleum Extension Service (PETEX ) of The University of Texas at Austin, and any other individuals and their affiliated groups involved in preparing this content, assume no responsibility for the consequences of its use. Each recipient should ensure he or she is properly trained and informed about the unique policies and practices regarding application of the information contained herein. Any recommendations, descriptions, and methods in this book are presented solely for educational purposes (Revised 2013) by The University of Texas at Austin All rights reserved First Edition published Third Edition published 1996 Sixth impression 2013 Printed in the United States of America This book or parts thereof may not be reproduced in any form without permission of Petroleum Extension Service, The University of Texas at Austin. Graphic Designer: Debbie Caples 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 ISBN No state tax funds were used to publish this book. The University of Texas at Austin is an equal opportunity employer. ii

3 Figures Tables vii viii contents Foreword ix Acknowledgments Units of Measurement xi xii Introduction 1 Derricks versus Masts 2 Hoisting System Components 2 Top Drives 3 Blocks 4 Drilling Line 4 Deadline Tie-Down Anchor 4 Lifting and Lowering 5 Drilling Line, Crown Block, and Traveling Block 6 To Summarize 6 Installing the Line 7 Pulling Line from the Supply Reel 7 Reeving the Crown Block 8 Reeving the Traveling Block 8 Reeving between the Crown Block and the Traveling Block 8 Taking in Line on the Drawworks 9 Securing the Deadline 9 Using the Hoisting System 9 System Overview 10 To Summarize 14 Service Life 15 Factors that Affect Service Life 15 Derrick Height 15 Sheave Size 16 Line Tension 16 Drawworks Drum 17 Deadline Tie-Down Anchor 18 Handling 18 Drilling Job Type 18 To Summarize 18 Drilling Line Construction 19 Wire-Rope Steel 20 Preforming 20 Design 21 Cores 21 Strands 21 Construction 21 Single Layer 22 iii

4 Filler Wire 22 Seale 22 Warrington 22 Combination 22 Wire-Rope Lay 24 Ordering Wire Rope 25 Selection 25 Diameter 25 Length 27 Slip-and-Cut Programs 28 Slipping 29 Cutting 29 Cost Versus Line Length 30 To Summarize 31 Reeving 33 Reeving Pattern 33 Number of Lines 36 Other Factors 36 Fleet Angle 37 Reeving Using Old Line 38 Reeving Using a Catline 41 To Summarize 42 Drum Spooling 43 Types of spooling 44 Helical Grooving Pattern 44 One-Step Grooving Pattern 45 Two-Step, or Counterbalance, Spooling 46 Two-Step Spooling with Soft Crossover 47 To Summarize 48 Measuring Service Life 49 Slip and Cutoff 49 Slipping 50 Planning Slipping and Cutoff 53 Cutting 54 Procedure for Slip and Cutoff 57 Using Charts 58 Visual Inspection 61 To Summarize 62 Care of Wire Rope 63 Care at the Supply Reel 63 Minimizing Stress 65 Minimizing Scrubbing 66 Care at the Drum 66 Lubrication 68 Factory Lubrication 68 iv

5 Field Lubrication 68 To Summarize 70 Visual Inspection 71 To Summarize 72 Blocks and Hook 73 Load Capacity 76 Sheaves 76 Sheave Construction 76 Groove Radius 77 Tread Diameter 78 Crown Block 80 Traveling Block 82 Traveling Block Design 84 Hook 84 Combination Hook-Block 86 To Summarize 88 Elevators 89 Bottleneck Elevators 90 Collar-Lift or Square Shoulder Elevators 91 Elevator Design, Size, and Latches 91 To Summarize 92 Care of Blocks, Hook, and Elevators 93 Lubrication of Blocks and Hook 93 Sheaves 94 Visual Inspection of Blocks and Drilling Line 95 Visual Inspection of Hook Assembly 96 Hydraulic Snubber Oil Level 97 Elevator Lubrication and Inspection 97 Elevator-Link Check 99 To Summarize 99 Conclusion 101 Appendix A: Calculating Ton-Miles (Megajoules) of Drilling Line Service 103 Appendix B: Slip-and-Cutoff Programs 113 Appendix C: Troubleshooting Drilling Line Problems 116 Glossary 117 Review Questions 127 Answers to Review Questions 139 v

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7 introduction Introduction In this chapter: The difference between a derrick and a mast The drawworks and crown block How a top-drive system works The central function of the blocks and drilling line Lifting loads and stresses Lifting, or hoisting, subsurface equipment is a basic part of drilling. Crewmembers run and pull core samples, fishing tools, and testing tools. They also run and pull casing, drill bits, and thousands of feet (metres) of drill pipe as the hole gets deeper. Without a hoist ing system, rotary drilling could not happen. Several key components make up the hoisting system: drawworks, a mast or a derrick, a crown block, a traveling block, and a wire-rope drilling line all work in conjunction to drill a hole (fig. 1). The hoisting system helps the crew to run and pull: Core samples Fishing tools Testing tools Casing Drill bits Drill pipe A derrick (a standard derrick) is a tower that crewmembers as sem ble piece by piece. A mast, on the other hand, is a portable derrick that a manufacturer assembles once and sells as a one-piece unit. Most drilling rigs use a mast. Almost everybody in the drilling indus try, however, calls a mast a derrick. This book does the same. Derricks Versus Masts 1

8 The blocks and Drilling Line CROWN BLOCK WIRE ROPE DRILLING LINE TRAVELING BLOCK DRAWWORKS DERRICK Figure 1. The hoisting system Hoisting System Components The drawworks is a large winch with a drum. (For a detailed discussion of the drawworks, see Lesson 6, The Drawworks and the Compound.) Crewmembers spool the drilling line onto it. The drilling line runs from the drawworks to the crown block. The line then goes through the traveling block and suspends it in the derrick (see fig. 1). The manufacturer attaches a large hook and adds two protrusions (ears) to the travel ing block. Crewmembers insert the two links (bails) of a pipe-gripping device the elevators into the traveling block s ears. They also latch a swivel into the hook, using a bail on the swivel. The swivel s bail is like the bail (the handle) on a bucket, only much bigger. Crewmembers make up (connect) the kelly and drill pipe to the swivel when making hole (fig. 2). The elevators grip stands of pipe when coming out of the hole (fig. 3). 2

9 introduction CROWN BLOCK DRILLING LINES TRAVELING BLOCK EARS DRILLING HOOK SWIVEL ELEVATORS BAILS TOP DRIVE KELLY ASSEMBLY ELEVATORS DRILL PIPE DRILL PIPE Figure 3. Elevators latched to drill pipe DRILL STEM BIT Figure 2. Hook, swivel, and kelly assembly Figure 4. Top-drive system Instead of a conventional swivel, some hooks suspend a top-drive system (fig. 4). The top drive has a powerful motor that turns the drill stem. A top drive is somewhat like a pow ered swivel, because it has a motor. Crewmembers attach the top of the drill stem to a drive shaft in the top drive. The top drive s motor turns the drive shaft, the drill stem, and the bit. Rigs with top drives do not use a kelly or the rotating parts of the rotary table. Top Drives 3

10 The blocks and Drilling Line Blocks With or without a top drive, the blocks and drilling line are central to the hoisting system. Rigs use two blocks. One is the crown block and the other is the traveling block. The crown block is at the top of the derrick. The driller moves the traveling block up and down the derrick between the crown block and the rig floor. Both blocks are two giant pulleys that have high-strength wire-rope drilling line running between them. Drilling Line Manufacturers make drilling line by braiding together several strands of high-strength steel. Rig hands reeve (thread) this wire rope between the crown block and the traveling block. They run it back and forth from the crown block to the traveling block several times. The more times the workers string the line between the two blocks, the more weight the hoisting assembly can lift. Reeving several lines multiplies the line s lifting capacity. After reeving the line, workers attach one end of it to the drawworks drum. They attach the other end to the deadline tie-down anchor. Deadline Tie-Down Anchor The deadline tie-down anchor: Grips one end of the drilling line Mounts the weight indicator s sensing device The weight indicator shows hook load and weight on bit. The deadline tie-down anchor firmly grips one end of the drilling line and keeps it from moving (fig. 5). It is a strong, rugged device that crewmembers usually bolt to the rig s substructure or to another heavy, stationary part of the rig. Besides anchoring the drilling line, the anchor also serves as a mount for the weight indicator s sensing device. The weight indicator, which is on the driller s console, tells the driller how much the hook load is and how much weight is on the bit. (Hook load is how much weight is hanging from the hook. Weight on the bit is how much drill stem weight is pressing on the bit.) The weight indicator s sensor is a special strain gauge. As the weight of the load on the deadline flexes the deadline, the sensor picks up the flexes and sends a signal to the weight indicator on the rig floor. The weight indicator then translates the signal into weight on the bit and the hook load. 4

11 introduction DEADLINE TO CROWN BLOCK TO SUPPLY REEL LOAD SENSOR HYDRAULIC LINE (HOSE) TO WEIGHT INDICATOR BOLTS MOUNT ANCHOR TO RIG Figure 5. Deadline tie-down anchor With one end of the line firmly fastened to the anchor and the other end attached to the drawworks drum, the driller can reel in the drilling line with the drawworks. Reeling in the line lifts the traveling block and whatever is attached to it. Letting out line lowers the traveling block. The drawworks brake controls the block s descent. Lifting and Lowering 5