PIPELINE PIGGING TECHNOLOGY 2nd Edition, 1992 Edited by J.N.H.Tiratsoo BSc, CEng, MICE, MIWES, MICorr, MIHT J_ Gulf Professional Publishing H an imprint of Butterworth-Heinemann Copyright © 1999 by Butterworth-Heinemann. All rights reserved. Printed in the United States of America. This book, or parts thereof, may not be reproduced in any form without permission of the publisher. Originally published by Gulf Publishing Company, Houston, TX. 10 9 8 For information, please contact: Manager of Special Sales Butterworth-Heinemann 225 Wildwood Avenue Woburn, MA 01801-2041 Tel: 781-904-2500 Fax: 781-904-2620 For information on all Butterworth-Heinemann publications available, contact our World Wide Web home page at: http://www.bh.com Library of Congress Cataloging-in-Publication Data Pipeline Pigging Technology / edited by J.N.H.Tiratsoo - 2nd ed. p. cm. ISBN 0-87201-426-6 1. Pipeline pigging. I. Tiratsoo, J.N.H. TJ930.P5665 1991 621.8'672-dc20 91-30538 CIP Typeset in ITC Garamond 11/12pt Printed by Nayler The Printer Ltd, Accrington, UK The cover design, based on that used for the first edition, was originated by Premaberg Services Ltd. vl They roll and rumble, They turn and tumble, Asptgges do in a poke. Sir Thomas More, Works, 1557 How a Sergeant would learn to Play the Frere vii AUTHORS AND SOURCES Parti 3-16 Dr A Palmer and T Jee US2 Andrew Palmer & Associates Ltd, UK 17-30 J L Cordell REHAB Pigging Products & Services Association, UK 31-36 J C Caldwell US3 Joseph Caldwell & Associates, USA 37-46 J C Caldwell REHAB Joseph Caldwell & Associates, USA 47-54 C Bal US1 H Rosen Engineering BV, Netherlands 55-66 C Bal US2 H Rosen Engineering BV, Netherlands 67-78 J M Neffgen US2 Stena Offshore Ltd, UK 79-90 G Robinson US3 Ecology & Environment Inc, USA Part 2 93-114 T Deshayes1 and M Park2 UK1 'Total Oil Marine pic and 2Scicon Ltd, UK 115-128 PJ Brown US2 Total Oil Marine pic, UK 129-142 JMaribu US2 Statoil, Norway 143-162 TSowerby UK2 British Gas pic On-Line Inspection Centre, UK 163-178 M S Keys1 and R Evans2 US3 'Dowell Schlumberger Inc and 2Missouri-Omega Pipelines, USA 179-188 J C Harle US3 Alyeska Pipeline Service Co, USA 189-204 DMRamsvigJ Duncan and LZillinger US3 Nova Corporation, Canada 205-212 ABarden UK2 McKenna & Sullivan, UK xv Part 3 215-222 GL Smith US1 Knapp Polly Pig, USA 223-236 Dr JS Smart1 and GL Smith2 UK2 ^elchem Inc and 2Knapp Polly Pig, USA 237-242 CKershaw UK2 McAlpine Kershaw, UK 243-250 AEvett US1 Nowsco Pipeline Surveys and Services, UK 251-258 AEvett US2 Nowsco Pipeline Surveys and Services, UK 259-284 AAPennington UK2 Vetco Pipeline Services, USA 285-302 A Met1, R van Agthoven1 and J A de Raad2 US3 ^TD, Inc, Canada, and 2RTD BV, Netherlands 303-324 DrP Hopkins UK2 British Gas pic Engineering Research Station, UK 325-334 N Sugaya, K Murashita, M Koyayashi, S Ishida and H Akuzawa US2 NKK Corporation Pipeline Inspection Services, Japan 335-342 HGoedecke US2 Pipetronix GmbH, Germany 343-364 H A Anderson1, P St J Price1, J W K Smith2 and R L Wade2 UK2 JPigco Pipeline Services and 2Pulsearch Consolidated Technology, Canada 365-384 T Jee, M Carr and Dr A Palmer UK2 Andrew Palmer & Associates Ltd, UK 385414 L A Decker1, R E Hoepner2 and W S Tillinghast3 US3 ^ydroTech Systems Inc, transcontinental Gas Pipeline Corp and 3Conoco Inc, USA xvl Part 4 417-424 D Storey and P Moss US2 British Gas pic On-Line Inspection Centre, UK 425440 M Urednicek, RI Coote and R Coutts US3 Nova Corporation, Canada 441446 C Klein US3 UCISCO, USA Part 5 449460 J L Cordell US3 Pigging Products & Services Association, UK Key to conferences UKl Pipeline pigging and integrity monitoring, Aberdeen, Feb 1988 UK2 Pipeline pigging and integrity monitoring, Aberdeen, Nov 1990 US1 Pipeline pigging and inspection technology, Houston, Feb 1989 US2 Pipeline pigging and inspection technology, Houston, Feb 1990 US3 Pipeline pigging and inspection technology, Houston, Feb 1991 REHAB Pipeline risk assessment, rehabilitation and repair, Houston, May 1991 xvli FOREWORD THIS SECOND, completely-revised, edition of Pipeline Pigging Technol- ogy is essentially a compilation of selected papers presented at the confer- ences organized by Pipes & Pipelines International and Pipe Line Industry in the UK and the USA between 1988 and 1991. The book is thus a successor to the first edition, published in 1987, and brings readers up-to-date with the rapidly-developing technology of pipeline pigging. Although the international pigging industry has unquestionably made major advances in its scope and expertise over the intervening years, it is nevertheless apparent that the comment made in the earlier book - that there is a general lack of knowledge about the use of pipeline pigs of all kinds - is still relevant today. Not only have the conferences at which these papers were presented produced questions such as 'How do I interpret the results of this intelligent pigging inspection?', but they also continue to produce the most basic of pigging questions such as 'Should I use discs or cups?' or 'Will foam pigs or rigid pigs work the best in this application?'. It cannot be claimed that this book will provide readers with the answers to all their questions; indeed, many such answers remain in the experimental field of 'try it and see'. Nevertheless, we have gathered together in this edition a collection of 33 papers which give a comprehensive overview of the current situation, written by respected authors, from whom further information can undoubtedly be readily obtained by seriously-interested readers and organiza- tions. It is significant to note that, in early October, 1991, the first-ever major research project into the performance of 'conventional' pigs was entering its second phase. At the same time, the Pigging Products and Services Association was developing into a healthy organization with increasing membership, while the world's first long-distance gas pipeline designed with a total commitment to intelligent pigging was being constructed in the North Sea. These three discrete activities show that the hydrocarbons pipeline industry is paying increasing interest to pigging, which is seen, more-and-more widely, as an important aspect of future pipeline operations. xvlii Readers will find in this book papers that cover subjects more diverse than simply the practicalities of pigging. I make no apology for this, as the basic requirements for pigging have now to be seen in a wider context, the boundaries of which are increasingly being set by legislation. Concepts such as 'fitness-for-purpose' and 'integrity management', the practical develop- ment of which will allow an operator to manage his pipeline with greater precision and safety, will nevertheless be based on data obtained from successful pigging operations. On page xii will be found a list of the contributors, together with references to the conferences at which their papers were originally pre- sented. I am greatly indebted to all these authors, both for their willingness to participate in the conferences, and for their agreement to allow their papers to be published in this book. It should be explained that, although edited as far as possible into a uniform appearance, the papers appear here in the same form as that in which they were originally presented. Any errors are, of course, my own. John Tiratsoo, October, 1991 xlx Why pig a pipeline? WHY PIG A PIPELINE? INTRODUCTION Why pig a pipeline? This paper introduces a number of reasons for doing so, together with a discussion of the advantages and alternatives. In general terms, however, pigging is not an operation to be undertaken lightly. There are often technical problems to be resolved and the operation requires careful control and co-ordination. Even then, there is always a finite risk that a foreign body introduced into the pipeline will become lodged, block the flow and have to be cut out with all the operational expense and upset which would accompany such an incident. The pipeline operator must therefore give serious consideration to whether his line really needs to be pigged, whether it is suitable to be pigged, and whether it is economic to do so. The name pig was originally applied to Go-Devil scrapers which were devices driven through the pipeline by the flowing fluid trailing spring-loaded rakes to scrape wax off the internal walls. The rakes made a characteristic loud squealing noise, hence the name "pig" which is now used to describe any device made to pass through a pipeline driven by the pipeline fluid. A large variety of pigs has now evolved, some of which are illustrated in Fig.l. They typically perform the following functions: separation of products cleaning out deposits and debris gauging the internal bore location of obstructions meter loop calibration liquids' removal gas removal pipe geometry measurements internal inspection coating of internal bore corrosion inhibition improving flow efficiency Pipeline Pigging Technology Fig.l. Typical types of pig. As new tools and techniques are developed, the above list is expanding, and has come to include self-propelled and tethered devices such as piggable barrier valves and pressure-resisting plugs. The following paragraphs consider a pipeline from construction through to operation and maintenance, looking at possible requirements for pigging. 4