Successfully reported this slideshow.

download

6,216 views

Published on

Pipeline and risers

Published in: Technology, Business

download

  1. 1. ELSEVIER OCEAN ENGINEERING BOOK SERIES VOLUME 3 PIPELINES AND RISERS > EXPORT PIPELINE EXISTING PIPEUNE TO SHORE / Yong Bai SERIES EDITORSR. BHATTACHARYYA & M.E. McCORMICK
  2. 2. ELSEVIER OCEAN ENGINEERING BOOK SERIES VOLUME 3 PIPELINES AND RISERS
  3. 3. Elsevier Seience Internet Homepage http://www.elsevier.n1 (Europe) http://www.elsevier.com (America) ’ http://www.elsevier.colip (Asia)Consult the Elsevier homepage for full catalogue information on all books,journals and electronic products and services.Elsevier Titles of Related InterestBJORHOVDE, COLSON & ZANDONMI OWENSConnections in Steel Structures 111. Steel in Construction (CD-ROM Proceedings with PrintedISBN: 008-042821-5 Abstracts Volume, 268 papers). ISBN: 008-042997-1CHAN & TENGICASS ‘99, Advances in Steel Structures SRIVASTAVA(2 Volume Set). Structural EngineeringWorld Wide 1998 (CD-ROMISBN: 008-043015-5 Proceedings with Printed Abstracts Volume 702 papers). ISBN: 008-042845-2DUBINA -SDSS ‘99 Stability and Ductility of Steel Structures. USAMI & ITOH Stability and Ductility of Steel Structures.ISBN: 008-043016-3 ISBN: 008-043320-0FRANGOPOL, COROTIS & RACKWITZReliability and Optimization of Structural Systems. VASSALOSISBN: 008-042826-6 Contemporary Ideas on Ship Stability. ISBN: 008-043652-8FUKUMOTOStructural Stability Design. VUGTSISBN: 008-042263-2 BOSS ‘97 Behaviour of Offshore Structures (3 Volume Set). ISBN: 008-042834-7GODOYThin-Walled Structures with Structural Imperfections: WATSONAnalysis and Behavior. Practical Ship Design.ISBN: 008-042266-7 ISBN: 008-042999-8GUEDES-SOARES YOUNGAdvances in Safety and Reliability (3 Volume Set). Wind Generated Ocean Waves.ISBN: 008-042835-5 ISBN: 008-043317-0MOAN & BERGE OHTSUBO & SUM113th Int Ship & Offshore Structures Congress Proceedings of the 14th International Ship and Offshore(Issc 1997). StructuresCongress.ISBN: 008-042829-0 ISBN: 008-043602-1Related JournalsFree specimen copy gladly sent on request. Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington,Oxjord, OX5 I GB, UKApplied Ocean Research Engineering StructuresAdvances in Engineering Software Finite Elements in Analysis and DesignCAD International Journal of Solids and StructuresCoastal Engineering Journal of Constructional Steel ResearchComposite Structures Marine StructuresComputers and Structures NDT & E InternationalConstruction and Building Materials Ocean EngineeringEngineering Failure Analysis Structural SafetyEngineering Fracture Mechanics Thin-Walled StructuresTo Contact the PublisherElsevier Science welcomes enquiries concerning publishing proposals: books, journal special issues, conferenceproceedings, etc. All formats and media can be considered. Should you have a publishing proposal you wish to discuss,please contact, without obligation, the publisher responsible for Elsevier’s civil and structural engineering publishingprogramme: Ian Salusbury Senior Publishing Editor Elsevier Science Ltd The Boulevard, Langford Lane Phone: +44 1865 843425 Kidlington, Oxford Fax: +44 1865 843920 OX5 IGB, UK E.mai1: i.salusbury@elsevieLco.ukGenerdl enquiries, including placing orders, should be directed to Elsevier’s Regional Sales O f c s - please access the fieElsevier homepage for full contact details (homepage details at the top of this page).
  4. 4. ELSEVIER OCEAN ENGINEERING BOOK SERIES VOLUME 3 PIPELINES AND RISERS YONG BAIStavanger University College, N-409 1 Stavanger, Norway andAmerican Bureau of Shipping, Houston, TX 77060, USA OCEAN ENGINEERING SERIES EDITORS R. Bhattacharyya US Naval Academy, Annapolis, MD, USA M.E. McCormick The Johns Hopkins University, Baltimore, MD, USA ELSEVIER Amsterdam - London - New York - Oxford - Paris - Shannon - Tokyo
  5. 5. EJSEVIER SCIENCE LtdThe Boulevard, Langford LaneKidlington, Oxford OX5 IGB, UK0 2001 Yong BaiAll rights reserved. This work is ptuteckd under copyright of Yong Bai with assigned rights to Elsevier Science. The following terms andconditions apply to its use:PhotocopyingSingle photocopies of single chapters may be made for penonal use as allowed by national copyight laws. Permission of the Publisher andpayment of a fee is rcquired for all other photocopying, including multiple or systematic wpying. wpying for advertising or promotionalpurposes, resale, and all forms of document delivery. Speeial rates are available for educational institutions that wish to make photocopies fornon-profit educational classroom use.Permissions may be sought directly fmm Elsevier Science Global Rights Deparlmenl, PO Box 800. Oxford 0 5 IDX UK: phone: (+44) 1865 x843830, fax: (+44) 1865 853333, e-mail: permissions~lsevier.co.uk.You may also conlact Global Rights directly through Elsevier’s homc page(http://www.elsevier.nl), by selecting ‘Obtaining Permissions’.In the USA,users may elear permissions and make payments through tbe Copy?ight Clearance Cater, Inc.. 222 Rosewood Drive, Danveq MA01923, USA:phone: (+I ) (978) 7508400, fax: (+I) (978) 7504744, and in the UK through the Copyright LicensingAgency Rapid Clearance Service(CLARCS). 90Tottenham Court Road, London WIP OLP, U k phone: (+44) 207 631 5555: fax: (+44) 631 5500. Other countriesmay have a 207local reprographic rights agency for paymmts.Derivative WorksTables of contents may bc rrproduced for internal circulation, but permission of Elsevier Science is required for external resale or distribution ofsuch material.Permission of the Publisher is required for all other derivative works. including compilations and translations.Elccnonic Storage or UsagePermission of the Publisher is required to store or use elecironically any material contained in this work, including any chapter or part of achapter.Execpt as outlined above. no part of this work may be reproduced, stoled in a relricval syslem or VawniWd in any form or by any m a s en,electronic,mechanical. photocopying. rewrdding or otherwise. without prior Unitten permission of the Publisher.Address permissionsrequests to: Elsevier Global Rights Department, at the mail, fax and e-mail addresses noted above.NoticcNo mponsibility is assumed t the Publisher for any injury andlor damage to persons or propcrly 08 a mattcr of products liability, negligence or yotherwise, or from any use or operation of any mechods, products, instructions or ideas contained in the material herein. Because of rapidadvances in the medical sciences, in panicular, independent verification of diagnoses and drug dosass should be made.First edition 2001Second impression 2003Library of Congress Cataloging in Publication DataA catalog record from the Library of Congress has been applied for.British Library Cataloguing in Publication DataA catalogue record from the British Library has been applied for,ISBN 0 08 043712 5 (hardcover)8 The paper used in this publication meets the requirements of ANSUNIS0 239.48-1992 (Permanence ofPaper).Printed in The Netherlands.
  6. 6. VSERIES PREFACE In this day and age, humankind has come to the realization that theEarths resources are limited. In the 19h and 20thCenturies, these resourceshave been exploited to such an extent that their availability to futuregenerations is now in question. In an attempt to reverse this march towardsself-destruction, we have turned out attention to the oceans, realizing thatthese bodies of water are both sources for potable water, food and mineralsand are relied upon for World commerce. In order to help engineers moreknowledgeably and constructively exploit the oceans, the Elsevier OceanEngineeringBook Series has been created. The Elsevier Ocean Engineering Book Series gives experts invarious areas of ocean technology the opportunity to relate to others theirknowledge and expertise. In a continual process, we are assembling world-class technologists who have both the desire and the ability to write books.These individuals select the subjects for their books based on their educationalbackgrounds and professional experiences. The series differs from other ocean engineering book series in that thebooks are directed more towards technology than science, with a fewexceptions. Those exceptions we judge to have immediate applications tomany of the ocean technology fields. Our goal is to cover the broad areas ofnaval architecture, coastal engineering, ocean engineering acoustics, marinesystems engineering, applied oceanography, ocean energy conversion, designof offshore structures, reliability of ocean structures and systems and manyothers. The books are written so that readers entering the topic fields canacquire a working level of expertise from their readings. We hope that the books in the series are well-received by the oceanengineering community. Ramesw ar Bhattacharyya Michael E. McCorrnick Series Editors
  7. 7. viiFOREWORDThis new book provides the reader with a scope and depth of detail related to the design ofoffshore pipelines and risers, probably not seen before in a textbook format. With the benefitof nearly 20 years of experience, Professor Yong Bai has been able to assimilate the essenceof the applied mechanics aspects of offshore pipeline system design in a form of value tostudents and designers alike. The text is well supported by a considerable body of referencematerial to which Professor Yong Bai himself has made a substantial contribution over hiscareer. I have been in the field of pipeline engineering for the best part of 25 years and inthat time have seen the processes involved becoming better and better understood. This bookfurther adds to that understanding.Marine pipelines for the transportation of oil and gas have become a safe and reliable part ofthe expanding infrastructure put in place for the development of the valuable resources belowthe worlds seas and oceans. The design of these pipelines is a relatively young technologyand involves a relatively small body of specialist engineers and researchers worldwide. Inthe early 1980s when Professor Yong Bai began his career in pipelines, the technology wasvery different than it is today, being adapted from other branches of hydrodynamics,mechanical and marine engineering using code definitions and safety factors proven in otherapplications but not specific to the complex hydrodynamic-structure-seabed interactions seenin the behaviour of what is outwardly a simple tubular lying on or slightly below the seabed.Those designs worked then and many of the systems installed, including major oil and gastrunklines installed in the hostile waters of the North Sea, remain in safe service today. Whathas happened in the intervening period is that pipeline design processes have matured andhave been adapted and evolved to be fit for purpose for todays more cost effective pipelines;and will continue to evolve for future application in the inevitable move into deeper watersand more hostile environments.An aspect of the marine pipeline industry, rarely understood by those engineers working inland based design and construction, is the more critical need for a right first time approach inlight of the expense and complexity of the materials and the installation facilities involved,and the inability to simply go back and fix it after the fact when your pipeline is sitting inwater depths well beyond diver depth and only accessible by robotic systems. Money spenton good engineering up front is money well spent indeed and again a specific fit for purposemodem approach is central to the best in class engineering practice requisite for this rightfirst time philosophy. Professor Yong Bai has made important contributions to this comingof age of our industry and the benefit of his work and knowledge is available to those whoread and use this book.It is well recognised that the natural gas resources in the worlds ocean are gaining increasingimportance as an energy source to help fuel world economic growth in the established andemerging economies alike. Pipelines carry a special role in the development and productionof gas reserves since, at this point in time, they provide one of the most reliable means fortransportation given that fewer options are available than for the movement of hydrocarbonliquids. Add to this the growing need to provide major transportation infrastructure betweengas producing regions and countries wishing to import gas, and future oil transmissionsystems, then the requirement for new offshore pipelines appears to be set for several years tocome. Even today, plans for pipeline transportation infrastructure are in development forregions with more hostile environments and deeper waters than would have been thought
  8. 8. viiiachievable even ten years ago. The challenges are out there and the industry needs acontinuous influx of young pipeline engineers ready to meet those challenges. ProfessorYong Bai has given us, in this volume, an excellent source of up to date practices andknowledge to help equip those who wish to be part of the exciting future advances to come inour industry.Dr Phillip W J RavenGroup Managing DirectorJ P Kenny Group of Companies
  9. 9. ixPREFACEThis book is written for engineers who work on pipelines, risers and piping. It summarizes theauthor’s 18 years research and engineering experience at universities, classification societiesand design offices. It is intended to develop this book as a textbook for graduate students,design guidelines for engineers and references for researchers. It is hoped that this book mayalso be used for design of offshore structures as it mainly addresses applied mechanics anddesigdengineering.Starting from August 1998, the book has been used in a teaching course for MSc. students atStavanger University College and IBC training course for engineers in pipeline and riserindustries.The preparation of the book is motivated by recent developments in research and engineeringand new design codes. There is a need for such a book to educate more pipeline engineers andprovide materials for on-job training on the use of new design codes and guides.Thanks is given to my colleagues who have guided me into this field: Prof. Torgeir Moan atNorwegian University of Science and Technology; Prof. Robert Bea and Prof. A. Mansour atUniversity of California at Berkeley; Prof. Preben Temdrup Pedersen at Technical Universityof Denmark Prof. Tetsuya Yao at Hiroshima University; and Chief Engineer Per A. Damslethat J P Kenny A / S (Now part of ABB Offshore Systems AS). The friendship and technicaladvice from these great scientists and engineers have been very helpful to generate basis forthis book.As the Chief Engineer, Per Damsleth has given the author a lot of advice and supports duringlast years. Managing Director Jan-Erik Olssm and Engineering Manager Gawain Langford ofJ P Kenny AIS are acknowledged for a friendly and creative atmosphere. Dr. Ruxin Song andTerjer Clausen at Brown & Root Energy Services (Halliburton) are appreciated for theiradvice on risers and bundles. Jens Chr. Jensen and Mark S@rheim deeply appreciated for areediting assistance during preparation of the book. Senior Vice President Dr. Donald Liu atABS provided guidance and encouragement for the completion of this book.Special thanks to my wife, Hua Peng, daughter Lihua and son Carl for their love,understanding and support that have been very important for the author to continue manyyears of hard work and international traveling in different cultures, languages and workingenvironments.Professor Yong BaiStavanger University College, N-4091 Stavanger, NORWAYandAmerican Bureau of Shipping, Houston, TX 77060, USA
  10. 10. Contents XITABLE OF CONTENTSSeries Preface VForeword viiPreface ixChapter 1 Introduction 1 1.1 Introduction .............................................................................................................................................. 1 1.2 Design Stages and Process....................................................................................................................... 1 1.2.1 Design Stages................................................................................................................................... 1 1.2.2 Design Process................................................................................................................................. 4 1.3 Design Through Analysis (DTA)............................................................................................................. 7 I .4 Pipeline Design Analysis ......................................................................................................................... 9 1.4.1 General............................................................................................................................................. 9 1.4.2 Pipeline Stress Checks ..................................................................................................................... 9 1.4.3 Span Analysis................................................................................................................................. IO 1.4.4 On-bottom Stability Analysis......................................................................................................... 11 1.4.5 Expansion Analysis........................................................................................................................ 14 1.4.6 Buckling Analysis ....................................................................................... 14 I .4.7 Pipeline Installatio ................................................................................................ 17 1.5 Pipeline Simulator.................................................................................................................................. 19 1.6 References.................................................................................................................Chapter 2 Wall-thickness and Material Grade Selection 23 2.1 General................................................................................................................................................... 23 2.1. I General........................................................................................................................................... 23 2.1.2 Pipeline Design Codes ................................................................................................................... 23 2.2 Material Grade Selection........................................................................................................................ 24 2.2.1 General Principle............................................................................................................................ 24 2.2.2 Fabrication, Installationand Operating Cost Considerations......................................................... 25 2.2.3 Material Grade Optimization ......................................................................................................... 25 2.3 Pressure Containment(hoop stress) Design ........................................................................................... 26 2.3.1 General........................................................................................................................................... 26 2.3.2 Hoop Stress Criterion of DNV (2000) ........................................................................................... 27 2.3.3 Hoop Stress Criterion of ABS (2000) ............................................................................................ 28 2.3.4 API RPl 11 1 (1998) ........................................................................................................................ 2Y 2.4 Equivalent Stress Criterion ............................................................................................................... 2.5 Hydrostatic Collapse......................................................................................................................... 2.6 Wall Thickness and Length Design for Buckle Arrestors ...................................................................... 34 2.7 Buckle Arrestor Spacing Design ............................................................................................................ 35 2.8 References.............................................................................................................................................. 36Chapter 3 BucklinglCollapse of Deepwater Metallic Pipes 39 3.1 General....................................................................................................................... 3.2 Pipe Capacity under Single Load ........................................................................................................... 40 3.2.1 General........................................................................................................................................... 40 3.2.2 External Pressure............................................................................................................................ 41 3.2.3 Bending Moment Capacity............................................................................................................. 44 3.2.4 Pure Bending............. ............................................................................................................ 46 3.2.5 Pure Internal Pressure .................................................................................................................... 46 3.2.6 Pure Tension .................................................................................................................................. 46 3.2.7 Pure Compression . .................................................................................................................... 47
  11. 11. XI1 Contents 3.3 Pipe Capacity under Couple Load .......................................................................................................... 47 3.3.1 Combined Pressure and Axial Force.............................................................................................. 47 3.3.2 Combined External Pressure and Bending..................................................................................... 48 3.4 Pipes under Pressure Axial Force and Bending ..................................................................................... 49 3.4.1 Case 1 -Corroded Area in Compression....................................................................................... 49 3.4.2 The Location of the Fully Plastic Neutral Axis .............................................................................. 51 3.4.3 The Bending Moment .................................................................................................................... 51 3.5 Finite Element Model ............................................................................................................................. 55 3.5.1 General........................................................................................................................................... 55 3.5.2 Analytical Solution Versus Finite Element Results ....................................................................... 56 3.5.3 Capacity of Pipes Subjected to Single Loads ................................................................................. 56 3.5.4 Capacity of Pipes Subjected to Combined Loads........................................................................... 58 3.6 References.............................................................................................................................................. 61Chapter 4 Limit-state based Strength Design 63 4.1 Introduction............................................................................................................................................ 63 4.2 Out of Roundness ServiceabilityLimit .................................................................................................. 64 4.3 Bursting.................................................................................................................................................. 65 4.3.1 Hoop Stress vs . Equivalent Stress Criteria..................................................................................... 65 4.3.2 Bursting Strength Criteria for Pipeline........................................................................................... 65 4.4 Local Buckling/Collapse........................................................................................................................ 67 4.5 Fracture .................................................................................................................................................. 70 4.5.1 PD6493 Assessment....................................................................................................................... 70 4.5.2 Plastic Collapse Assessment.......................................................................................................... 72 4.6 Fatigue......................................................................................................... .................................... 73 4.6.1 General................................................................................................ .................................... 73 4.6.2 Fatigue Assessment based on S-N Curves ..................................................................................... 74 4.6.3 Fatigue Assessment based on A&-NCurves ................................................................................... 74 4.7 Ratcheting .............................................................................................................................................. 75 4.8 Dynamic Strength Criteria ..................................................................................................................... 75 4.9 Accumulated Plastic Strain .................................................................................................................... 75 4.10 Strain Concentration at Field Joints Due to Coatings ....................................... 4.1 1 References.............................................................................................................................................. 76Chapter 5 Soil and Pipe Interaction 79 5.1 General............................................................................................................. 5.2 Pipe Penetration in Soil .. ............................................................................................. 19 5.2.1 Verley and Lund Method ............................................................................................................... 79 5.2.2 Classical Method............................................................................................................................ 80 5.2.3 Buoyancy Method .......................................................................................................................... 81 5.3 Modeling Friction and Breakout Forces................................................................................................. 82 5.3. I Anisotropic Friction ....................................................................................................................... 82 5.3.2 Breakout Force............................................................................................................................... 82 5.4 References.............................................................................................................................................. 83Chapter 6 Hydrodynamics around Pipes 85 6.1 Wave Simulators.................................................................................................................................... 85 6.2 Choice of Wave Tkeory ......................................................................................................................... 85 6.3 Mathematical Formulations used in the Wave Simulators..................................................................... 85 6.3.1 General ........................................................................................................................................... 85 6.3.2 2D Regular Long-Crested Waves .................................................................................................. 86 6.3.3 2D Random Long-Crested Waves.................................................................................................. 87 6.4 Steady Currents ...................................................................................................................................... 90
  12. 12. Contents X1 I1 6.5 Hydrodynamic Forces ............................................................................................................................ 91 6.5.1 HydrodynamicD a and Inertia Forces ......................................................................................... rg 91 6.5.2 Hydrodynamic Lift Forces ............................................................................................................. 94 6.6 References.............................................................................................................................................. 95Chapter 7 Finite Element Analysis of In-situ Behavior 97 7.1 Introduction ............................................................................................................................................ 97 7.2 Description of the Finite Element Model ............................................................................................... 98 7.2.1 Static Analysis Problems................................................................................................................ 98 7.2.2 Dynamic Analysis Problems ............................................................... 7.3 Steps in an Analysis and Choice of Analysis Procedure ............................. ................................... 101 7.3.1 The Static Analysis Procedure ..................................................................................................... 101 7.3.2 The Dynamic Analysis Procedure ................................................................................................ 101 7.4 Element Types used in the Model ........................................................................................................ 102 7.5 Non-linearity and Seabed Model ......................................................................................................... 104 7.5.1 Material Model ............................................................................................................................. 104 7.5.2 Geometrical non-linearity ................................................. 7.5.3 Boundary Conditions ........................................................ 7.5.4 Seabed Model .................................................................... 7.6 Validation of the Finite-Element Model ................................... 7.7 References............................................................................................................................................ 106Chapter 8 On-bottom Stability I09 8.1 General ................................................................................................................................................. 109 8.2 Force Balance: The Simplified Method ............................................................................................... 110 8.3 Acceptance Criteria............................................................... .......................................................... 110 8.3.1 Allowable Lateral Displacement ................................................................................................. 110 8.3.2 Limit-state Strength Criteria.................. .................................................................................. 110 8.4 Special Purpose Program for Stability Analysis .................................................................................. 111 8.4. I General......................................................................................................................................... 111 8.4.2 PONDUS...................................................................................................................................... 111 8.4.3 PIPE ............................................................................................................................................. 113 8.5 Use of FE Analysis for I ntion Design............................. 8.5.1 Design Procedure .. ............................................................................................................. 114 8.5.2 Seabed Intervention............................................................................................ 8.5.3 Effect of Seabed Intervention ....................................................................................................... 115 8.6 References ................................................................................................................................Chapter 9 Vortex-induced Vibrations (WV)and Fatigue 117 9.I ...................................................................................................... 117 9.2 .......................................... 9.2.1 .......................................... 9.2.2 ....................................................... 9.2.3 Soil Stiffness Analysis .................................................................. 9.2.4 Vibration Amplitude and Stress Range Analysis ......................................................................... 124 ................................................................................................................ 124 .......................... 124 9.4.2 Cross-flow VIV in Combined Wave and Current ........................................................................ 128 9.5 Modal Analysis ................ ...................... .................. ......... .129 9.5.1 Introduction.................................................................................................................................. 129
  13. 13. XIV Contents 9.5.2 Single Span Modal Analysis........................................................................................................ 130 9.5.3 Multiple Span Modal Analysis..................................................................................................... 130 9.6 Example Cases ..................................................................................................................................... 131 9.6.1 General......................................................................................................................................... 131 9.6.2 Fatigue Assessment ...................................................................................................................... 133 9.7 References............................................................................................................................................ 135Chapter 10 Force Model and Wave Fatigue 137 10.1 Introduction.......................................................................................................................................... 137 10.2 Fatigue Analysis................................................................................................................................... 138 10.2.1 Fatigue of Free-spanning Pipelines.............................................................................................. 138 10.2.2 Fatigue Damage Assessment Procedure ...................................................................................... 140 10.2.3 Fatigue Damage Acceptance Criteria........................................................................................... 141 10.2.4 Fatigue Damage Calculated using Time-Domain Solution .......................................................... 142 10.2.5 Fatigue Damage Calculated Using Frequency Domain Solution ................................................. 142 10.3 Force Model ......................................................................................................................................... 144 10.3.1 The Equation of In-line Motion for a Single Span ....................................................................... 144 10.3.2 Modal Analysis ............................................................................................................................ 145 10.3.3 Time Domain Solution................................................................................................................. 147 10.3.4 Frequency Domain Solution......................................................................................................... 150 10.4 Comparisons of Frequency Domain and Time Domain Approaches................................................... 152 10.5 Conclusions and Recommendations..................................................................................................... 153 10.6 References............................................................................................................................................ 154Chapter 11 Trawl Impact, Pullover and Hooking Loads 155 11.1 Introduction.......................................................................................................................................... 155 1 1.2 Trawl Gears.............................................................................................. 1 1.2.1 Basic Types of Trawl Gear .......................................................................................................... 155 1 1.2.2 Largest T a l Gear in Present Use .............................................................................................. rw 156 11.3 Acceptance Criteria.............................................................................................................................. 156 11.3.1 Acceptance Criteria for Impact Response Analyses .................................................................... 156 11.3.2 Acceptance Criteria for Pullover Response Analyses .................................................................. 157 11.4 Impact Response Analysis ................................................................................................................... 157 11.4.1 General......................................................................................................................................... 157 11.4.2 Methodology for Impact Response Analysis ............................................................................... 157 11.4.3 Steel Pipe and Coating Stifmess .................................................................................................. 160 11.4.4 Trawl Board Stiffness, Mass and Hydrodynamic Added Mass.................................................... 163 11.4.5 Impact Response ............................................................................ 11.5 Pullover Loads ....................................................................................... 11.6 Finite Element Model for Pullover Response Analyses ....................................................................... 168 11.6.1 General......................................................................................................................................... 168 11.6.2 Finite Element Models ................................................................................................................. 168 11.6.3 Analysis Methodology ................................................................................................................. 169 1 1.7 Case Study ........................................................................................................................................... 170 11.7.1 General......................................................................................................................................... 170 11.7.2 Trawl Pull-Over For Pi on an Uneven Seabed .................................................................. 170 11.8 References........................... ..................................................................................................... 175Chapter 12 Installation Design 177 12.1 Introduction.......................................................................................................................................... 177 12.2 Pipeline InstallationVessels ................................................................................................................ 178 12.2.1 Pipelay Semi-submersibles.......................................................................................................... 178 12.2.2 Pipelay Ships and B ~.............................................................................................................. g 182
  14. 14. Contents xv 12.2.3 Pipelay Reel Ships ....................................................................................................................... 183 12.2.4 Tow or Pull Vessels ..................................................................................................................... 184 12.3 Software OFFPIPE and Code Requirements........................................................................................ 185 12.3.1 OFFPIPE............................................................................................................. 12.3.2 Code Requirements..................................................................................... 12.4 Physical Background for Installation .................................................................. 12.4.1 S-lay Method............................................................................................... 12.4.2 Static Configuration.................................................................................... 12.4.3 Curvature in Sagbend.................................................................................. 12.4.4 Hydrostatic Pressure.................................................................................... 12.4.5 Curvature in Overbend................................................................................................................. 192 12.4.6 S r i Concentration and Residual Strain .................................................................................... tan 193 12.4.7 Rigid Section in the Pipeline........................................................................................................ 193 12.4.8 Dry weightlsubmergedweight..................................................................................................... 194 12.4.9 Theoretical Aspects of Pipe Rotation.............................................................................. 12.4.10 Installation Behaviour of Pipe with Residual Curvature.......................................................... 201 12.5 Finite Element Analysis Procedure for Installation of In-line Valves.................................................. 204 12.5.1 Finding Static Configuration........................................................................................................ 204 12.5.2 Pipeline Sliding on Stinger.............................................................................................. .207 12.5.3 Installation of In-line Valve ......................................................................................................... 208 12.6 Two Medium Pipeline Design Concept ............................................................................................... 209 12.6.1 Introduction.................................................................................................................................. 209 12.6.2 Wall-thickness Design for Three Medium and Two Medium Pipelines ........... 12.6.3 Implication to Installation, Testing and Operation............................................ 12.6.4 Installing Free Flooding Pipelines................................................................................................ 211 12.6.5 S-Lay vs. J-Lay ......................... ....................................................... 12.6.6 Economic Implication......................................................... ....................................... 215 12.7 References................................................................................... ...........................Chapter 13 Reliability-Based Strength Design of Pipelines 219 13.1 General ................................................................................................................................................. 219 13.2 Reliability-based Design ...................................................................................................................... 220 13.2.1 General ......................................................................................................................................... 220 13.3.2 Classification of Uncertainties........ 13.3.4 Determination of Statistical Values.............................................................................................. 223 13.4 Calibration of Safety Factors ............................................................................................................... 223 13.4.1 General ......................................................................................................................................... 223 13.4.2 Target Reliability Levels.............................................................................................................. 224 13.5 BucklingKollapse of Corroded Pipes .................................................................................................. 224 13.5.1 Buckling/Collapse........................................................................................................................ 224 13.5.2 Analytical Capacity Equation....................................................................................................... 225 13.5.3 Design Format.............................................................................................................................. 225 13.5.4 Limit-State Function ................. ............................................................. .225 13.5.5 Calibration of Safety Factors..... ........................................................................................... 226 13.6 Conclusions.......................................................................................................................................... 227 13.7 References ............. .227
  15. 15. XVI ContentsChapter 14 Remaining Strength of Corroded Pipes 229 14.1 Introduction.......................................................................................................................................... 229 14.2 Review of Existing Criteria.................................................................................................................. 230 14.2.1 NG-18 Criterion........................................................................................................................... 230 14.2.2 B3 1G Criterion ............................................................................................................................. 231 14.2.3 Evaluation of Existing Criteria ..................................................................................................... 232 14.2.4 Corrosion Mechanism .................................................................................................................. 232 14.2.5 Material Parameters ..................................................................................................................... 235 14.2.6 Problems excluded in the B3 1G Criteria...................................................................................... 236 14.3 Development of New Criteria .............................................................................................................. 237 14.4 Evaluation ofNew Criteria .................................................................................................................. 240 14.5 Reliability-based Design ...................................................................................................................... 240 14.5.1 T r e Failure Probability ............................................................................................................ agt 241 14.5.2 Design Equation and Limit State Function .................................................................................. 241 14.5.3 Uncertainty................................................................................................................................... 243 14.5.4 Safety Level in the B31G Criteria................................................................................................ 245 14.5.5 Reliability-based Calibration........................................................................................................ 245 14.6 Example Applications .......................................................................................................................... 246 14.6.1 Condition Assessment .................................................................................................................. 249 14.6.2 Rehabilitation............................................................................................................................... 254 14.7 Conclusions.......................................................................................................................................... 254 14.8 References............................................................................................................................................ 254Chapter 15 Residual Strength of Dented Pipes with Cracks 257 15.1 Introduction.......................................................................................................................................... 257 15.2 Fracture of Pipes with Longitudinal Cracks......................................................................................... 258 15.2.1 Failure Pressure of Pipes with Longitudinal Cracks .................................................................... 258 15.2.2 Burst Pressure of Pipes ContainingCombined Dent and Longitudinal Notch ............................. 259 15.2.3 Burst Strength Criteria ................................................................................................................. 261 15.2.4 Comparisons with Test................................................................................................................. 261 15.3 Fracture of Pipes with CircumferentialCracks .................................................................................... 262 15.3.1 Fracture Condition and Critical Stress ......................................................................................... 262 15.3.2 Material Toughness, K, ............................................................................................................. 263 15.3.3 Net Section Stress, Q ................................................................................................................... 263 15.3.4 Maximum Allowable Axial Stress ............................................................................................... 263 15.4 Reliability-basedAssessment and Calibration of Safety Factors ......................................................... 263 15.4.1 Design Formats vs . LSF ............................................................................................................... 264 15.4.2 Uncertainty Measure .................................................................................................................... 265 15.4.3 Reliability Analysis Methods ....................................................................................................... 266 15.4.4 Target Safety Level ...................................................................................................................... 267 15.4.5 Calibration.................................................................................................................................... 267 15.5 Design Examples.................................................................................................................................. 267 15.5.1 Case Description .......................................................................................................................... 267 15.5.2 Parameter Measurements ............................................................................................................. 268 15.5.3 Reliability Assessments ............................................................................................................... 268 15.5.4 Sensitivity Study .......................................................................................................................... 272 15.5.5 Calibration of Safety Factor ......................................................................................................... 273 15.6 Conclusions.......................................................................................................................................... 274 15.7 References ............................................................................................................................................ 274Chapter 16 Risk Analysis applied to Subsea Pipeline Engineering 277 16.1 Introduction .......................................................................................................................................... 277 16.1.1 General ...................................... ...................................................................................... 277
  16. 16. Contents XVlI 16.1.2 Risk Analysis Objectives......................................................................................................... 277 16.1.3 Risk Analysis Concepts........................................................................................................... 278 16.2 Acceptance Criteria.............................................................................................................................. 279 16.2.1 General ............................................................................................................................. 16.2.2 Individual Risk ........................................................................................................................ 280 16.2.3 Societal Risk ............................................................................................................................ 280 16.2.4 Environmental Risk................................................................................................................. 281 16.2.5 Financial Risks ........................................................................................................................ 282 16.3 Identificationof Initiating Events ........................................................................................................ 283 16.4 Cause Analysis..................................................................................................................................... 283 16.4.1 General .............................................................................................................. 16.4.2 Fault Tree Analysis ................................................................................................................. 284 16.4.3 Event Tree Analysis ................................................................................................................ 284 Events ............................................................................................................ 284 ....................................................................................................................... 284 ....................................................................................................................... 285 16.6 Causes of Risks .................................................................................................................................... 287 16.6.1 General .................................................................................................................................... 287 16.6.2 1" Party Individual Risk .......................................................................................................... 287 16.6.3 Societal, Environmental and Material Loss Risk .................................................................... 288 16.7 ConsequenceAnalysis ......................................................................................................................... 288 16.7.1 Consequence Modeling........................................................................................................... 288 16.7.2 1*P r y Individual and Societal Risk ...................................................................................... at 291 16.7.3 Environmental Risks ............................................................................................................... 291 16.7.4 Material Loss Risk................................................................................................................... 291 16.8 Example 1: Risk analysis for a Subsea Gas Pipeline ........................................................................... 292 I 6.8.1 General .................................................................................................................................... 292 16.8.2 Gas Releases ............................................................................................................................ 292 16.8.3 Individual Risk ........................................................................................................................ 294 16.8.4 Societal Risk ............................................................................................................................ 295 16.8.5 Environmental Risk ................................................................................................................. 297 16.8.6 Risk of Material Loss .............................................................................................................. 297 16.8.7 Risk Estimation ....................................................................................................................... 298 16.9 Example 2: Dropped Object Risk Analysis .......................................................................................... 298 16.9.1 General .................................................................................................................................... 298 16.9.2 Acceptable Risk Levels .............................................................................. 16.9.3 Quantitative Cause Analysis....................................................................... 16.9.4 Results ........................................................................... ................................... 301 16.9.5 ConsequenceAnalysis................................................... .................................................. 302 16.10 References......................... ................................................................................................. 303Chapter 17 Route Optimization, Tie-in and Protection 305 17.1 Introduction .......................................................................................................................................... 305 17.2 Pipeline Routing....................................................................................... .................................... 305 17.2.1 General Principle.............................................................................. .................................... 305 17.2.2 Fabrication. Installation and OperationalCost Considerations ........................................ 17.2.3 Route Optimization.......................................................................................................... 17.3 Pipeline Tie-ins ................................................ ........................................................................... 307 17.3.1 Spoolpieces.................................................................................................................................. 307 17.3.2 Lateral Pull ................................................................................................................................... 309 17.3.3 J-Tube Pull-In .............................................................................................................................. 310 17.3.4 Connect and Lay Away ..................................................................................................... 17.3.5 Stalk-on ........................................................................................................................................ 315 17.4 Flowline TrenchinglBurying. .......................................................................... 315 17.4.1 Jet Sled ......................................................................................................................................... 315 17.4.2 Ploughing............ ................................................................................................................... 317
  17. 17. XVIII Contents 17.4.3 Mechanical Cutters....................................................................................................................... 319 17.5 Flowline Rockdumping........................................................................................................................ 319 17.5.1 Side Dumping .............................................................................................................................. 322 17.5.2 Fall Pipe ....................................................................................................................................... 322 17.5.3 Bottom Dropping ......................................................................................................................... 322 17.6 Equipment Dayrates............................................................................................................................. 323 17.7 References............................................................................................................................................ 323Chapter IS Pipeline Inspection, Maintenance and Repair 325 18.1 Operations............................................................................................................................................ 325 18.1.1 Operating Philosophy.......... .................................................................................................... 325 18.1.2 Pipeline Security .......................................................................................................................... 325 18.1.3 Operational Pigging ..................................................................................................................... 327 18.1.4 Pipeline Shutdown ....................................................................................................................... 329 18.1.5 Pipeline Depressurization............................................................................................................. 330 18.2 Inspection by Intelligent Pigging ......................................................................................................... 330 18.2.1 General......................................................................................................................................... 330 18.2.2 Metal Loss Inspection Techniques............................................................................................... 331 18.2.3 Intelligent Pigs for Purposes other than Metal Loss Detection.................................................... 338 18.3 Maintenance......................................................................................................................................... 340 18.3.1 General......................................................................................................................................... 340 18.3.2 Pipeline Valves ............................................................................................................................ 341 18.3.3 Pig Traps ...................................................................................................................................... 341 18.3.4 Pipeline Location Markers ........................................................................................................... 341 18.4 Pipeline Repair Methods...................................................................................................................... 342 18.4.1 Conventional Repair Methods...................................................................................................... 342 18.4.2 General Maintenance Repair........................................................................................................ 343 18.5 Deepwater Pipeline Repair................................................................................................................... 350 18.5.1 General......................................................................................................................................... 350 18.5.2 Diverless Repair- Research and Development............................................................................. 350 18.5.3 Deepwater Pipeline Repair Philosophy........................................................................................ 351 18.6 References............................................................................................................................................ 352Chapter 19 Use of High Strength Steel 353 19.1 Review of Usage of High Strength Steel Linepipes............................................................................. 353 19.1.1 Usage ofX7O Linepipe ................................................................................................................ 353 19.1.2 Usage ofX80 Linepipe ................................................................................................................ 357 19.1.3 Grades Above X80 ....................................................................................................................... 362 19.2 Potential Benefits and Disadvantagesof High Strength Steel.............................................................. 367 19.2.1 Potential Benefits of High Strength Steels ................................................................................... 367 19.2.2 Potential Disadvantages of High Strength Steels......................................................................... 369 19.3 Welding of High Strength Linepipe..................................................................................................... 371 19.3.1 Applicability of Standard Welding Techniques........................................................................... 371 19.3.2 Field Welding Project Experience ............................................................................................... 373 19.4 Cathodic Protection.............................................................................................................................. 374 19.5 Fatigue and Fracture of High Strength Steel ........................................................................................ 375 19.6 Material Property Requirements .......................................................................................................... 376 19.6.1 General......................................................................................................................................... 376 19.6.2 Material Property Requirement in CircumferentialDirection...................................................... 376 19.6.3 Material Property Requirement in Longitudinal Direction .......................................................... 377 19.6.4 Comparisons of Material Properly Requirements........................................................................ 377 19.7 References............................................................................................................................................ 379
  18. 18. Contents XIXChapter 20 Design of Deepwater Risers 38 1 20.1 General................................................................................................................................................. 381 20.2 Descriptions of Riser System ............................................................................................................... 381 20.2.1 General......................................................................................................................................... 381 20.2.2 System Descriptions..................................................................................................................... 384 20.2.3 Component Descriptions .............................................................................................................. 384 20.2.4 Catenary and Top Tensioned Risers............................................................................................. 385 20.3 Metallic Catenary Riser for Deepwater Environments ........................................................................ 386 20.3.1 General......................................................................................................................................... 386 20.3.2 Design Codes ............................................................................................................................... 387 20.3.3 Analysis Parameters ..................................................................................................................... 387 20.3.4 Installation Studies...................... ............................................................................................ 388 20.3.5 Soil-Riser Interaction .................. ............................................................................................ 388 20.3.6 TDP Response Prediction ............................................................................................................ 389 20.3.7 Pipe Buckling Collapse under Extreme Conditions .................................................... 20.3.8 Vortex Induced Vibration Analysis............................................................................. 20.4 Stresses and Service Life of Flexible Pipes ......................................................................... 20.5 Drilling and Workover Risers .............................................................................................................. 391 20.6 Riser Projects in Norway ..................................................................................................................... 391 20.7 References............................................................................................................................................ 392Chapter 21 Design Codes and Criteria for Risers 393 2 1.1 Design Guidelines for Marine Riser Design ............................................................................ 21.2 Design Criteria for Deepwater Metallic Risers .................................................................................... 395 21.2.1 Design Philosophy and Considerations ......................................... ................................ 395 21.2.2 Currently Used Design Criteria.................................................................................................... 396 21.2.3 Ultimate Limit State Design Checks .............. ..... ................................ 397 21.3 Limit State Design Criteria .................................................................................................................. 397 21.3.1 General......................................................................................................................................... 397 21.3.2 Failure Modes and Limit States ................................................................................................... 397 21.3.3 Safety Classes ............................................................................................... 398 21.3.4 Design Procedure......................................................................................................................... 39Y 2 I .3.5 Acceptance Criteria...................................................................................................................... 399 21.3.6 LRFD Design Formats ................................................................................................................. 399 21.3.7 Local Strength Design through Analysis...................................................................................... 399 2 I .4 Design Conditions and Loads .............................................................................................................. 399 21.4.1 General......................................................................................................................................... 399 21.4.2 Design Conditions........................................................................................................................ 399 21.4.3 Loads and Load Effects................................................................................................................ 401 21.4.4 Definition of Iaad Cases ............................................................................................................. 402 21.4.5 Load Factors....................................................................................................................... 21.5 lmproving Design Codes and Guidelines................................................................................... 21.5.1 General............................................................................................................................... 21.5.2 Flexible Pipes...................................................................... .................................. 404 21.5.3 Metallic Riser...................................................................... ................................................. 406 21.6 Comparison of IS0 and API Codes with Hauch and Bai (1999) ......................................................... 406 21.6.1 Riser Capacity under Combined Axial Force, Bending and Pressure .......................................... 406 21.6.2 Design Approaches ...................................................................................................................... 407 21.6.3 Application of codes .................................................................................................... .....407 2 1.7 References ............................................................................................................................................ 411Chapter 22 Fatigue of Risers 413 22.1 General ................................................................................................................................................. 413 22.2 Fatigue Causes ..................................................................................................................................... 413

×