《船舶与海洋工程结构风险评估》课程教学资源（书籍文献）Offshore Risk Assessment，Principles, Modelling and Applications of QRA Studies，Jan Erik Vinnem，2nd Edition

Springer Series in Reliability Engineering Jan Erik Vinnem Offshore Risk Assessment Principles,Modelling and Applications of QRA Studies 2nd Edition

Series EditorProfessorHoang PhamDepartment ofIndustrial EngineeringRutgersThe State University of New Jersey96 Frelinghuysen RoadPiscataway, NJ 08854-8018USAOthertitles inthis seriesThe Universal GeneratingFunction in Reliability Analysis and OptimizationGregory LevitinWarrantyManagementandProductManufactureD.N.P Murthy and Wallace R. BlischkeMaintenanceTheoryof ReliabilityToshio NakagawaSystem SoftwareReliabilityHoang PhamReliabilityandOptimal MaintenanceHongzhouWangand HoangPhamAppliedReliabilityandQualityB.S. DhillonShock and Damage Models in Reliability TheoryToshioNakagawaRisk ManagementTerje Aven and Jan Erik VinnemSatisfyingSafetyGoalsbyProbabilisticRiskAssessmentHiromitsu Kumamoto

Series Editor Professor Hoang Pham Department of Industrial Engineering Rutgers The State University of New Jersey 96 Frelinghuysen Road Piscataway, NJ 08854-8018 USA Other titles in this series The Universal Generating Function in Reliability Analysis and Optimization Gregory Levitin Warranty Management and Product Manufacture D.N.P Murthy and Wallace R. Blischke Maintenance Theory of Reliability Toshio Nakagawa System Software Reliability Hoang Pham Reliability and Optimal Maintenance Hongzhou Wang and Hoang Pham Applied Reliability and Quality B.S. Dhillon Shock and Damage Models in Reliability Theory Toshio Nakagawa Risk Management Terje Aven and Jan Erik Vinnem Satisfying Safety Goals by Probabilistic Risk Assessment Hiromitsu Kumamoto

PrefacetolstEditionFrom amodest start in Norway as a researchtool in the late1970s,Quantified RiskAssessment (QRA)for offshore installations has become a key issue in themanagement of Safety,Health and Environment in the oil and gas industriesthroughout the entire North Sea. While the initiatives in the early stages often camefromtheauthorities,theuseisnowmainlydrivenbytheindustryitself.TheQRAis seen as a vehicle to gain extended flexibility with respect to achievement of anacceptable safety standardin offshoreoperations.Themodelsmaybeweak insomeareas and theknowledge is sometimes limited,butstudiesareneverthelessused effectively in the search for concept improvement and optimisation of designandoperation.This book results from working with offshore QRAs for more than 20 years.The author has, during this period, had the opportunity to practice and evaluate theuse of such studies from different perspectives,the consultancy's, the operatingcompany's, the researcher's and the educator's point of view.The author has for several years taught a course in risk analysis of marinestructures at theFaculty of Marine Technology,NTNU, Trondheim, Norway.ThestartingpointforthemanuscripwastheneedtoupdatethelecturenotesItishopedthatthisbookinthefuturealsomaybeausefulreferencesourceforawider audience.Therehas beeyearsarapidexpansionoftheuseofforsomerisk assessments for the offshore oil and gas activities.It is expected that theexpansion is going to continue for some time, as the offshore petroleum industryexpands into new regions and meets newchallenges in old regions.The oil pricereached its lowest level for manyyears,during the first quarter of1999.Onemightbetemptedtothinkthatthe economic climatemayprohibitfurther attention to risk assessment and safety improvement.The oppositeisprobably more correct. As a friend in Statoil expressed not so long ago:"Wheneverthemarginsaregettingtighter,theneedforrisk assessments increases,asnewandmore optimised solutions are sought, each needing an assessment ofrisk'InNorway,thebeginningof1999 is alsothetimewhen theNorwegianPetrole-um Directorate is preparing a major revision of the regulations for offshoreinstallations and operations,anticipated to comeintoeffect in2001.Ithas obvious-lynotbeenpossibletocapturethefinalrequirementsofthenewregulations,butan

Preface to 1st Edition From a modest start in Norway as a research tool in the late 1970s, Quantified Risk Assessment (QRA) for offshore installations has become a key issue in the management of Safety, Health and Environment in the oil and gas industries throughout the entire North Sea. While the initiatives in the early stages often came from the authorities, the use is now mainly driven by the industry itself. The QRA is seen as a vehicle to gain extended flexibility with respect to achievement of an acceptable safety standard in offshore operations. The models may be weak in some areas and the knowledge is sometimes limited, but studies are nevertheless used effectively in the search for concept improvement and optimisation of design and operation. This book results from working with offshore QRAs for more than 20 years. The author has, during this period, had the opportunity to practice and evaluate the use of such studies from different perspectives; the consultancy’s, the operating company’s, the researcher’s and the educator’s point of view. The author has for several years taught a course in risk analysis of marine structures at the Faculty of Marine Technology, NTNU, Trondheim, Norway. The starting point for the manuscript was the need to update the lecture notes. It is hoped that this book in the future also may be a useful reference source for a wider audience. There has been for some years a rapid expansion of the use of risk assessments for the offshore oil and gas activities. It is expected that the expansion is going to continue for some time, as the offshore petroleum industry expands into new regions and meets new challenges in old regions. The oil price reached its lowest level for many years, during the first quarter of 1999. One might be tempted to think that the economic climate may prohibit further attention to risk assessment and safety improvement. The opposite is probably more correct. As a friend in Statoil expressed not so long ago: ‘Whenever the margins are getting tighter, the need for risk assessments increases, as new and more optimised solutions are sought, each needing an assessment of risk’. In Norway, the beginning of 1999 is also the time when the Norwegian Petrole￾um Directorate is preparing a major revision of the regulations for offshore installations and operations, anticipated to come into effect in 2001. It has obvious￾ly not been possible to capture the final requirements of the new regulations, but an

viPrefaceattempthas been madeto capturethenewtrends intheregulations,totheextentthey areknown.There have over the last 10-15 years been published a few textbooks on riskassessment,most of them are devoted to relatively generic topics.Some are alsofocused ontheriskmanagementaspects,ingeneral and withoffshoreapplicability.None areknown to address the needs and topics of the use of QRA studies by theoffshore industry in particular.The present work is trying to bridge this gap.The use of QRA studies is somewhat special in Northern Europe,and parti-cularly in Norway.The use of these techniques is dominated by offshore applica-tions, with the main emphasis on quantification of risk to personnel.Furthermore,therisk to personnel is virtually never concerned with exposure of the public tohazards.Thus,thestudiesarerarelychallengedfromamethodologypointofviewMostpeoplewill probably seethis as anadvantage,but it alsohas somedraw-backs.Suchchallengesmaynamelyalsoleadto improvements inthemethodology.Itmaynotbe quite coincidental that the interest in modelling improvementand development sometimes has been rather low between the risk analysts workingwith North Sea applications.This book attempts to describe the state-of-the-art with respect to modelling inQRA studies for offshore installations andoperations.It also identifies some of theweaknessesand areaswherefurtherdevelopment shouldbemade.Ihopethatfurther improvement may be inspired through these descriptions.0.1About the ContentsAQuantified RiskAssessmentof an offshore installationhas thefollowingmainsteps:1.Hazard identification2.Cause and probability analysis3.Accidental scenarios analysis4.Consequence,damageandimpairmentanalysis5.Escape,evacuationandrescueanalysis6.Fatalityrisk assessment7.AnalysisofriskreducingmeasuresThis book is structured in much the same way.There is at least one chapter(sometimesmore)devotedtoeach of thedifferent steps,inmainlythe sameorderas mentioned above. Quite a few additional chapters are included in the text, onrisk analysis methodology,analytical approaches for escalation, escape,evacuationandrescueanalysisofsafetyandemergencysystems,aswellasriskcontrolIt isimportant tolearnfrompast experience,particularly from previousaccidents.A dozen major accidents, mainly from the North Sea, arediscussed attheendof Chapter4,in ordertodemonstratewhatproblemsthathavebeenexperienced in the past

vi Preface attempt has been made to capture the new trends in the regulations, to the extent they are known. There have over the last 10-15 years been published a few textbooks on risk assessment, most of them are devoted to relatively generic topics. Some are also focused on the risk management aspects, in general and with offshore applicability. None are known to address the needs and topics of the use of QRA studies by the offshore industry in particular. The present work is trying to bridge this gap. The use of QRA studies is somewhat special in Northern Europe, and parti￾cularly in Norway. The use of these techniques is dominated by offshore applica￾tions, with the main emphasis on quantification of risk to personnel. Furthermore, the risk to personnel is virtually never concerned with exposure of the public to hazards. Thus, the studies are rarely challenged from a methodology point of view. Most people will probably see this as an advantage, but it also has some draw￾backs. Such challenges may namely also lead to improvements in the methodo￾logy. It may not be quite coincidental that the interest in modelling improvement and development sometimes has been rather low between the risk analysts working with North Sea applications. This book attempts to describe the state-of-the-art with respect to modelling in QRA studies for offshore installations and operations. It also identifies some of the weaknesses and areas where further development should be made. I hope that further improvement may be inspired through these descriptions. 0.1 About the Contents A Quantified Risk Assessment of an offshore installation has the following main steps: 1. Hazard identification 2. Cause and probability analysis 3. Accidental scenarios analysis 4. Consequence, damage and impairment analysis 5. Escape, evacuation and rescue analysis 6. Fatality risk assessment 7. Analysis of risk reducing measures This book is structured in much the same way. There is at least one chapter (sometimes more) devoted to each of the different steps, in mainly the same order as mentioned above. Quite a few additional chapters are included in the text, on risk analysis methodology, analytical approaches for escalation, escape, evacuation and rescue analysis of safety and emergency systems, as well as risk control. It is important to learn from past experience, particularly from previous accidents. A dozen major accidents, mainly from the North Sea, are discussed at the end of Chapter 4, in order to demonstrate what problems that have been experienced in the past

PrefaceviiThemainhazardstooffshorestructures arefireexplosion,collisionandfallingobjects.Thesehazards andtheanalysis of them arediscussed in separatechapters.Riskmitigationand control arediscussed intwo chapters,followedbyanoutlineof an alternative approach to risk modelling,speciallyfocused on risk relatingtoshort duration activities. Applications to shipping are finally discussed, mainlyrelatingtoproductionandstoragetankers,butalsowithaviewtoapplicationstoshipping ingeneral.0.2AcknowledgementsParts of the material used in developing these chapters were initiallyprepared for acourse conductedforPETRAD(ProgramforPetroleum ManagementandAdmini-stration),Stavanger,Norway.ManythankstoPETRADforallowingthematerialtobeusedinothercontexts.Some of the studies that have formed the main input to the statistical overviewsectionswerefinancedby Statoil, NorskHydro,SagaPetroleum,EifPetroleumNorge and the Norwegian Petroleum Directorate.The author is grateful that thesecompanies have allowed these studies tobe made publically available.Direct financial support was received from Faculty of Marine Technology,NTNU,this is gratefullyacknowledged.My part time position as Professor atFaculty of Marine Technology,NTNU, has also given the opportunity to devotetime to prepare lecture notes and illustrations over several years.The consultancywork in Preventor Ashas nevertheless financed the majority of the work, inclu-ding the external services.Thanks arealso expressedtoKluwer AcademicPublishers,Dordrecht,TheNetherlands,for agreeing to publish this book,and for providing inspiring andvaluableadvicethroughouttheprocess.Appendix A presents an overview of some of the important softwaretools thatarecommonlyused.Thanksto all theconsultancies and software supplierswhohaveprovidedtheinformationrequiredforthisappendix.AppendixBisadirectcopyof the normativetext in theNORSOKGuidelineforRisk and EmergencyPreparedness analysis,reproduced with kind permission from the NORSOKsecretariat.Some of the consultancies have kindly given permission to use some of theirmaterial, theirkind assistance is hereby beinggratefully acknowledged.DNV shallbethankedforallowingtheirdatabaseWorldwideOffshoreAccidentDatabank(WOAD)to beused free of charge,as input to the statistics in the book.TheFireResearch Laboratory at SINTEF has given kind permission to use illustrationsfromtheir fireon sea research,and Scandpowerhas grantedpermission touseanillustration of the risk assessment methodology.SafetecNordic has givenkindpermissiontouseresults andillustrationsfromtheirsoftwareCollide.Iam particularlyindebted to several personswhohave offered veryvaluablehelp in turning this into a final manuscript.My colleague Dr.David Bayly,CrandonConsultants,has reviewed therawmanuscriptand contributed with manyvaluable comments of botha technical and linguistic nature.The importance ofprovidingclearand concisetextcanneverbeoverestimated,theeffortsmadein

Preface vii The main hazards to offshore structures are fire, explosion, collision and falling objects. These hazards and the analysis of them are discussed in separate chapters. Risk mitigation and control are discussed in two chapters, followed by an outline of an alternative approach to risk modelling, specially focused on risk relating to short duration activities. Applications to shipping are finally discussed, mainly relating to production and storage tankers, but also with a view to applications to shipping in general. 0.2 Acknowledgements Parts of the material used in developing these chapters were initially prepared for a course conducted for PETRAD (Program for Petroleum Management and Admini￾stration), Stavanger, Norway. Many thanks to PETRAD for allowing the material to be used in other contexts. Some of the studies that have formed the main input to the statistical overview sections were financed by Statoil, Norsk Hydro, Saga Petroleum, Elf Petroleum Norge and the Norwegian Petroleum Directorate. The author is grateful that these companies have allowed these studies to be made publically available. Direct financial support was received from Faculty of Marine Technology, NTNU, this is gratefully acknowledged. My part time position as Professor at Faculty of Marine Technology, NTNU, has also given the opportunity to devote time to prepare lecture notes and illustrations over several years. The consultancy work in Preventor AS has nevertheless financed the majority of the work, inclu￾ding the external services. Thanks are also expressed to Kluwer Academic Publishers, Dordrecht, The Netherlands, for agreeing to publish this book, and for providing inspiring and valuable advice throughout the process. Appendix A presents an overview of some of the important software tools that are commonly used. Thanks to all the consultancies and software suppliers who have provided the information required for this appendix. Appendix B is a direct copy of the normative text in the NORSOK Guideline for Risk and Emergency Preparedness analysis, reproduced with kind permission from the NORSOK secretariat. Some of the consultancies have kindly given permission to use some of their material, their kind assistance is hereby being gratefully acknowledged. DNV shall be thanked for allowing their database Worldwide Offshore Accident Databank (WOAD) to be used free of charge, as input to the statistics in the book. The Fire Research Laboratory at SINTEF has given kind permission to use illustrations from their fire on sea research, and Scandpower has granted permission to use an illustration of the risk assessment methodology. Safetec Nordic has given kind permission to use results and illustrations from their software Collide. I am particularly indebted to several persons who have offered very valuable help in turning this into a final manuscript. My colleague Dr. David Bayly, Crandon Consultants, has reviewed the raw manuscript and contributed with many valuable comments of both a technical and linguistic nature. The importance of providing clear and concise text can never be overestimated, the efforts made in

viiPrefacethis regard are therefore of utmost importance. This unique contribution hascombined extensive linguistic improvements with pointed comments andadditional thoughts on the technical subjects. I am very grateful to you, David, foryour extensiveefforts directed at improvementof the rawmanuscript.Myoldest son, John Erling, hashelped me with several of the case studies thatare used in the text, plus quite a few of the illustrations. My part time secretary,Mrs Annbjorg Krogedal, has had to devote a lot effort to decipher a challenginghandwriting,thankyoufor enthusiasmnandpatience.Assistancewiththeproof-1reading has been provided by Ms Kjersti G. Petersen, thanks also to Kjersti forenthusiastic and valuable assistance.Finally,M.Sc.Haibo Chen has also helpedwiththeproofreadingandchecking of consistencyinthetext,yourkind assistanceisgratefullyacknowledgedBryne, May 1999Jan Erik Vinnem

viii Preface this regard are therefore of utmost importance. This unique contribution has combined extensive linguistic improvements with pointed comments and additional thoughts on the technical subjects. I am very grateful to you, David, for your extensive efforts directed at improvement of the raw manuscript. My oldest son, John Erling, has helped me with several of the case studies that are used in the text, plus quite a few of the illustrations. My part time secretary, Mrs Annbjørg Krogedal, has had to devote a lot effort to decipher a challenging handwriting, thank you for enthusiasm and patience. Assistance with the proof￾reading has been provided by Ms Kjersti G. Petersen, thanks also to Kjersti for enthusiastic and valuable assistance. Finally, M.Sc. Haibo Chen has also helped with the proof reading and checking of consistency in the text, your kind assistance is gratefully acknowledged. Bryne, May 1999 Jan Erik Vinnem

Prefaceto2ndEditionThis is the second edition of the book; the first edition was published in 1999.Theauthor has since then taken up a full professorship at University of Stavanger,Norway,teaching courses in offshorerisk analysis and management.This promp-tedaneedforan update of thebook.Thefact that several important developmentshave occurred since1999also implied that a major revision was required.Theoil pricehas reached itspeak in2006, at the highest level ever (nominally)But theeconomicclimate is at the sametime suchthat everyeffort ismadetoscrutinise how costs may be curtailed and profitmaximised. This will in manycircumstances call for careful consideration of risks, not just anoff the shelf riskanalysis',but a carefully planned and broad-ranging assessment of options andpossibilities to reduce risk.Norwegian offshore regulations were profoundly revised around the beginningofthenewcentury,withnewregulationbecominglawfrom2002.Thissecondedition of thebook captures some of theexperience and challenges fromthefirst 4-5 years of application of the new regulations.The important aspects of the newregulations are also briefly discussed, see Chapter 1.The first Norwegian White Paper on HES management in the offshore industrywas published in 2001, and the second in 2006. One of the needs identified in thispaper was the need to performmore extensiveR&Dwork in this field, and asignificantprogrammehasbeen runningngintheperiod2002-06.Someofthenewresults included in the second edition of thebookresult fromthat R&D initiative.About20 major accidents, mainly from theNorth Sea, arediscussed at somelength inChapter4,in ordertodemonstrate what problems havebeen experiencedin the past. I haveput more emphasis on this subject in the second edition, becauseit is essential that alsonewgenerationsmay learn from whatoccurred in thepast.Where available,observations about barrierperformance arediscussed in additiontothesequenceofeventsandlessonslearnedWhen itcomestomanagementofrisk anddecision-makingbased uponresultsfrom risk analyses, this is discussed separately in a book published in parallel withmy colleagueat University of Stavanger,Professor TerjeAven,alsopublishedbySpringer in 2007.Interested readers are referred to this work,‘Risk Management,withApplicationsfromtheOffshorePetroleumIndustry

Preface to 2nd Edition This is the second edition of the book; the first edition was published in 1999. The author has since then taken up a full professorship at University of Stavanger, Norway, teaching courses in offshore risk analysis and management. This promp￾ted a need for an update of the book. The fact that several important developments have occurred since 1999 also implied that a major revision was required. The oil price has reached its peak in 2006, at the highest level ever (nominally). But the economic climate is at the same time such that every effort is made to scrutinise how costs may be curtailed and profit maximised. This will in many circumstances call for careful consideration of risks, not just an ‘off the shelf risk analysis’, but a carefully planned and broad-ranging assessment of options and possibilities to reduce risk. Norwegian offshore regulations were profoundly revised around the beginning of the new century, with new regulation becoming law from 2002. This second edition of the book captures some of the experience and challenges from the first 4- 5 years of application of the new regulations. The important aspects of the new regulations are also briefly discussed, see Chapter 1. The first Norwegian White Paper on HES management in the offshore industry was published in 2001, and the second in 2006. One of the needs identified in this paper was the need to perform more extensive R&D work in this field, and a significant programme has been running in the period 2002–06. Some of the new results included in the second edition of the book result from that R&D initiative. About 20 major accidents, mainly from the North Sea, are discussed at some length in Chapter 4, in order to demonstrate what problems have been experienced in the past. I have put more emphasis on this subject in the second edition, because it is essential that also new generations may learn from what occurred in the past. Where available, observations about barrier performance are discussed in addition to the sequence of events and lessons learned. When it comes to management of risk and decision-making based upon results from risk analyses, this is discussed separately in a book published in parallel with my colleague at University of Stavanger, Professor Terje Aven, also published by Springer in 2007. Interested readers are referred to this work, ‘Risk Management, with Applications from the Offshore Petroleum Industry’

PrefacexThanksare also expressed to SpringerLondonpublishers,inparticularProfes-sor Pham and Senior Editor Anthony Doyle, for agreeing to publish the secondeditionofthisbook,andforproviding inspiringand valuableadvicethroughouttheprocess. Simon Rees has given valuable assistance and support during productionofthecamera-readymanuscript.AppendixApresents an overviewof some ofthe important softwaretools thatare commonlyused.Thanksto all the consultancies and software suppliers whohaveprovidedtheinformationrequiredforthisappendix.In preparing the second edition of the book, I have been fortunate to havekindassistance from many colleagues and friends,who have provided invaluablesupport and assistance.First of all I want to express sincerethanks and gratitude tomyfriendDavidRBayly,Crandon Consultants,whohasalsothis timeassistedwith improvement of the English language, as well as providing technicalcomments and suggestions.I don't know howI could havereached the same resultwithout David'skindassistance.My colleague at Uis, Professor Terje Aven has contributed significantly to thediscussion of statistical treatment of risk and uncertainty.I am very pleased thatthisimportantimprovementhas beenmade.DrHaiboChen,ScandpowerRiskManagement Beijing Inc has contributedvaluabletext regarding the analysis ofDPsystems onmobileinstallations.Safetec Nordic As has allowed use of several of their tools as input to thedescriptions andcases.I wantto express mygratitudefor allowingthis,and inpar-ticular express thanks to the following, Thomas Eriksen, Stein Haugen and Arn-stein Skogset.There are also several peoplewhohave contributed with relevant informationon various technical details; Finn Wickstrom, Aker Kvaerner and Graham Dalzell,TBs.My daughter, Margrete, has assisted in the editing of the manuscript. Manythanks to all of you.Bryne, January2007Jan Erik VinnemProfessorUniversityof Stavanger

x Preface Thanks are also expressed to Springer London publishers, in particular Profes￾sor Pham and Senior Editor Anthony Doyle, for agreeing to publish the second edition of this book, and for providing inspiring and valuable advice throughout the process. Simon Rees has given valuable assistance and support during production of the camera-ready manuscript. Appendix A presents an overview of some of the important software tools that are commonly used. Thanks to all the consultancies and software suppliers who have provided the information required for this appendix. In preparing the second edition of the book, I have been fortunate to have kind assistance from many colleagues and friends, who have provided invaluable support and assistance. First of all I want to express sincere thanks and gratitude to my friend David R Bayly, Crandon Consultants, who has also this time assisted with improvement of the English language, as well as providing technical comments and suggestions. I don’t know how I could have reached the same result without David’s kind assistance. My colleague at UiS, Professor Terje Aven has contributed significantly to the discussion of statistical treatment of risk and uncertainty. I am very pleased that this important improvement has been made. Dr Haibo Chen, Scandpower Risk Management Beijing Inc has contributed valuable text regarding the analysis of DP systems on mobile installations. Safetec Nordic AS has allowed use of several of their tools as input to the descriptions and cases. I want to express my gratitude for allowing this, and in par￾ticular express thanks to the following; Thomas Eriksen, Stein Haugen and Arn￾stein Skogset. There are also several people who have contributed with relevant information on various technical details; Finn Wickstrøm, Aker Kvaerner and Graham Dalzell, TBS3 . My daughter, Margrete, has assisted in the editing of the manuscript. Many thanks to all of you. Bryne, January 2007 Jan Erik Vinnem Professor University of Stavanger

ContentsIntroduction1.1AboutQRA1.2QRAinRelationtoOtherAnalysisMethods1.3ObjectivesandLimitations1.4RelevantRegulationsandStandards51.5Norwegian Regulations.61.5.1FrameworkRegulations1.5.2HESManagementRegulations1.5.3Facilities Regulations801.5.4ActivitiesRegulations101.5.5NMDRiskAnalysis Regulations101.6UKRegulations..101.6.1SafetyCaseRegulations111.6.2PFEERRegulations.121.6.3ManagementandAdministrationRegulations121.6.4DesignandConstructionRegulations121.7NationalandInternationalStandards131.8Limitations131.8.1RiskManagement131.8.2Subsea Production.141.8.3Production Regularity..152RiskPicture-DefinitionsandCharacteristics.152.1DefinitionofRisk.152.1.1BasicExpressionsofRisk.162.1.2Dimensionsof Risk...172.1.3Fatality Risk232.1.4Frequency of Impairment.242.1.5EnvironmentRisk2.1.6 Asset Risk...25

Contents 1 Introduction. 1 1.1 About QRA. 1 1.2 QRA in Relation to Other Analysis Methods . 3 1.3 Objectives and Limitations . 4 1.4 Relevant Regulations and Standards. 4 1.5 Norwegian Regulations. 5 1.5.1 Framework Regulations . 6 1.5.2 HES Management Regulations . 7 1.5.3 Facilities Regulations . 8 1.5.4 Activities Regulations . 9 1.5.5 NMD Risk Analysis Regulations . 10 1.6 UK Regulations. 10 1.6.1 Safety Case Regulations. 10 1.6.2 PFEER Regulations. 11 1.6.3 Management and Administration Regulations . 12 1.6.4 Design and Construction Regulations . 12 1.7 National and International Standards. 12 1.8 Limitations. 13 1.8.1 Risk Management. 13 1.8.2 Subsea Production. 13 1.8.3 Production Regularity . 14 2 Risk Picture – Definitions and Characteristics . 15 2.1 Definition of Risk . 15 2.1.1 Basic Expressions of Risk . 15 2.1.2 Dimensions of Risk . 16 2.1.3 Fatality Risk . 17 2.1.4 Frequency of Impairment . 23 2.1.5 Environment Risk. 24 2.1.6 Asset Risk. 25

Contentsxii262.2RiskElements262.2.1Personnel Risk.262.2.2Riskto Environment272.2.3Risk to Assets.282.3RiskPresentation292.3.1FatalityRisk342.3.2 Group Risk2.3.3ImpairmentRisk372.3.4RisktoEnvironment.37392.3.5 Asset Risk...2.3.6Load Distribution Functions.40.412.4Uncertainties...412.4.1BasisforUncertaintyConsideration422.4.2InfluenceofUncertainty432.4.3CalculationBasedonObservations...452.5BasicRiskModellingConcepts..452.5.1Defence inDepth.2.5.2 Barriers....462.5.3 Root Causes.492.5.4Risk InfluencingFactors50513RiskPresentationandRiskAcceptanceCriteria513.1 Risk Picture, North Sea..513.1.1OverviewofFatalAccidents.533.1.2OverviewofAccidentstoPersonnel543.1.3Fatal Accident Rates.553.1.4 Trends in Fatality Rates...573.1.5RiskLevelforHelicopterTransport..603.1.6ComparisonOffshore-OnshoreActivity.613.1.7 Risk Potential.623.2RiskAcceptanceCriteria.623.2.1Definition..633.2.2Philosophical Dilemma.643.2.3NorwegianRegulatoryRequirements3.2.4RiskAcceptanceCriteriaRequirementsbyUKRegulations.653.2.5NORSOKRequirements.673.3CriteriausedforPersonnelRiskbyPetroleumIndustry..68.693.3.1Group AverageRisk..693.3.2Risk Distribution.703.3.3Potential LossofLife(PLL)703.4RiskAcceptanceCriteriaforEnvironmental SpillRisk713.4.1 Initial Approach..713.4.2CurrentApproach.3.4.3SuitableCriteria?...74753.4.4NewApproach.753.5RiskofMaterialDamage/ProductionDelay763.6RiskAcceptanceCriteriaforTemporaryPhases

xii Contents 2.2 Risk Elements . 26 2.2.1 Personnel Risk. 26 2.2.2 Risk to Environment. 26 2.2.3 Risk to Assets. 27 2.3 Risk Presentation . 28 2.3.1 Fatality Risk . 29 2.3.2 Group Risk . 34 2.3.3 Impairment Risk. 37 2.3.4 Risk to Environment. 37 2.3.5 Asset Risk. 39 2.3.6 Load Distribution Functions. 40 2.4 Uncertainties . 41 2.4.1 Basis for Uncertainty Consideration . 41 2.4.2 Influence of Uncertainty. 42 2.4.3 Calculation Based on Observations. 43 2.5 Basic Risk Modelling Concepts. 45 2.5.1 Defence in Depth. 45 2.5.2 Barriers. 46 2.5.3 Root Causes. 49 2.5.4 Risk Influencing Factors . 50 3 Risk Presentation and Risk Acceptance Criteria. 51 3.1 Risk Picture, North Sea. 51 3.1.1 Overview of Fatal Accidents. 51 3.1.2 Overview of Accidents to Personnel . 53 3.1.3 Fatal Accident Rates. 54 3.1.4 Trends in Fatality Rates. 55 3.1.5 Risk Level for Helicopter Transport. 57 3.1.6 Comparison Offshore – Onshore Activity. 60 3.1.7 Risk Potential . 61 3.2 Risk Acceptance Criteria . 62 3.2.1 Definition . 62 3.2.2 Philosophical Dilemma . 63 3.2.3 Norwegian Regulatory Requirements . 64 3.2.4 Risk Acceptance Criteria Requirements by UK Regulations . 65 3.2.5 NORSOK Requirements . 67 3.3 Criteria used for Personnel Risk by Petroleum Industry. 68 3.3.1 Group Average Risk. 69 3.3.2 Risk Distribution . 69 3.3.3 Potential Loss of Life (PLL) . 70 3.4 Risk Acceptance Criteria for Environmental Spill Risk . 70 3.4.1 Initial Approach . 71 3.4.2 Current Approach. 71 3.4.3 Suitable Criteria?. 74 3.4.4 New Approach . 75 3.5 Risk of Material Damage/Production Delay. 75 3.6 Risk Acceptance Criteria for Temporary Phases . 76