Introduction3assessmentsaspartof thesafetycasesforbothexistingandnewinstallations.Theuseof QRA studies wasrapidlyexpandedunderthenewregulations.It isworthnoting that the scepticism regarding the useof QRA studies which existed beforethePiperAlphadisasteris still strong insomefora.The next step in this brief historical review is the blast and fire research carriedout as part of the (BFETS)programme (SCI, 1998) which was undertaken in theperiod1996-98,BlastandFireEngineeringforTopsideSystems.This hasfocusedattention on the high blast loads caused by possible gas explosion scenarios on theplatforms.Asa result of thiswork considerableattention is nowbeinggiven toevaluatinghowexplosion scenarios may be included probabilistically in QRAmodels.NPDpublished a new setofregulations in2001,which replaced therisk analy-sis and technical regulations from 1January 2002.The requirement for risk analy-sis and other analyses are stipulated in the Health, Environment and Safety (HES)Management regulations.These regulations haverequirements for analysis of riskas well as requirements for the definition of risk acceptance criteria.NPD wasdivided into twoorganisationsfrom1January2004,the safetydivision of NPDwas separated as a new organisation, and given the name Petroleum SafetyAuthority (PSA)[Norway].At the same time, PSA took over the responsibilityfor6 onshorefacilities in thepetroleum sector,terminals and refineries.The HEsManagementregulationsarecontrolledbyPSAThe Safety Case regulations weremodified in 2005;these revisions came intoforcefrom5April2006Thestructureof the Norwegian regulations changes in 2007,due to theneed tointegrate more fully the regulations for offshore and onshore facilities.There islittleornomaterial changeforoffshoreinstallations.1.2ORAinRelationtoOtherAnalysisMethods'Risk analysis'has been theterm usedbyNorwegian authorities(NPD,1990)forall systematic approaches torisk assessment, includingqualitativeas well asquan-titativeanalysis.This covers:HazardandOperabilityStudy(HAZOP)Safetyand OperabilityStudy (SAFOP).Safe Job Analysis (SJA)Preliminary Hazard Analysis (PHA)Failure Mode andEffect Analysis (FMEA)QuantitativeRiskAnalysis (QRA)The first five items on this list are essentially qualitative approaches, althoughsome of these techniques may be used in a semi-quantitative fashion.The last itemisaquantitativeapproach.Ithasbeenadisadvantagethatnospecifictermhasbeenused inNorwegianlegislationtodifferentiateQRAfromthequalitativetechniquesDiscussion of requirements has often been rather unclear,as no distinction has
Introduction 3 assessments as part of the safety cases for both existing and new installations. The use of QRA studies was rapidly expanded under the new regulations. It is worth noting that the scepticism regarding the use of QRA studies which existed before the Piper Alpha disaster is still strong in some fora. The next step in this brief historical review is the blast and fire research carried out as part of the (BFETS) programme (SCI, 1998) which was undertaken in the period 1996–98, Blast and Fire Engineering for Topside Systems. This has focused attention on the high blast loads caused by possible gas explosion scenarios on the platforms. As a result of this work considerable attention is now being given to evaluating how explosion scenarios may be included probabilistically in QRA models. NPD published a new set of regulations in 2001, which replaced the risk analysis and technical regulations from 1 January 2002. The requirement for risk analysis and other analyses are stipulated in the Health, Environment and Safety (HES) Management regulations. These regulations have requirements for analysis of risk as well as requirements for the definition of risk acceptance criteria. NPD was divided into two organisations from 1 January 2004, the safety division of NPD was separated as a new organisation, and given the name Petroleum Safety Authority (PSA) [Norway]. At the same time, PSA took over the responsibility for 6 onshore facilities in the petroleum sector, terminals and refineries. The HES Management regulations are controlled by PSA. The Safety Case regulations were modified in 2005; these revisions came into force from 5 April 2006. The structure of the Norwegian regulations changes in 2007, due to the need to integrate more fully the regulations for offshore and onshore facilities. There is little or no material change for offshore installations. 1.2 QRA in Relation to Other Analysis Methods >Risk analysis= has been the term used by Norwegian authorities (NPD, 1990) for all systematic approaches to risk assessment, including qualitative as well as quantitative analysis. This covers: x Hazard and Operability Study (HAZOP) x Safety and Operability Study (SAFOP) x Safe Job Analysis (SJA) x Preliminary Hazard Analysis (PHA) x Failure Mode and Effect Analysis (FMEA) x Quantitative Risk Analysis (QRA) The first five items on this list are essentially qualitative approaches, although some of these techniques may be used in a semi-quantitative fashion. The last item is a quantitative approach. It has been a disadvantage that no specific term has been used in Norwegian legislation to differentiate QRA from the qualitative techniques. Discussion of requirements has often been rather unclear, as no distinction has
4OffshoreRisk Assessmentbeen made between the different types of risk analysis. Only the quantitativeapproach,QRA,isdiscussed inthisbook.1.3Objectives andLimitationsThis book is essentially focused onapplications of QRA in theoffshore oil and gasindustry.Theobjectives ofthis book are as follows:1.ToprovideguidanceabouttheperformanceofQRAstudiesforoffshoreinstallations andmarinestructures2.To showhowtools,approaches and datamaybeused effectivelyto ensurethat QRA studies provide useful input to risk based decision-making.3.Todemonstratehowthe best practice is being carried out.4.To demonstrate what is new knowledgefrom recentresearch activitiesduring thelastfiveyears.5Toprovide someperspective on issuesthathavenotyetbeen sufficientlyresolved.The discussion of modelling is alsoapplication oriented.Modelling of hazards istherefore relatedtothemostprominent hazardsforoffshore installations:Fire.Explosion.CollisionMarinehazardsOther hazards such as falling objects are also addressed, but somewhat morebriefly.Risk to personnel is addressed most thoroughly, but also risk to the environ-ment and material damage risk are covered. No methodology for environmentalrisk assessment is discussed, this is an area where several approaches are still beingattemptedandnoagreementhasyetbeenreached onarecommendedapproachMostQRAworkhasbeendevotedtoriskassessmentduringthedesignphaseTheuseofriskassessmentduringtheoperationsphaseisalso importantandthus asignificant part of this book is devoted to this phase.Recent research has focusedon the operations phase,which will bediscussed in somedepth.All illustrations and cases that are presented are mostly related to offshoreinstallations and marine structures involved in offshore oil and gas explorationproduction and transportation.Consideration is also givento aspects related to thetransportationofpersonnel and suppliestotheinstallations.1.4RelevantRegulationsand StandardsThere are several countries that have legislation that call for the use of QRAstudies in the design and operation of offshore installations:
4 Offshore Risk Assessment been made between the different types of risk analysis. Only the quantitative approach, QRA, is discussed in this book. 1.3 Objectives and Limitations This book is essentially focused on applications of QRA in the offshore oil and gas industry. The objectives of this book are as follows: 1. To provide guidance about the performance of QRA studies for offshore installations and marine structures. 2. To show how tools, approaches and data may be used effectively to ensure that QRA studies provide useful input to risk based decision-making. 3. To demonstrate how the best practice is being carried out. 4. To demonstrate what is new knowledge from recent research activities during the last five years. 5. To provide some perspective on issues that have not yet been sufficiently resolved. The discussion of modelling is also application oriented. Modelling of hazards is therefore related to the most prominent hazards for offshore installations: x Fire x Explosion x Collision x Marine hazards Other hazards such as falling objects are also addressed, but somewhat more briefly. Risk to personnel is addressed most thoroughly, but also risk to the environment and material damage risk are covered. No methodology for environmental risk assessment is discussed, this is an area where several approaches are still being attempted and no agreement has yet been reached on a recommended approach. Most QRA work has been devoted to risk assessment during the design phase. The use of risk assessment during the operations phase is also important and thus a significant part of this book is devoted to this phase. Recent research has focused on the operations phase, which will be discussed in some depth. All illustrations and cases that are presented are mostly related to offshore installations and marine structures involved in offshore oil and gas exploration, production and transportation. Consideration is also given to aspects related to the transportation of personnel and supplies to the installations. 1.4 Relevant Regulations and Standards There are several countries that have legislation that call for the use of QRA studies in the design and operation of offshore installations:
5IntroductionUnitedKingdomCanadaAustralia.NorwayThefollowing is a brief summary of the requirements of the legislation in thesecountriesexceptforUKandNorway,whicharediscussedinsomedepththroughouttheremainderofthischapter:Canada (Newfoundland and Labradoroffshoreareas)Inassociationwithnewdevelopmentproposals,a ConceptOSafety Analysis is required.The field development proposalneeds to define how this will be met, and state theTargetLevelsofSafetythathavebeensetasacceptancecriteriaforrisk.The development proposal shall also define a“Risk Assess-Oment Plan'which should contain a listing ofthevarious spe-cific risk and safety analyses thatmay berequired as detaileddesign proceeds.It should also provide a plan for the comple-tion of these studies and analyses and an explanation of howthis process is integrated into the design process.Finally,itshould provide an explanation of the methodologies to be uti-lisedandadiscussionoftheirvalidityandrelevanceintheoverall process.AustraliaPetroleum(Submerged Lands)(Management ofSafetyonoOffshoreFacilities)Regulations1996,NOPSA(1996)These regulations call for Safety Cases to be prepared for alloinstallations and to demonstrate that risks have been reducedtoalevelthatisas lowasreasonablypracticable(ALARP)TheNationalOffshorePetroleumSafetyAuthority(NOPSA)has also issued Safety CaseGuidelines,NOPSA (2004)There are also several other countries wherevoluntary schemesaredominating,forinstancedueto companypolicies, such as bythe Shell Group.The main emphasis in the following is on legislation in UK and Norway, wheretherelevantrequirementswithrespecttoriskassessmentandriskmanagementarebrieflyintroduced.1.5NorwegianRegulationsPSA has since 2002five regulations which control safety of design and operationofoffshoreinstallations (slightmodificationsfrom2o07notconsidered)
Introduction 5 x United Kingdom x Canada x Australia x Norway The following is a brief summary of the requirements of the legislation in these countries except for UK and Norway, which are discussed in some depth throughout the remainder of this chapter: x Canada (Newfoundland and Labrador offshore areas) o In association with new development proposals, a Concept Safety Analysis is required. The field development proposal needs to define how this will be met, and state the ‘Target Levels of Safety’ that have been set as acceptance criteria for risk. o The development proposal shall also define a ‘Risk Assessment Plan’ which should contain a listing of the various specific risk and safety analyses that may be required as detailed design proceeds. It should also provide a plan for the completion of these studies and analyses and an explanation of how this process is integrated into the design process. Finally, it should provide an explanation of the methodologies to be utilised and a discussion of their validity and relevance in the overall process. x Australia o Petroleum (Submerged Lands) (Management of Safety on Offshore Facilities) Regulations 1996, NOPSA (1996) o These regulations call for Safety Cases to be prepared for all installations and to demonstrate that risks have been reduced to a level that is as low as reasonably practicable (ALARP). o The National Offshore Petroleum Safety Authority (NOPSA) has also issued Safety Case Guidelines, NOPSA (2004). There are also several other countries where voluntary schemes are dominating, for instance due to company policies, such as by the Shell Group. The main emphasis in the following is on legislation in UK and Norway, where the relevant requirements with respect to risk assessment and risk management are briefly introduced. 1.5 Norwegian Regulations PSA has since 2002 five regulations which control safety of design and operation of offshore installations (slight modifications from 2007 not considered):
OffshoreRiskAssessment6Regulations relating to health, environment and safety in the petroleumactivities(theFrameworkregulations,PSA,2002a)Regulations relating to management in the petroleum activities (theManagementregulations,PSA,2002b)Regulations relating to design and outfitting of facilities etc.,in the petro-leumactivities(theFacilitiesregulations,PSA,2002c)Regulations relating to conduct of activities in the petroleum activities (theActivitiesregulations,PSA,2002d)Regulations relatingtomaterial and information in thepetroleumactivities(the Information duty regulations, PSA, 2002e)1.5.1FrameworkRegulationsThis is a high level regulation which has the overall principles that are spelled outinmore detail in theother regulations.One of therequirements is notfound in anyother regulation,this is the Norwegian equivalent of the so-called ALARP evalu-ation(ALARP-AsLowAsReasonablyPracticable,seeSection1.6.1),seethecopyof Section9belowIt is in particular the first and second paragraphs of Section 9 that definerequirements forrisk reductionthatfollowcloselythe interpretationofALARPinUKregulationsSection9Principles relatingtorisk reductionHarm or danger of harm to people,the environment or tofinancial assets shallbeprevented or limited in accordancewith the legislation relating tohealth,theenvironmentand safety,including internal requirements and acceptancecriteria.OverandabovethisleveltheriskshallbefurtherreducedtotheextentpossibleAssessmentsonthebasisofthisprovisionshallbemadeinallphasesofthepetroleum activities.In effectuating risk reduction the party responsible shall choose the technical,operational or organisational solutions which according to an individual as wellasanoverall evaluationofthepotentialharmandpresentandfutureuseofferthebest results,providedtheassociated costs arenot significantlydisproportionatetotheriskreductionachieved.If there is insufficient knowledge about the effects that use of the technical.operational or organisational solutions may have on health, environment andsafety,solutions that will reduce this uncertainty shall be chosen.Factorswhichmaycauseharm,ornuisancetopeople,theenvironmentortofinancialassetsinthepetroleumactivitiesshallbereplacedbyfactorswhichinanoverallevaluationhavelesspotentialforharm,ornuisanceSection9of theFrameworkregulationshas notbeenfocused onsignificantlyinthe first few years since the regulations were stipulated.This is gradually beingchanged, starting from 2006.ThePetroleum Safety Authority started in the secondhalf of 2005an initiative,to increasethefocusonthis section of theFrameworkregulations
6 Offshore Risk Assessment x Regulations relating to health, environment and safety in the petroleum activities (the Framework regulations, PSA, 2002a) x Regulations relating to management in the petroleum activities (the Management regulations, PSA, 2002b) x Regulations relating to design and outfitting of facilities etc., in the petroleum activities (the Facilities regulations, PSA, 2002c) x Regulations relating to conduct of activities in the petroleum activities (the Activities regulations, PSA, 2002d) x Regulations relating to material and information in the petroleum activities (the Information duty regulations, PSA, 2002e) 1.5.1 Framework Regulations This is a high level regulation which has the overall principles that are spelled out in more detail in the other regulations. One of the requirements is not found in any other regulation, this is the Norwegian equivalent of the so-called ALARP evaluation (ALARP – As Low As Reasonably Practicable, see Section 1.6.1), see the copy of Section 9 below. It is in particular the first and second paragraphs of Section 9 that define requirements for risk reduction that follow closely the interpretation of ALARP in UK regulations. Section 9 Principles relating to risk reduction Harm or danger of harm to people, the environment or to financial assets shall be prevented or limited in accordance with the legislation relating to health, the environment and safety, including internal requirements and acceptance criteria. Over and above this level the risk shall be further reduced to the extent possible. Assessments on the basis of this provision shall be made in all phases of the petroleum activities. In effectuating risk reduction the party responsible shall choose the technical, operational or organisational solutions which according to an individual as well as an overall evaluation of the potential harm and present and future use offer the best results, provided the associated costs are not significantly disproportionate to the risk reduction achieved. If there is insufficient knowledge about the effects that use of the technical, operational or organisational solutions may have on health, environment and safety, solutions that will reduce this uncertainty shall be chosen. Factors which may cause harm, or nuisance to people, the environment or to financial assets in the petroleum activities shall be replaced by factors which in an overall evaluation have less potential for harm, or nuisance. Section 9 of the Framework regulations has not been focused on significantly in the first few years since the regulations were stipulated. This is gradually being changed, starting from 2006. The Petroleum Safety Authority started in the second half of 2005 an initiative, to increase the focus on this section of the Framework regulations
IntroductionAnothersubjectwhichisfocussed intheFrameworkregulationsisemergencypreparedness.Theoverallrequirementstoemergencyplanninganddimensioningofsystems arenot spelled out inmoredetail inotherregulations.1.5.2HESManagementRegulationsThereareseveral sections intheHESManagementregulations thatare important,withrespecttoanalysisofriskanalysisofbarriers,andriskacceptancecriteriaTwo sections in the Management regulations areparticularly importantwithrespectto analysis ofmajor accident risk and quantitativeriskanalysis, thesetwosectionsaregiveninfullbelow:Section14AnalysisofmajoraccidentriskQuantitativerisk analyses and other necessary analyses shall be carried out toidentifycontributorstomajoraccidentrisk,includingshowingthe risk connected with planned drilling and well activities, and show whicha)effecttheseactivitieshaveonthetotalriskonthefacilityb)the effect of modifications and the carrying out of modifications on the totalrisk,therisk connected withtransportation of personnel between thecontinentalC)shelfandshoreandbetweenfacilities.The analyses shall in addition beused to setconditions for operation and toclassifyareas,systemsandequipmentwithrespecttorisk.Section15Quantitativeriskanalysesandemergencypreparedness analysesQuantitative risk analyses which provide a balanced and as comprehensivepicture as possible of the risk shall be carried out.The risk analyses shallidentify situations of hazard and accident, select initiating incidents and map2thecausesoftheincidents,b)carry out modelling of accident sequences and consequences so that, amongother things, possible dependencies between physical barriers can berevealed, and sothat the requirements that must be set in respect of theperformanceofthebarriers,canbecalculated,：classifyimportantsafetysystems.d)showthatthemainsafetyfunctionsareadequatelyprovidedfor,identifydimensioning accidental loads,eprovide thebasis for selecting thedefined situations of hazard and accident.f1Necessarysensitivity calculations and evaluations of uncertainties shall becarried out.Emergency preparedness analyses shall be carried out which shalla)define situations of hazardand accident,b)setperformancerequirementstotheemergencypreparedness,c)selectanddimensionemergencypreparednessmeasures
Introduction 7 Another subject which is focussed in the Framework regulations is emergency preparedness. The overall requirements to emergency planning and dimensioning of systems are not spelled out in more detail in other regulations. 1.5.2 HES Management Regulations There are several sections in the HES Management regulations that are important, with respect to analysis of risk, analysis of barriers, and risk acceptance criteria. Two sections in the Management regulations are particularly important with respect to analysis of major accident risk and quantitative risk analysis, these two sections are given in full below: Section 14 Analysis of major accident risk Quantitative risk analyses and other necessary analyses shall be carried out to identify contributors to major accident risk, including showing a) the risk connected with planned drilling and well activities, and show which effect these activities have on the total risk on the facility, b) the effect of modifications and the carrying out of modifications on the total risk, c) the risk connected with transportation of personnel between the continental shelf and shore and between facilities. The analyses shall in addition be used to set conditions for operation and to classify areas, systems and equipment with respect to risk. Section 15 Quantitative risk analyses and emergency preparedness analyses Quantitative risk analyses which provide a balanced and as comprehensive picture as possible of the risk shall be carried out. The risk analyses shall a) identify situations of hazard and accident, select initiating incidents and map the causes of the incidents, b) carry out modelling of accident sequences and consequences so that, among other things, possible dependencies between physical barriers can be revealed, and so that the requirements that must be set in respect of the performance of the barriers, can be calculated, c) classify important safety systems, d) show that the main safety functions are adequately provided for, e) identify dimensioning accidental loads, f) provide the basis for selecting the defined situations of hazard and accident. Necessary sensitivity calculations and evaluations of uncertainties shall be carried out. Emergency preparedness analyses shall be carried out which shall a) define situations of hazard and accident, b) set performance requirements to the emergency preparedness, c) select and dimension emergency preparedness measures