What’s inside...

03 TheSeven Borealis -AWorld-ClassStrategicEnabler

04 OnTargettoDeliverFirstCommercialAIV

05 Hyperflow®RiserTowers–AnInnovativeUltraDeepwaterSolution

06 MechanicalLinedPipeInstallationbyReel-layoffersSignificantCostSavings

09 ReeledCladSCRWeldFatigueQualification

10 Seven AtlanticandNormand Subsea–OneYearOn

deepInnovativetechnologysolutionsforthesubseaindustry

ASubsea7publication-May2011

www.subsea7.com seabed-to-surface

Newtechnologyforpre-saltAmilestoneUS$1billionSURFcontractbyPetrobrasforfourdecoupledrisersystemstobeinstalledintheGuará-LulaNEfields,Brazil,inwaterdepthsofbeyond2,100metres.

3D animation model showingone of the 2,000t buoys

WelcometothefirstissueofthenewDeep7,aSubsea7publicationfocussingoninnovativetechnologyforthesubseaindustry.Prior to their merger and formation into the new Subsea 7 in January 2011, Subsea 7 and Acergy were renowned within the Subsea industry for their implementation of new technology. An ongoing commitment to embracing new technology will underpin much of the way we execute our work and develop the company in the future.

The new Technology and Asset Development department is part of the Commercial Group, where our primary objective is to investigate industry requirements and opportunities and to develop future capabilities with significant strategic importance, in support of developing the business and winning tenders.

An important aspect of our approach will be the relationship we have with our clients and key partners, in particular, the contribution that third parties can make is of great value to Subsea 7 and it is therefore essential that this is encouraged. Our philosophy is largely an open door approach to parties that feel they have a technology that may be of mutual benefit and which has the potential to be of significant value to the Subsea industry.

In this first edition of the new Deep 7 we hope you will find information on technologies that are of benefit to you and your companies.

New technology for pre-salt ...cont’d from page 1

Subsea7hasbeenawardedamilestoneUS$1billionSubseaUmbilical,RiserandFlowline(SURF)contractbyPetrobrasforfourdecoupledrisersystemstobeinstalledintheGuará-LulaNEfieldslocatedintheSantosBasin,offshoreBrazil.Thisisthelargestengineering,procurement,installationandcommissioning(EPIC)SURFcontractawardedtodateinBrazil.

Despitetheirpotential,thepre-saltfielddevelopmentsliebeyond2,100mofseawaterandareextremelytechnicallychallenging,evenforacompanylikeSubsea7whichhasasuccessfultrackrecordinmanagingextremelylargeEPICprojects.

TheGuará-LulaNEprojectisbasedoninstallingfourverylargesubmergedbuoys(eachweighingaround2,000t)approximately250mbelowthesurface,alongwithtwenty-sevensteelcatenaryrisers(SCRs)of3.9km,ofwhicheighteenare7.5-inchproductionlines,three9.5-inchwaterinjectionlinesandsix8-inchgasinjectionlines,togetherwiththeassociatedretentionpiles,crossingsandpipelineendterminations.TheseSCRswillbereel-laidbytheSeven Oceans rigidpipelayvesselandhookeduptothesubmergedbuoys.

TheproductionandwaterinjectionlineswillbeconstructedpredominantlyfromMechanicalLinedPipe(BUTTINGBuBi®).ThisisaresultofajointdevelopmentprogrammebySubsea7andBUTTING,muchofwhichwaswitnessedbyPetrobras.BUTTINGBuBi®linedpipewastechnicallyqualified‘Fit-for-Service’byDNVincompliancewithDNVRPA–203.FindoutmoreontheBUTTINGBuBi®linedpipesolutiononpages6/7ofthisissueofDeep7.

DEEP7 May 2011

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To find out more about any of the technologies featured in this issue contact John Mair, Technology Development Director at john.mair@subsea7.com or email communications@subsea7.com

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The world’s biggest mast crane

Theinstallationofthe5,000tmastcrane,thelargestoffshoremastcraneeverconstructed,iscompleteandwillnowbefollowedbyfinalcommissioningandaloadtestingprogramme.ThecranefeaturesafullyheavecompensateddeepwaterloweringsystemandwillbeanimpressiveaspectoftheSeven Borealis’silhouette.

ThemastcranemaximisestheavailabilityofdeckspaceonboardtheSeven BorealisandiscapableoftheselfinstallationandremovalofsystemssuchastheJ-laytowerandafutureflex-laytower.

Thescaleandambitionoftheconversiontoaheavylift/pipelayvesselhascreatedanumberofchallengesandSubsea7hasbeenworkingcloselywiththeoriginaldesignerstooptimisethevessel’sdesign.

Theconversionprojectincludesthedesign,constructionandinstallationofastate-ofthe-art600tS-laysystemandinstallationofa1,000tJ-laytower.

Anumberofmaincomponentsforthe600tS-laysystem,includingthetensioners,stingerandstingersupportframe,havebeenspecificallydesignedfortheSeven Borealis.Thesystemwilloffertremendousflexibilityinhowthefiringlineisconfiguredandthetypesofpipelinesthevesselcanhandle,aswellasfeedingtheJ-laysystem.

Duringdelicatepipelayoperations,dampingtheeffectsofdisplacedloadsorwavemotioncanbecriticaltoensuringsafeandpreciseinstallation.TheSeven Borealisfeaturesanti-heelandanti-rollsystemsdesignedtoensureastableworkingenvironment,eveninchallengingseastatesandwhileworkingwithheavyloads.

Heeliscausedbyloadoffset,ortheunequaldistributionofweight.Onavesselofthisscale,withits5,000tmastcrane,theseoffsetloadscanbesignificant.Tocompensateheel,waterisautomaticallypumpedbetweenfivepairsofballasttanks.15pumps,eachcapableoftransferringupto13m3ofwaterperminute,keepthevesselbalancednomatterwherethecraneandloadarepositioned.

TheSeven Borealisalsohasa‘passive’rolldampingsystem,designedtoreducetherollmotioninducedbyheavyseastates.Fourlargeflumetanksareusedtocreateadditionalrolldamping.Thefillinglevelofthewaterineachtankisadjustedforspecificloadingconditionssuchthatthewaterwill

oscillateatthesamerollperiodastheship.However,thewatermovementisinanti-phasetotheship’srollandcreatesadampingeffectonthemotion.Theinternalstructurewithineachtankactsasabafflethatrestrictstheflowandinfluencesthedamping.Thiseffectisassessedthroughmodeltesting.Whenusedcorrectly,thetankscanreducetherollbyaround40%andthereforeincreasetheoperabilityofthevessel.

03

The Seven Borealis - A World-Class Strategic EnablerThe Seven Borealis (to be officially named), is Subsea 7’s world-class strategic enabler. The new pipelay / heavy lift vessel has been designed to meet the exacting requirements of ultra-deep and deepwater challenges, representing a significant leap forward in deepwater capabilities.

Key facts:

• Length182mxbreadth46m

• 600ttensionS-laysystemupto46-inchpipediameterutilising3tensioners

• 600tA&Rwinchutilising135mmdiameterwirefor3,000mwaterdepth

• 1,000ttoptensionJ-laysystemupto24-inchpipediameter

• 2,400tonboardpipestorage

• 5,000tmastcranewithaheavecompensateddeepwaterloweringsystem

• Accommodationfor400people

• 2xworkclassROVs

• Enhancedsurveycapability.

Forfurtherinformationpleasecontactstephane.abergel@subsea7.com

ThecranecapacitywillbetestedatitsfullcapacitybeforeinstallationoftheJ-laytower.

ThevesseliscurrentlyundergoingconversionattheSembawangshipyard,SingaporeafterwhichitwilltransittotheNetherlandsreadytoreceivepipelayequipment.TheSeven Borealisisduetobedeliveredduringthefirsthalfof2012.

“The crane is the world’s biggest mast crane. The top of the crane mast is 87m above the main deck”.

Subsea 7 has an ambitious plan to develop a series of Autonomous Inspection Vehicles (AIV), initially capable of general visual inspection, through to a fully capable work-class sized intervention vehicle.

AcombinedprojectteamcomprisinghardwaredevelopersandoperationalpersonnelfromSubsea7andSeebyte,aScottishbasedsoftwaredeveloperfortheautonomousroboticsmarket,hasbeenworkingtogethertodeliverthefirstvehicle.Throughthedevelopmentprocess,manytechnicalchallengeshavebeenovercomeandatthetimeofprint,thefirsttanktrialsandopenwatertestinghascommenced.

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DEEP7 May 2011

On Target to Deliver First Commercial ‘AIV’

Thevehicleisfullyautonomousandcanoperatefora24-hourperiodonasinglechargeofitslithium-ionbatteries,whicharehousedinpressurevesselswithinthehull.Thesebatterieshavebeenspecificallydesignedforthevehicleandprovideamorecost-effectivesolutiontopressuretolerantbatteries,withalowercapitalcostandmuchimprovedcyclelives.Thebatteriesarehousedwithtwoterabytesofonboarddatastoragewhichdownloadsasthebatteriesarechargedoffthevehicle.

Thesensorpackagehasbeendevelopedtocovertherequirementsofgeneralvisualinspection;itcomprisesthelatestsonartechnologycoupledwithhighqualityvideocamerasandlowpowerLEDlighting.

Asignificantsoftwareintegrationanddevelopmentprojecthasbeenrunninginparallelwiththehardwaredevelopmentandthistoohasusedthemostadvancedtechniquestomanage,debugandcontrolthedevelopment.Thedevelopmentprogrammehasbeenaugmentedbytheextensiveanduniqueuseofsimulators,bothintheindividualsoftwaremoduledesignandtestingandtheintegratedsystem.Byusingasurfaceversionofthe

“First commercial vehicle will be available in late 2011”

subseaelectronicsandanadvancedcustombuiltsimulator,thesoftwaredevelopmentteamhasachieved1000’sofhoursofsimulatedmissions,longbeforethevehiclehardwarewasreadyforthewater.

WithanA-framedeploymentsystemanddedicatedbasket,theAIVwillbereadyforoperationsfromtraditionalsupportvesselsdeployingsingleormultipleunitsandalsofromFPSOsforsupportvesselfreeoperations.

ThefirstcommercialAIVwillbeavailableinlate2011followingextensivein-watertestingandcapabilitydevelopment.

Forfurtherinformationcontacthugh.ferguson@subsea7.com

Vehicle Commissioning trials in autonomous mode

TheshapeofthevehiclehaschangedfromtheoriginaldesignconceptduetothesignificantworkdoneusingthelatestCFDM(ComputationalFluidDynamicsModelling)tooptimisethevehicle’sshapewithregardtostabilityandmanoeuvrability,whileconservingtheonboardpowerresources.UnliketraditionalRemotelyOperatedVehicles,theAIVisbasedaroundafibreglassmonocoquehulldesignwiththestructuralstrengthcomingfromthepressurehullswithin.Thedesignhasresultedinaverycompactandrigiddesignwithouttheneedforheavystructuralframemembers.

Subsea 7 first adopted the Hyperflow® Hybrid Riser Tower on the Total Girassol Deepwater Development Project, Angola, during 1999, connecting three free-standing riser towers to the FPSO by flexible jumpers.

HybridRiserTowershavenowbecomeoneofthemostinvestigatedsolutionsatbidstageforultradeepwaterfielddevelopments,duetotheircapabilitytoaccommodatelargediameterrisers,reducedloadonFPSOsanddemandingflowassurancerequirements.Theyallowarobustlayoutwithalargeflexibilityforfutureexpansionsofthefield.

BasedonitsexperienceandthelessonslearnedalongtheGirassoldevelopmentandmorerecentlytheGreaterPlutonioproject,alsoinAngola,Subsea7hasdevelopeda“preferred”architectureoftheHybridRiserTower.ThepreferredarchitecturewassubjectedtoaFailureMode,EffectsandCriticalityAnalysis(FMECA),coveringitsdesign,fabrication,installationandin-servicelife.Thisthoroughreviewprovided:

• atechnicalhierarchyofsystem/sub-system/unit/equipment/partthatsetsinperspectivealltheelementsoftherisertower;thisisthecommonbasisforthestandardisationofbothengineeringandprocurementinviewofreductionofcostanddelivery

• asemi-quantitativemethodoffailureassessmenttoensurethatanyriskassociatedwiththedesignorconstructionwasadequatelymitigated

Asatypicalexample,largeheatlossesgeneratedbyconvectionheattransferismitigatedbyusingseparatematerialforinsulationandbuoyancy.

Hyperflow®isatrademarkofSubsea7,patentsandpatentspending.

Hybrid Hyperflow® Riser Towers – An Innovative Ultra Deepwater Solution

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Many of the Hyperflow® Hybrid Riser Towers have been fabricated at Subsea 7’s Sonamet Yard in Lobito, Angola

TheHyperflow®HybridRiserTowerconsistsofabundleofrisersofvaryingdiameterandfunction(production,waterandgasinjection,serviceline,gasliftriser)bundledtogether.

Thebottomoftherisertowerisanchoredbyaflexiblejointtoalockingdevicewhichanchorsthetowerfirmlytotheseabed.Thetopoftherisertowerbundleisconnectedtoabuoyancytankwhichmaintainsitintension.ThetopsoftherisersareinturnconnectedwithflexiblejumperstotheFPSO.

TheHybridRiserTowerensuresefficientprojectdelivery,providingafastroutetofirstoil.ThesystemcanbeinstalledpriortothearrivaloftheFPSOon-siteandquicklyconnected.

Technology Development

Thereelingprocessimposesplasticstrainsonthepipewhichcanpotentiallycausewrinklingintheliner.Theinitialdevelopmentprojectwasthereforesplitintofivephasestoaddressthisissue:

1. Finite Element Modelling

Adetailed3DFiniteElement(FE)modelwasdevelopedtosimulatecyclicstrainingoflinedpipeinactualtestrigloadingconditions.

GoodcorrelationbetweentheFEanalysisresultsandthefull-scalebendingtrialsallowtheFEmodeltobeusedwithconfidencetoinvestigatetheeffectsofdifferentpipesizesandmaterialcombinations.

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DEEP7 May 2011

Mechanical Lined Pipe Installation by Reel-lay offers Significant Costs Savings

2. Reel-lay Simulation test rig

ThebendingtestrigatHeriot-WattUniversityEdinburgh,Scotlandwasusedtoperformsimulatedreelingtestswherebendingandstraighteningcycleswererepeatedonavarietyofpipesizesandmaterialcombinations,bothwithandwithoutmoderate,internalpressuretoreplicatethefullreelingandinstallationprocedureonthevessel.

TheBuBi®bendingtrialsthereforedemonstratedthattheSubsea7installationmethodologyincombinationwiththeBUTTINGmanufacturingprocesscanpreventformationofwrinklinginthelinerduringreeling.

In many instances, there is a significant economical prize to be gained by using a mechanical lined pipe alternative such as the BUTTING BuBi® pipe for bundle and reel-lay applications as opposed to solid corrosion resistant alloys (CRAs) and metallurgically clad pipe, combined with the additional benefits of onshore fabrication.

Subsea7firstincorporatedtheBUTTINGBuBi®pipeintotheirbundlesin1995fortheBPCyrusprojectintheNorthSeaandsincethenthecompanyhassuccessfullyincorporatedtheproductintonumeroussubseabundleprojectswithatotallengthexceeding100kmnowdeployed.Thisdemonstratesthattheproductisbothcost-effectiveandafit-for-purposesolutiontoalternativepipelineoptions.

Buildinguponthisexperience,Subsea7andBUTTINGembarkeduponatechnologydevelopmentprogrammetoultimatelydemonstrateandqualifytheBuBi®linedpipeforreel-layinstallationforflowlinesandlowfatigueriserapplications.

Construction

TheBUTTINGBuBi®pipeisahighqualitymechanicallinedpipeconsistingofathinwalledcorrosionresistantlinerwhichistelescopicallyalignedinsideacarbonsteelpipeandthensubjectedtoauniforminternalhydraulicexpansion,resultinginapersistent,consistenttightgripbetweenthetwopipes.Thelinerisweldedtotheoutercarbonsteelpipewithasealweldapproximately50mmfromtheendofthepipeandthesectiontothepipeendoverlayedwithAlloy625resultinginahighqualityfatigueresistanttermination.

Unlikethemetallurgicallycladpipes,themechanicallylinedBuBi®pipe,bythenatureoftheconstructionprocesscanalsoofferalargevarietyofmaterialsizesandcombinationsofinnerandouterpipes.

Seven Oceans reel-laying pipe

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3. Fatigue Testing

ReeledsampleswerefatiguetestedonafullscaleresonancefatiguetestassemblyatTWI.

TheinspectionresultsconfirmedthattheBuBi®pipehadsufferednodetrimentalmechanicalorcorrosionimpactfromthereelingandfatiguetestingandthereforedemonstratedfurtherthattheBuBi®mechanicallinedpipecouldbereliablyinstalledbythereel-laymethod,evenfordynamicriserssubjecttomoderatefatiqueexposure.

4. DNV Qualification

ThedevelopmentprogrammewasexecutedinaccordancewiththeDNVrecommendedpracticefornewtechnologyqualificationDNVRPA-203resultinginSubsea7beingawarded-“Fitness-for-Purpose”oftheReelableBuBi®LinedPipeSystem.

Inparticular,thehighqualitymanufacturingprocessadoptedbyBUTTINGandthein-depthanalysisperformedbySubsea7ensurestherobustnessoftheinstalledproduct.

5. Safety

Anin-depthindependentreviewofallaspectsofthereelingandinstallationprocess,whilstmaintaininganinternalpressurewithinthepipeline,hasbeenconductedandconcludedthatnospecialmeasuresneedtobeadopted.

BP Andrew Area Development Project, UK sector of the North Sea

TheSubsea7workscopeistoengineer,procure,fabricate,installandcommissiona28kmpipelinebundlesystemconsistingofproduction,gasliftandmethanolpipelines.Thepipelinebundlesystemconsistsoffourdaisychainpipelinebundles(totallingapprox.28km)interconnectedbyrigidspooljumpers.ThisparticularprojectfurtherdemonstratestheuniquedesignsavailablewithinthepipelinebundlerangeasitwillbethelongestbundleSubsea7hasproducedandinstalledtodate.Installationisexpectedtotakeplaceduringsummer2011.28kmof14-inchBuBi®linedpipehasbeenusedfortheAndrewbundle.

Apache North Sea Bacchus subsea development project, UK sector of the North Sea

TheSubsea7workscopeistoengineer,procure,fabricate,installandcommissiona7kmpipelinebundleconsistingofproduction,gaslift,methanolandheatingpipelinesandcontrolsumbilical.Thepipelinebundlesystem,installedusingtheControlledDepthTowMethodology,willconnectthreenewwellsattheBacchusdevelopmentinasubseatie-backtotheexistingFortiesAlphaplatform.13.4kmof6-inchand13.4kmof4-inchBuBi®linedpipehasbeenusedfortheBacchusbundle.

Petrobras Guará-Lula NE fields, Santos Basin, offshore Brazil

Ashighlightedonpage2ofthisissueofDeep7,Bubi®mechanicallinedpipewillalsobeusedinBrazil’spre-saltdevelopmentsintheGuará-LulaNEfields,SantosBasin,offshoreBrazil,whichliebeyond2,100mwaterdepth.

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Bundle launch at Wick, Scotland

RecentdevelopmentstouseBUTTINGBuBi®pipe

The installation of subsea systems is becoming ever increasingly challenging as equipment weights increase and the equipment becomes more sophisticated and sensitive to impact.

Arecentexampleisrotatingmachineryforsubseapumpingandprocessingapplications,nowbeingdeployedinbothshallowandultra-deeplocations.

Oneofthekeychallengesistheriskofresonanceduringdeploymentwhichmaypotentiallyhaveanumberofundesiredconsequencesi.e.:

• largeverticalmotionduringdockingontheseabedfoundation,leadingtounacceptableimpact

• largedynamictensioninthecablesduetoheaveorslackwire.

Thetraditionalcriteriaforthistypeofoffshoreoperationarebasedonenvironmentalcharacteristics(e.g.maximumsignificantwaveheight,peakperiodoftheseastate),thataredeterminedfromanalysesthatmaybeinaccurateastheyuseidealisedwaveconditions(singlepeakwavespectrum)andvesselmotionResponseAmplitudeOperators,whichcouldbeunderorover-estimated,particularlywhentheseaconditionismulti-directional(seaandswell),whichisoftenthecaseoffshoreWestAfricaandBrazil.

Subsea7hasdevelopedanin-houseMotionMonitoringSoftwarepackagethatrecordsandprocessesdatarelatedtotheheavemotionofthevesselviatheMotionRecordingUnits(MRUs)primarilyusedforthedynamicpositioningsystemofthevessel.

TheMRUislocatedtowardsthecentreofthevesselorbargeandthemovementatthecranetip(heave,heavevelocityandheaveacceleration)iscalculated.The

Operational Criteria Offers Increased Weather Window for Deployment

softwareanalysesthestatisticaldataofthemotionduringaspecifiedperiod(30minutesapprox.)andperformsaspectralanalysisofthedata.

Inordertoverifythemodel,themotionofthestructurebeingloweredisalsoprocessedinthesamemannerasthevesselorbargemotion.ThustheDynamicAmplificationFactoriscalculatedinrealtimeandcanbecomparedtoamodelsuchasthosedescribedinDNV-RP-103.

Thistechnologymaythereforeincreasetheweatherwindowforinstallationandeliminatestheuncertaintyinthecablebehaviour.

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DEEP7 May 2011

A new dimensionThe availability of information on the web has given Geographic Information Systems a new dimension.

GeographicInformationSystemsorganisedatainsuchawaythattheend-usercangaindirectaccesstoalltherelevantinformationrelativetoasubseastructureorcomponent,byclickingtoitssetpositiononadiagramormap.Informationavailableincludesgeoscience,designandengineeringdata,installationandoperationsdata,aswellassurveyandinspectiondata.Subsea7hasdevelopedanewonlineapplicationthatallowsthecombinationof“historical”datawith“live”informationavailable,whichalsohastheabilitytosupportforecasting.

Theonlinebenefitsarewide:

• Consistencyandbuild-upofthedataduringthecourseofafielddevelopmentproject,fromdesigntoas-built

• Readinessanddistributionofinformationduringtheoperation

• Accuracyandtraceabilityofas-builtdata

• ReliabilityoftheinputdataforLife-of-FieldandIMRactivities.

Thisnewweb-basedGeographicInformationSystemsserviceisalreadyoperationalonvariousFieldDevelopmentandLife-of-Fieldprojects.Itisprogressivelyexpandingwithbespokeapplicationsacrossprojects,disciplines,departmentsandregions.Thisispartofthecompany’sgrowingportfolioofGISservices,managedbytheLife-of-FieldGroupwithinSubsea7.

Reeled Clad SCR Weld Fatigue QualificationSteel Catenary Risers (SCRs) have been an attractive cost-effective choice for deepwater field development. One of the major design and fabrication challenges for SCRs is the achievement of the required fatigue performance at highly stressed regions. Additionally, the need for the transmission of corrosive constituents has demanded the use of corrosion resistant alloy line-pipe materials.

Todate,themostattractivepipematerialoptionforhighfatigueSCRs,istheuseofmetallurgicallybondedcladpipe.InstallationofsuchSCRsbythereel-laymethodisacosteffectiveapproach.Uptothepresenttime,reel-layinstallationhasbeenlimitedtocarbonsteelSCRs.ThelackoffatiguetestdatatodemonstratethesuitabilityofinstallationofcladSCRsbythereel-laymethodhasimpededtheutilisationofthistechnique.

Giventhehighlevelofindustryinterest,aqualificationprojectwascarriedoutbySubsea7incollaborationwithtwomajoroperators.TheoverallaimwastodevelopandqualifyasuitableweldingprocedureforinternallycladpipeforSCRserviceandtodemonstratethattherequiredfatiguelifecouldbeachievedafterinstallationbythereel-laymethod.

Thefourprimarycriteriathatwouldverifythesuitabilityofreelingincluded:

• Confirmbymechanicalandcorrosiontestingthatthegirthweldsmadeinalloy825cladpipemeettherelevantindustrystandards

• Confirmbyphysicaltestingthatsuchgirthweldsarereelable

• AutomatedUltrasonicTesting(AUT)verification

• ConfirmthatthefatigueperformanceofweldsmadeincladpipethathavebeenreeledwillmeetorexceedthetargetlevelsoffatigueClassC/2

Forthisspecificqualificationprogramme,materialGrade415(whichalsometGradeX65specificationrequirements)wasidentified,withanAlloy825metallurgicallybondedliner.Thenominalpipedimensionswere263.5mmIDx21.5mmWTand3mmcladlayer.

Attheprojectoutset,Subsea7proposedaweldingsolutionbasedontheuseofthemechanisedHotWirePulsedGasTungstenArcWelding(PGTAW)processandAlloy625fillerwireforthegirthweldingofcladpipe.SuchprocedureshavebeenpreviouslyqualifiedandsuccessfullyappliedfortheSkarvFlowlineprojectinNorway.Subsea7alsohadprevioussuccessfulexperienceintheuseoftheHotWirePGTAWprocessfortheweldingofcarbonsteelSCRsnamely,BC-10,BrazilandBlindFaith,GulfofMexicoprojects.

ThequalificationprogrammewasperformedingeneralaccordancewiththerequirementsofDNVOSF101-2007andtypicalindustrySCRspecifications.Allstandard

mechanicaltestsmetthespecificationrequirements.Fracturetoughnesstesting,bothweldmetalandfusionline,wasperformedinordertodemonstratetheachievementofadequatefractureresistanceinthegirthweldsduringpipelineinstallationandinsubsequentservice,whilstmaintainingrealisticwelddefectacceptancelevels.Thetestresultsshowedvaluesconsistentwithexpectedgoodbehaviour.CorrosiontestingwasperformedtoassessbothresistancetopittingcorrosionandtosulphidestresscorrosioncrackingandthesemetSCRprojectspecificrequirements.

TheprimarymethodofNDEforthegirthweldsincladpipewasAUTusingamultiphasedigitalpulseechotechnique.Theweldacceptancecriteriawerebasedonatypicalriserspecification.ValidationoftheAUTprocedurewasperformedusingrepresentativebutdeliberatelydefectivegirthwelds.Thisdemonstratedthatplanarflawsofconcerncouldbereliablydetectedandsized.

Cladpipestringscomprisingrepresentativebuttweldswerethenmanufacturedandinspected.TheseweresubjectedtoafullscalesimulatedreelingandinstallationprocedurewhichwasrepresentativeofpipelineinstallationbytheSeven Oceans reel-layvessel.Thesebuttweldsweresubsequentlysubjecttofullscalefatiguetestingusingthehighfrequencyresonancetestingtechnique.Thefatigueperformancefarexceededexpectations,withmosttestsamplesfailingintheparentmaterialwithfatiguelevelsclosetotheClassBmeancurve.

ThisqualificationprogrammegivesconfidencethatthefatigueperformanceofreeledcladpipesatisfiestherequirementsofSCRapplicationswithasignificantsafetyfactor.Furthermore,allotherSCRrequirementsintermsofweldintegrity,mechanicalandcorrosionperformancewerealsocomfortablyachieved. Weld Macro

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TheSeven Atlantic,oneoftheworld’snewest,mosttechnicallyadvancedandcapabledivingsupportvesselsandtheNormand Subsea,anInspection,MaintenanceandRepairvessel,equippedwiththelatestROVtechnology,havepredominantlybeensupportingtheShellUnderwaterServicescontractacrossEurope,inadditiontoundertakingseveralworkscopesforotherNorthSeaclients.Oneyearon,thenewbuildvesselsarelivingupto,andinsomecasesexceedingoperationalexpectations.

Diving support Stability, Performance & SpeedTheSeven Atlantichasprovedhersuperiorstationkeepingperformanceanddemonstratedthatshecanoperatecomfortablyinextremeweatherconditions.Thevessel’sstabilitysignificantlyreducesdependencyonportcallsforcrewchangeandasanexampleinApril2010,helicoptercrewchangesof38personnelweresafelyconductedinForce7conditions.Thevesselhasprovedshecanoperateateaseinfullydevelopedseaconditionsinexcessof4.5mHswithtransitspeedsofupto15knots.

Endurance & Capacity

Astheintegratedchemicaltreatmenttanksandequipmentarelocatedbelowdeck,the1200m2offreedeckhavebeenfrequentlyutilisedforsubseaprojectfacilities.Asanexample,afullriserinstallationcampaignacross4jacketswasexecutedinone30daytriplastsummer.Beingabletocarrytheentireinstallationpackageandsupportfull24hrairandsatdivingteamswithinthe150personnelon-boardcapacity,deliveredaseamlessresultfortheclient.

Diving & ROV System Versatility

CoveringShell’sassetsfromtheSouthernNorthSeathroughtotheNorthernNorthSeameansdepthtransitionsfromsurfaceto165m.Withher24-mansaturationsystem,theSeven Atlantic hasbeenabletoavoiddelaysthroughdecompression.Similarly,havingduplicatedair,sat,hoopandequipmentdeploymentsystemsonbothsidesofthevesselandumbilicallengthsgreaterthan

conventionalDSVs,meansshehasbeenabletomitigatetheconstraintsofplatformoverhangsandrestrictedaccessthroughouttheyear.

Sometimesswitchingbetweenoperatorshasmeantasignificantchangeindepth.TheSeven Atlanticsaturationsystemversatilityandcapacityhasenableddivingcrewstomakethesedepthtransitionswithout

decompressiondelaystojobs,thereforeavoidinglosttime.

TheSeven Atlantichassurpassedherdesignobjectivesandhasjustcompletedher1000thdive.Overthelast12monthsshehasreceivedanumberofclientcommendationswhichistestimonytoanexemplarydesignandacommittedteam,bothonshoreandoffshore.Shehasalsoachieved1yearLTIfreeinMarch2011.

Seven Atlantic and Normand Subsea - One Year On

“HavingbeeninvolvedintheSeven Atlanticfromtheconceptthroughtothebuildstageithasbeenincrediblysatisfyingtofollowherprogressinherfirstyearofoperations.Mostimportantlyithasbeentremendoustoseethevesselcompleteherfirstyearofoperationswithoutsufferinganylosttimeinjuries.SheisalargecomplexnewvesselandthissuccesshasonlycomeaboutthroughalotofhardworkandcommitmentfromtheVesselOffshoreManagementTeamandhercrew.ShellsetthebarhighintermsoftheoperationalrequirementsforthevesselandshehasnotonlymetalloftheirexpectationsbutonmanyoccasionsexceededthemthusestablishingatremendousreputationintheNorthSeamarket.” Steph McNeill, Subsea 7 UK VP

Fitted with a computer based control system providing automation of life support equipment and the hyperbaric environment, including depth control

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The Normand Subsea, Inspection, Maintenance & Repair

ThevesselisequippedwithsixROVs(twoworkclassHerculesandfoureyeballCougars)thathavesuccessfullyoperatedsimultaneouslyduringinspectionwork,whereeachindividualROVcanbeconfiguredtoconductdifferenttasksandbelaunchedasrequired,significantlyincreasingefficienciesanddecreasingvesseltimeattheworksite.AllsixROVsarecontainedwithintheconfinesandprotectionofthehangar,fouroftheROVsystemsaremoonpooldeployedwithtwoeyeballCougarsdeployedovertheportside.

TheModuleHandlingSystem(MHS)hasbeensuccessfullyusedonmanyoccasions,completingchokeandsubseacontrolmodulechange-outsintheharshenvironmentsoftheDraugenandOrmenLangefieldsintheNorwegiansectoroftheNorthSea.TheMHShasalsobeenusedfordeploymentoperations,whereweatherconditionshavepreventedcraneoperationscontinuing,againincreasingefficienciesanddecreasingweatherdowntime.

TheintegralwelltreatmentplantwasusedforthefirsttimetocompleteascalesqueezeoperationintheBitternfieldintheUKsectoroftheNorthSea.AnewROVfriendlyinterfaceunitwasspecificallydesignedforthetreeconnectionsandfollowingsuccessfuloperationsatBittern,theunitisbeingdevelopedandinstalledonfurtherwells.Previousscalesqueezeoperationshaverequiredafullspreadofequipmenttobemobilisedonthebackdeck.TheNormand Subseaavoidsthisbyhavingthetanksandmixingequipmentalreadybuiltinbelowdeck.

TheNormand SubseahascompletedTree-On-Wireoperations,atechniquewhereChristmastreesareinstalledusinganoffshoresupportvessel,ratherthanfromaDynamicallyPositioneddrillship.ThetechniquewasfirstcarriedoutintheNorthSeabySubsea7forShellin2009,bytheSkandi Seven.Thislessexpensivemethodisaquickerandmoreflexiblesolution,reducingtimebetweeninstallationandcommissioningandmostimportantly,freeingupvaluabletimeforthedrillship.

HighspecificationpipelineOutofStraightnessandhighresolutionroutesurveyswerecompletedontheOrmenLangepipelinesandfutureroutes,utilisingacomplexsuiteofequipmentnotpreviouslyusedbySubsea7.Againanotherfirstforthevessel,completedwithexcellentresults/dataproduced.

ThevesselalsocontinuestooperateastheprimarysubseainterventionvesselforOrmenLangeandDraugen.

Theperformanceandstationkeepinghavebeenexcellent,withthevesselprovingtobeanextremelystablework

“TheperformanceofboththeSeven AtlanticandtheNormand Subseahasprovedtobefantasticafteroveroneyearofoperation.Thesuccessofourjointventuresiswhollyattributabletotheprofessionalapproachofourpersonnel,notjustoffshoreonthevessels,butalsoonshoreintheofficewithallthepreparatoryworksthatgointothejobsthatwedo.

Whilstwecannotbecomplacentaboutouractivities,theterrificsafetyperformanceonbothvesselsisnoaccidentandistestimonytothepeopleandtheircultureandbehaviourswhenitcomestoconductingouroperations.

Ithasbeenhugelyrewardingtoseethesaferesponsesandperformanceachievedonmanyextremelychallengingworkscopesanddemandingschedules.

Aswelookforwardtofurtherdemandsinthecomingyears,Iamconfidentthatwiththevesselsandteamsinplace,wewillcontinuetoseeevermoreefficienciesandimprovementsinourcombinedactivities.”

George Thomson, Team Lead - Underwater Vessel Operations, Shell U.K. Limited

“TheNormand SubseaisnowwellintohersecondyearofserviceandhasbeenequallysuccessfulworkingcontinuouslyandmoreimportantlysafelyforShellintheharshestofenvironments.ThevesseliscriticalinkeepingtheOrmenLangegasfieldoperationalwhichisofstrategicimportancetotheUKasitprovidesupto20%ofourgas.WhileIamsureshewouldbewellusedbyourotherClientsshehasbeenfullyutilisedbyShellanddoesnotlooklikeshewillhaveanysparedaysforalongtimetocome.TogetherwithourpartnersSolstadwesetouttocreateanewclassofROVconstructionvesselandtheNormandSubseacertainlyticksthebox.”

Steph McNeill, Subsea 7 UK VP

platform.WithallROVandMHSbeingcompletedfrominsidethehangar,thecrewhasbeenunawareofjusthowpoorweatherconditionshavebeen,provinghowstablethevesselis.

A truly multipurpose vessel.

www.subsea7.comDEEP7 May 2011©Subsea7,2011.Informationcorrectattimeofgoingtopress.

DNV Qualification for Electrically Heated Pipe-in-Pipe

Thefollowingistypicaloftheanalysesandtestingcarriedout.

• Reelingtrialsandmonitoringofstrain

• FEAanalyses

• Thermaltestingonfull-scalepipe-in-pipesamples(pre&postreelinginpassiveandactivemode)

• Acceleratedwireageingshowingfeasibilityofcontinuous25-yearoperation

•Wiringconnectionandinterfacing

• Powerfeedandinterfacing.

Additionalconsiderations:•Methodstatementsforonshoreconstructionandoffshoreinstallation

• Identificationofkeyfabricationsteps

• Developmentofrelevantinspectionandtestingprocedures.

A key aspect in many new deeper and more challenging subsea developments is maintaining the appropriate product temperature within the pipeline infrastructure to avoid the formation of hydrates or waxing which would result in restriction to flow and potential complete shutdown.

Tohelpaddressthis,Subsea7haspartneredwithITPInTerPipe(ITP)tocommercialisetheElectricallyTraceHeatedFlowline(ETHF)pipe-in-pipesystemdevelopedbyITP.

Thetechnologycombinesthebestavailablethermalinsulationsystemonthemarketwithlow-powerresistiveheatingelements.Innormaloperation,thesystemprovides“no-touch”timesof72hoursormore,beforeheatingneedstobeswitchedon.5-10kW/kmisenoughforhydratemitigation.

Theadvantagesforoperatorsinclude:

• Tie-backsofunlimitedlength

• Shutdownsofunlimitedduration

• Safeproductionofreservoirtails

• Safeproductiongellingorhigh-viscosityfluids.

ThequalificationofthenewtechnologywasrecentlyconductedinaccordancewithDNVRP–A203“QualificationProcedureforNewTechnology”.The

technologywentthrougharigorousreviewprocessculminatingintheissueofDNV’sCertificateofFitness-for-Service.

ThetechnologyqualificationofthereeledETHFpipe-in-pipesystemwascompletedintwostages.

Firstly,thesystemwasqualifiedinpassivemode(withoutheatingelements),andsubsequentqualificationofthecompleteETHFsystemwithheatingwiresfollowed.Thetwosystemscombinedofferahighlyefficientmeansofmaintainingproducttemperatureintoday’schallengingsubseaenvironments.

Insulation

Production Pipe

Heating wires

Outer Pipe

ThetieredreviewprocesswithfrequentinteractionsbetweenSubsea7,ITPandDNVensuresearlyidentificationandresolutionofanygapsinthetechnologyqualification.

ThequalificationofthecombinedETHFpipe-in-pipetechnologyincludedtechnicalanalysesandtestingor,acombinationofthetwo.

TheDNVRP-A203isathree-stagequalificationprocessfocussingheavilyonthenewandunprovenelements.Thegatedapproachidentifies:

• Stage1Feasibility

• Stage2Endorsement

• Stage3FitforService

Insulation being applied to inner pipe over trace heating wires