Designphilosophy

Designphilosophy1.Crudeoilproduction,separationandtreatingTheGOMfacilityrequiredmoreequipmentforcrudeoilproduction,separationandtreatingduetothelowerwellproductivity,lowersurfaceflowingtemperatureandrequirementsforlowerRVPforsales.TheGOMdesignhadamanifoldallowingeachwelltobeproducedintoanyoneofthreestagesofbulkseparation,heating,electrostaticoiltreateranddry/wetoiltanks.TheNorthSeafacilityhadallwellsroutedtothefirststageseparator,nooiltreater,coolingforstabilization,asurgevesselbutnodryoiltank.2.GascompressionandtreatingGOMfacilityhadnoprovisionforloweringhydrocarbondewpoint.Itincludedatriethyleneglycolsystemdesignedfor7lb/MMSCFwatercontentinthesalesgas.TheNorthSeasystemincludedapropanerefrigerationsystemtochillthegasforbothwaterandhydrocarbondewpointcontrol.3.ProducedwatertreatmentanddisposalTheGOMfacilityincludedtwostagesofwatertreating(CPIandFlotation)whiletheNorthSeafacilityutilizedflashseparationandonestageofwatertreating(Flotation).4.WaterfloodsystemTheGOMfacilityutilizednaturalgasstrippingandcartridgefilters.TheNorthSeafacilityutilizedsandfiltrationandvacuumdegassing.5.PowergenerationInGOM,compressorsandpumpsgreaterthanapproximately500HPnormallyhavetheirownprimemover.Withthewaterfloodpumps,pipelinepumps,maincompressorandhighpressureboostercompressorallbeingdrivenbyturbineprimemovers,three850KWgeneratorsaresufficientforremainingelectricalload.TheNorthSeaphilosophyoperatedmotordrivenpumpsandprovidedalargecentralpowergenerationfacility.Two23megawattturbinegeneratorssetswereselectedforthisstudy.Nospareunitwasprovidedasthewaterfloodloadcanbeshedtemporarilywhileaunitisbeingserviced.6.ElectricalIntheGOMdesignControlcablesand480voltpowercablesareruntoeachmotorwhichisnotpartofamajorpackage.Thecompressors,waterfloodpumps,pipe1inepumpsandquarter’packageseachhaveonesetof480voltcablesruntothemwithindividualmotorstartersincludedintheircontrolpanels.Miscel1aneous,120voltand208voltbranchfeedersareusedforlighting,spaceheaters,etc.IntheNorthSeafacility,threevoltagelevelsareutilized.The11,000voltsystemfeedsthelargehorsepowermotorssuchasthe4,000HPwaterfloodpumpmotors,therefrigerationcompressormotorandthepipelinepumps.Theseawaterliftpumpmotorsarerunoffofthe3300voltsystemandtheremainingmotorsarerunoffofthe415voltsystem.7.InstrumentationGOMplatformhaslocalpneumaticprocesscontrolwithapneumaticshutdownsystem.Eachmajorpieceofequipmenthasalocalshutdownpanelwhichsendsandreceivessinglepneumaticsignalstoandfromthecentral.shut-downpanel.A12VDCcontrolprovidesamimicofthispanelinthequartersbuilding.Themainprimemoverseachhavetheirownlocalelectropneumaticpanelwhichprovidesforstart-upandshut-downsequencing,operationalcontrolandthesendingandreceivingofstatusandshutdownsignalstoandfromthecentralshut-downpanel.NorthSeainstrumentationisgenerallyelectronicwithRTUs(remoteterminalunits)andPLCs(programmablelogiccontrollers)forconstantmonitoring,andanalysisofplatforminformationinthemaincontrolroomandonshoreifdesired.Thistypeofcontrolsystemrequiresoverfortyinterconnectingcontrollogicunitsforvariousplatformpackagesystems.Eachmoduleisequippedwithplatformstatuslightsandapublicaddresssystemwithtelephonesfordirectcommunicationswithothermodulesorthemaincontrolroom.8.FireprotectionTheGu1fofMexicoplatformhasafirewaterloopsuppliedbyelectricmotordrivenseawaterpumps.Ithasnofixedspraysystemordieselpoweredfirewaterpump.IntheNorthSeafacilitytheprotectionsystemsforeachprocessmoduleconsistofwaterdeluge,fixedhosereelsandportablefireextinguishers.Fourdieselsdrivenfirepumpslocatedinpairsindifferentmodulesareprovided.FirewallsisolateprocessmodulesandtheHVACsystemisinterconnectedwiththefireprotectionsystem.9.HeatingandVentilationTheGu1fofMexicosystemhasopenmoduleswithnorequirementforheatingandventilation.InNorthSeadesign,twoseparateventilationsystemscompletelyisolatedfromoneanother.Onesystemoperatesunderaslightlynegativepressureintheprocessmodulesandtheotherunderaslightlypositivepressureinsafemodules.Thesystemsaredesignedforsixairchangesperhourandrequireabout2500fanhorsepowertoprovidethenecessaryventilation.