石油工程雙語版課件07生產(chǎn)工程

生產(chǎn)工程

ProductionEngineeringProduction

(FundamentalsofPetroleum,UT-Austin,P.135-)生產(chǎn)工程(Definitionofproduction)（1）將地層的流體（油或氣）由井底帶到地表。

(bringthewellfluidtosurface)（2）將地表的流體作處理（例如:油氣分離），以作為輸送到煉油廠之前的準備。

(preparingthemfortheirtripthroughthepipelinetotherefinery)生產(chǎn)之階段（Stages或phases）（1）完井（completethewell）--bringthefluidtothesurfaceThefirststepistocompletethewell－thatis,toperformwhateveroperationsarenecessarytostartthewellfluidsflowingtothesurface（2）例行修護（Routinemaintenanceoperations）--doingwhateverisnecessarytokeepthewellproducing

（a）修復(fù)磨損及malfunctioning的設(shè)備--replacingwornormalfunctioningequipment,arestandardduringthewell'sproductionlift,and

（b）Workover--moreextensiverepairs,knownasworkovers,maybenecessarytomaintaintheflowofoilandgas（3）流體分離（Separatethefluids)--takingthefluidsthroughaseriesofstepstopurify,test,andmeasurethemThefluidmustbeseparatedintoitscomponents,becausewellfluidareusuallyamixtureofoil,gas,andwater.Thesemustbetreated,measure,andtestedbeforetheyareruntothepipelineontheirwaytotherefineryWellcompletion(完井)Afterawellhasbeendrilledtotheprojecteddepthandtheproductiveformationhavebeenevaluatedfortheireconomicworthandprofit,workwillbeginto（1）setcasing(下套管)（2）preparewellforproduction(準備生產(chǎn))（3）bringinthezoneorzones(生產(chǎn))

WellCompletionCompletionequipmentandthemethodsemployedarequitevaried,andthedecisionsforanindividualwellareusuallybasedon

－thetypeofoilorgasaccumulationsinvolved,

－therequirementsthatmaydevelopduringthelifeofthewell,and

－theeconomiccircumstancesatthetimewhentheworkisdone.WellCompletionLowpressure,sometimessecondhandpipewillbeemployediftheoilaccumulationhasamarginalpayout,andotherexpenditureswillbescaleddownaccordingly.Ifhighpressureisanticipatedandwelllifeisexpectedtobelong,however,thebestgradeofpipewithbackupprecautionswillbeneeded.ThewellTypically,anoilorgaswellwillrequirethreeconcentricstringsoflargepipe:

－conductorpipe,

－surfacecasing(~500’-5000’),

－oil–stringcasing,and--tubing（1）ConductorpipeTheconductorpipepreventstheholefromcavinginatthesurfaceareendangeringthedrillingrigfoundation.Itisusuallycemented,butoccasionallyitisdrivenintoplacebyapiledriver.（2）Surfacecasing

Whenthesurfacecasingissetandcementedinplace,itprovidesprotectionforfreshwaterformations.Italsopreventslooseshaleandsandorgravelfromfallingintotheholeandaffordsameansforcontrollingtheflowoffluidfromthewell.Settingdepthsmayvaryfrom500ftto5000ft.（3）Oilstring,orlongstring

－Thefinalcasingformostwellsistheoilstring,orlongstring.－Theproducingformationisusuallycompletelycasedoff,butsometimestheoilstringissetnearjustorontopofthepotentialpayzone.Tubing

－Thefinalstringofpipeusuallyruninaproducingwellisthetubing.－Tubingisnearlyalwaysfreelysuspendedinthewellfromthecasinghead.－Advantageofputtingatubing（a）It'ssmalldiameterproducesmoreefficientresultsthancasinginaflowingwell.（b）Tubingalsomakesasaferwellcompletionpossible.（c）Tubingiscomparativelyeasytoremovewhenitbecomespluggedordamaged.（d）Tubing,inconjunctionwithapacker,keepswellfluidsawayfromthecasingbecausethepackersealsthespacebetweenthetubingandcasing.Casing,tubing,andpackerarrangementinaflowingwellTheWellheadThewellheadismadeupofacombinationofpartscalled---Casinghead---Tubinghead---Christmastree--Stuffingbox,--Pressuregauges

TheWellhead─Thewellheadistheequipmentusedtomaintainsurfacecontrolofthewell.─Itformsasealtopreventwellfluidsfromblowingorleakingatthesurface.─Theconditionsexpectedtobeencounteredintheindividualwelldeterminethetypeofwellheadthatisneeded.─Sometimes,allthatisrequiredisasimpleassemblytosupporttheweightofthetubinginthewell.─Inothercases,thecontrolofformationpressuresisnecessary,andahigh-pressurewellheadisrequired.Thewellhead(井頭)SurfacecontrolPreventwellfluidfromblowingorleakingSupporttheweightofthetubingControlofformationpressure（1）Casinghead─Thecasingheadisaheavysteelfittingatthesurfacetowhichthecasingisattached.─Itprovidesahousingfortheequipmentfromwhichintermediatestringsofcasingaresuspended.─Duringdrillingandworkoveroperations,thecasingheadisusedasananchorforthepressure-controlequipmentthatmaybenecessary.（2）Tubinghead─Similarindesignandusetothecasinghead,thetubingheadsupportsthetubingstring,sealsoffpressuresbetweenthecasingandtheinsideoftubing,andprovidesconnectionsatthesurfacewithwhichtheflowingliquidorgascanbecontrolled.─Thetubingheadissupportedbythecasingheadifacasingheadisusedonthewell.（3）Christmastree─Thecontrolvalves,pressuregauges,andchokesassembledatthetopofawelltocontroltheflowofoilandgasafterwellhasbeendrilledandcompletedareknownastheChristmastree,sonamedbecauseofitsshapeandthelargenumberoffittingsbranchingoutabovethewellhead(fig.5.4)─Thepressuregaugesrevealcasingandtubingpressures.Byknowingthesepressuresundervariousoperatingconditions,betterwellcontrolispossible.ChristmastreeCompletionmethodsAwell-servicingcontractormaymoveinasmallerrigtoperformtheoperationsnecessarytoputthewellinproduction.─Thetypeofcompletionmethodusedisdeterminedbythecharacteristicsofthereservoiranditeconomicpotential.─Amongthevarioustypesofcompletionmethodsusedareopen-holeandlinercompletions,perforating,andswabbing.Wellcompletions－completionmethodsCasingCompletions

－Conventionalperforatedcasingcompletions

－Multiple-zonecompletions

－Waterandgas–exclusioncompletions

－

Sandexclusioncompletion(gravelpackingcompletion)Open–holecompletionsorbarefootcompletionsDrainholecompletionsOpen-holeandlinercompletions─Inanopen-hole,orbarefootcompletion,noproductioncasingorlinerissetoppositetheproductionformation(fig5.5).Reservoirfluidsflowunrestrictedintotheopenwellbore.Thistypeofcompletionmethodhaslimiteduseincertainsituations.

─Inthelinercompletion,ascreenlinerisusedtoobtaincommunicationbetweenthereservoirandthewellbore.Fig5.5Open-holecompletion

orbarefootcompletions

Perforating─Perforatingistheprocessofpiercingthecasingwallandthecementtoprovideholesthroughwhichformationfluidsmayenter.─Perforationshould(a)provideaclean,undamaged,andproductiveperforation,(b)penetratetheproducingintervalasfaraspossible,(c)shootasmoothandroundentranceholeinthecasing(d)produceminimalcasingandcementdamage,and(e)producethemaximumflowratewiththeminimumnumberofperforations.─Twobasicmethodsofpiercingthecasingwallarebulletperforatingandjetperforating.BulletPerforatingBulletPerforatorareloweredintotheholeandfiredelectricallyfromthesurface.(fig5.6)Bulletscauselittlecasingdamageandlessdamagetothecementsheathbetweenthepipeandwalloftheholethanjetchange.BulletperforationJetperforatingInjetperforating,shaped-changeexplosivesareemployedinsteadofbullets.JetperforatingBulletperforationismoreeffectiveinformationoflowtomoderatecompressivestrength,whilejetperforationisgenerallybetterinrockwithhighcompressivestrength.Amuchsaferwellcompletiontechniqueistomaketheperforationsafterthetubinghasbeenrunandthepackersetbecausethewellisunderabsolutecontrolatalltimes.Thru-tubingperforationhasbeenmadepossiblebythedevelopmentofperforatingdevicessmallenoughtorunthroughtubing.SwabbingSwabbingisatemporaryoperationthatlowerthefluidlevelinthewellsothatitcanbegintoproduceIfenoughfluidcanbeswabbed(lifted)outofthetubingsothatthepressureintheformationisslightlygreaterthanthehydrostaticpressureofthefluidinthetubing,theoilorgaswillstartflowingimmediatelyaftertheperforationaremade.Ifthefluiddoesnotflowafterbringswabbed,apumpisinstalledasapermanentliftingdevicetobringtheoilthesurface.WellServicingandWorkoverWellServicing定義－themaintenanceworkperformedonanoilorgaswelltoImproveormaintainfromaformationalreadyproducing.Themostcommonwell-servicingoperationsarethoserelatedto

（a）artificial-liftinstallations,（b）tubing-stringrepair,and（c）workonotherdownholeequipmentthatmaybemalfunctioningWellservicingandworkoverWellservicing

Awell-servicingunitcarriesthehoistmachinerythatisusedtopullsuckerrods,anoperationthatisdonemostfrequentlyforpumpchangesorrod-stringrepairs(fig5.8p.144)Fig.5.8Truck-mountedwell-servicingunitWellservicingThesameunitcanbeusedtopulltubingbyarrangingtheequipmentfortheheavierload.Themostcommonwell-servicingoperationsarerelatedto(a)artificial-liftinstallations,

－sucker-rodpump,orRodpumporbeampump.

－gaslift,

－h(huán)ydraulicpump

－submersiblepump(b)tubing-stringrepairs,and(c)workonotherdownholeequipmentthatmaybemalfunctioning.Workover

Likewellservicing,thepurposeofaworkoveristoincreaseproductionofaproducingwell,butworkoversincludemoreextensiverepairs.Workoverrigs,inmanyrespects,arescaled-downdrillingrigs(fig.5.9).Theyareequippedtostandthepipeinthederrick,theyhavesomearrangementforturningthepipestringwhileitisinthehole,andtheyarefurnishedwithahigh-pressurepump.Fig5.9Self-propelledworkoverrigWorkoverThepumpisusedtocirculatefluidinthewell-thatis,toforcewaterorotherliquidinsidethetubingtothebottomofthewellbypumppressureandthenoutsidethetubingbacktothesurfaceintoatanktocompletethecircuit.Aworkoverincludesanyworkperformed(a)tochangetheproducingzoneinawell(b)tocleanout,or(c)toreachanoldproducingintervalArtificialliftWhenawellisfirstcompleted,thefluidisexpectedtoflowtothesurfacebynaturalreservoirenergyforsomeperiodoftime.Atsometimeduringtheireconomiclife,however,mostoilwellswillrequiresomeformofartificiallifttohelpraisethefluidtothesurfaceandobtainthemaximumrecoveryofoilformaximumprofittotheproducerThemostcommonmethodsofartificialliftare:Gaslift,Sucker-rodpump,Hydraulicpump,andSubmersible(1)GasliftIfasupplyofgasiseconomicallyavailableandtheamountoffluidwilljustifytheexpense,gasliftiscommonlyused(fig.5.10;p146)Inthegas-liftprocess,gasisinjectedintothefluidcolumnofawelltolightenandraisethefluidbyexpansionofthegas.Injectedgasaeratesthefluidtomakeitexertlesspressurethantheformationdoes;consequently,thehighformationpressureforcesthefluidoutofthewellbore.Gasmaybeinjectedcontinuouslyorintermittently,dependingontheproducingcharacteristicsofthewellandthearrangementofthegas-liftequipment.Fig5.10Principleofgaslift(2)Sucker-rodpumpsTheartificial-liftmethodthatinvolvessucker-rodpumpiscommonlyknownasrodpumping,orbeampumping.Surfaceequipmentusedinthismethodimpartsanup-and-downmotiontoasucker-rodstringthatisattachedtoapiston,orplunger,pumpsubmergedinthefluidofawell.Mostrod-pumpingunitshavethesamegeneraloperatingprinciples.(fig5.11;p147)Fig5.11Rod-pumpingcomponents(3)HydraulicpumpsHydraulicpumpsaresocalledbecausetheyareoperatedbyahydraulicmotorintheunitatthebottomofthewell.Thefluidusedtodrivethemotoristheoilfromthewellitself.Themotor,inturn,drivesapumpthatpumpstheoiltothesurface.Onetypeofhydraulicpumpisthefreepump.Thispumpisinstalledinthebottomofthetubingandisoperatedbyoiltakenfromatankatthesurfaceandpumpeddownwardthroughthetubing.Thepoweroilisreturnedtothesurfacethroughthesmalltubing,alongwithnewoiltakenfromtheformation.(4)SubmersiblepumpsThemotorandpumpingunitsareloweredintothewellonastringoftubing,andthepump.RoutinemaintenanceworkRoutinemaintenanceworkisneededthroughoutawell’slifeifeconomicalproductionistobemaintained.Pumppartswearoutandmustbereplacedperiodically,rodsbreakandmustberepaired,andgas-liftdevicesmustbereplacedoccasionally.Otherremedialworksneededtokeepawellonsteadyproductionmyincluderepairoftubingleaks,replacementofpackersthathavefailed,andsandcontrol(1)PartreplacementWellequipmentsuchas

downholepumps,suckerrods,gas-liftvalves,tubing,parker,andsoforthmustbeingoodworkingcondition.Rodpumpsultimatelywearoutbecauseofabrasiveorcorrosiveconditionsandtheirreciprocatingcharacteristic.Suckerrodsareoftenhighlystressedandmayultimatelyfailbecauseofrepeatedloadreversals.Corrosion,scale,andparaffindepositsmayacceleratesuchfailures.(1)PartreplacementTubing-androdsforthatmatter-willwearduetothereciprocatingmovementinthewellasthestringstretchesandunstretchestoadjusttothechangingfluidloadswhilepumping.Packersandotheraccessorydevicessometimesfailbecauseofthehydraulicandmechanicalloadsthatareimpressedonthem.(2)CleanoutandsandcontrolMajorcleanoutandworkoveroperationsincludeSandremoval,Linerremoval,Casingrepair,Drillingdeeper,orSidetrackingThesejobusuallyrequireastringofpipethatcanberotated.Also,itisgenerallynecessarytocirculatethewell-thatis,pumpfluidtothebottomandbacktothesurface.Usuallysaltwaterorspeciallypreparedcirculating,orworkover,fluidisused.(2)CleanoutandsandcontrolCirculatingthewell(a)removessand,cutting,orchips;(b)preventsblowoutbymaintainingadequatehydrostaticpressuretoovercomeformationpressure;(c)coolsbitsandcutters;(d)actuateshydraulictools,and(e)whereopenholeisinvolved,supportsthewalloftheholeuntilcasingorlinercanbeset.Thesefunctionsrequireasuitablecirculatingsystem,apump,hoseandswivel,stringofpipetobottom,andapitortanktoreceivefluidreturningfromthewell.

Productionmenhavetriedforahundredyearstodeviseamethodofkeepingsandoutofwell.

Menwhoworkinhard-rockcountrymayneverhavesandtrouble,butinCaliforniaandtheGulfCoastSandproblemsoccureverydayandarehandledalmostroutinely.LoosesandiscontrolledbyPlasticsqueeze,Gravelpack;Ascreenliner,orAcombinationofthesemethods.Plasticsqueezeinvolvesplacingaresinousmaterialintothesandformationandthenallowingtheplastictoharden.Inthegravel-packingprocess,gradedgravelisplacedoutsidethecasingorliner;thisgravelholdsbackthesandbutallowsthewellfluidstoenterthewellbore.Onetypeoflinerusedtocontrolsandisaslottedpipewiththeslotscuttransversely.Thelineralsoactstoadmitoiltothebottomofthewellandexcludesand.Whenproductionshowssand,itusuallyindicatesthatthelinerhasfailedandthatremedialworkisinorder.WellstimulationThetermwellstimulationencompassesprocessesusedtoenlargeoldchannel,ortocreatenewonesintheproducingformation.Sinceoilusuallyoccursintheporesorcracksofsandorlimestoneformations--andseldom,ifever,inanundergroundpoollikeatank--enlargingorcreatingnewchannelsmeansthattheoilorgaswillmorereadilytoawell.Threewell-stimulationmethodshavebeendeveloped:explosives,acidtreatment,andhydraulicfracturing.(1)ExplosivesUsinghighexplosivestoimproveawell’sproductioncapacitybeganinthelate1800sandcontinueduntilacidtreatmentandhydraulicfracturingweredevelopedinthe1940s.Therehasbeen,however,arevivalofinterestinexplosivefracturinginrecentyearsforthefollowingreasons:(a)certainkindsoftightformationsdonotrespondreadilytoeitheracidizingorhydraulicfracturing,(b)experiencehasshownthatmanyoftheolderwellsthatwereshotarestillproducingcommercially,whilewellsthatwerehydraulicallyfracturedoracidizedarenot.(c)moderntechniquesandexplosivematerialshavebeendevelopedtodoabetterandsaferjobthanhere-to-forpossible.55(1)Explosivestherearenowtwobasicwaysofusingexplosivesforformationstimulation:(a)toconcentratedetonationonlyintheborehole.(b)toinjecttheexplosiveawayfromthewellborefordisperseddetonationwithafracturesystem.Explosivefracturingsupposedlyenlargestheeffectivewellbore,eliminatesnearbyformationplugging,andattheinstantoftheexplosionfurnishesasourceofhigh-pressuregastoforcefluidintotheformationatinjectionratesequivalentto20tonsofwaterpersecond.theformationofrubblethatissaidtobeproducedbyexplosivesshouldpreventfracturehealing,makingtheuseofproppantsunnecessary.(2)AcidtreatmentAcidtreatmentawaybeappliedtobothnewandoldwells.Theprimarypurposeofthistypeofwellstimulationistodissolverock,thusenlargingexistingchannelsandopeningnewonetothewellbore.oil-fieldacidsmustcreatereactionproductsthataresoluble;otherwise,solidmaterialswouldbeprecipitatedandplugtheporespaceintherocks.58(2)AcidtreatmentTheacidmustalsoberelativelysafetohandle,andsincelargevolumesareused,itmustbefairlyinexpensive.

Reservoirrocksmostcommonlyacidizedarelimestone(calciumcarbonate)anddolomite,whichisamixtureofcalciumandmagnesiumcarbonates.Additivesareusedwithoil-fieldacidformanyreasons,butthemostimportantistopreventordelaycorrosion-thatis,toinhibittheacidfromattackingthetubingorcasinginthewell.(2)AcidtreatmentAsurfactant,orsurfaceactiveagent,isanothertypeofadditive.Itismixedinsmallamountswithanacidtomakeiteasiertopumpthemixtureintotherockformationandtopreventspentacidandoilfromformingemulsions.Othertypesofadditivesaresequesteringagentsandsuspendingagents.Mostlimestoneanddolomiteformationshavelowpermeabilities.Acidinjectionintotheselow-permeabilityformations,evenatmoderaterates,usuallyresultsinafracturetypeofacidtreatment,meaningthatthepressureishighenoughtocausetheformationtocrack.Thisismostwidelyusedtreatmentforwellstimulationwithacid.(2)AcidtreatmentAnothertypeoftreatment--interstitial,ormatrix,acidizing--alsoresultsinproductionincreases.Interstitialacidizingconsistsoftreatingatarateandpressurelowenoughtoavoidfracturingtheformation.Thistechniqueisusuallyused(a)whenformationdamageispresentor(b)whereawaterzoneorgascapisnearbyandfracturingmightresultinhighwaterorexcessivegasproduction.(3)Hydraul