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Chapter1OilandGasFields第1章油气田1.1AnIntroductiontoOilandGasProduction1.1石油和天然气生产的介绍Thecomplexnatureofwellstreamsisresponsibleforthecomplexprocessingoftheproducedfluids(gas,oil，water,andsolids).Thehydrocarbonportionmustbeseparatedintoproductsthatcanbestoredand/ortransported.Thenonhydrocarboncontaminantsmustberemovedasmuchasfeasibletomeetstorage,transport,reinjection,anddisposalspecifications.Ultimatedisposalofthevariouswastestreamsdependsonfactorssuchasthelocationofthefieldandtheapplicableenvironmentalregulations.Theoverridingcriterionforproductselection,construction,andoperationdecisionsiseconomics.油气井井流的复杂性质，决定了所产流体(气、油、水和固体)的加工十分复杂。必须分出井流中的烃类，使之成为能储存和/或能输送的各种产品;必须尽可能地脱除井流中的非烃杂质，以满足储存、输送、回注和排放的规范。各类废弃物的最终处置取决于各种因素，如油气田所处地域和所采用的环保规定等。经济性是决定油气田产品设计、建筑和操作决策的最重要准则。Fig.1-1isacomprehensivepictureoftheindividualunitoperationscarriedoutinfieldprocessing.Allthevariousmodulesshownwillnotallbepresentineverysystem.Furthermore,themodulesusedinagivenapplicationmaynotbearrangedintheexactsequenceshown,althoughthesequenceis，ingeneral,correct.Theselectionandsequencingofmodulesisdeterminedduringthedesignphaseoffielddevelopment.图1-1表示在矿场进行的各种单元操作的综合图。在各系统内不一定有图1--}所示的全部操作模块。尽管图中所示的加工顺序通常是正确的，但在某一特定使用情况下，模块的布置可能会与图中所示的顺序不同。在油气田开发设计阶段确定模块的选择和排列顺序。AsshowninFig.1-1，theindividualphases(gas，liquidhydrocarbon,liquidwater,andsolids)shouldbeseparatedfromeachotherasearlyaspractical.Individualstreamscanthenbetreatedwithlesstechnicaldifficultyandmoreeconomically.HartleyandBinJadid(1989)illustratehowlabandfieldtestsperformedbeforeconstructioncanidentifyandminimizefutureproductionandprocessingproblemssuchasscaling,foaming,emulsionformation,waxdeposition,andhydrateformation.Processingoftheseparatedstreamsisnowreviewedbrieflybecausemanyoftheindividualunitoperationsarediscussedindetailinsubsequentchapters.如图1-1所示，应尽早将各股流体(气、液态烃、液态水和固体)分离。这样，单独处理各股流体时，技术难度较小，也较经济。Hartley和BinJadid(19$9阐明了在建设前进行的室内和现场试验可以发现并减少将来在生产和加工中可能出现的问题，如结垢、发泡、形成乳状液、结蜡以及生成水合物等,现在简要介绍被分离的各股流体的加工，在后续章节中将详细讨论其中的许多单元操作。1.1.1GasProcessing1.1.1气体加工AsshowninFig.1-1，gasprocessingbeginswithtreating,ifnecessary,toremovetheacidgases-hydrogensulfideandcarbondioxide.Bothgasesareverycorrosivewhenliquidwaterispresentandhydrogensulfideismosttoxic.Environmentalregulationsalmostalwaysprohibitthereleaseofsignificantamountsofhydrogensulfidetothesurroundings.Conversiontoelementalsulfurisbecomingincreasinglynecessary.如图1-Z所示，气体加工(若需要)从脱除酸气(H2S和CO2)开始。当存在液态水时，这两种气体有极强的腐蚀性,而且H2S极具毒性。环保法规几乎都禁止向周围环境排放大量H2S，而且正愈来愈多地要求将H2S转变为元素硫。Gassweeteningusuallyusesaqueoussolutionsofvariouschemicals.Therefore,sweeteningwillprecededehydration.Dehydrationisoftennecessarytopreventtheformationofgashydrates,whichmayplughigh-pressureprocessingequipmentorpipelinesathighpressureandattemperaturesconsiderablyhigherthan32°F(0°C).天然气脱酸气常使用各种化学剂的水溶液，因而脱酸气应在气体脱水之前进行。为防止生成气体水合物，常需进行脱水。在高压和比32°F(0℃)高的温度下，水合物可能堵塞高压工艺设备和管线。Gasthatcontainsconsiderableamountsofliquefiablehydrocarbons(ethaneorpropaneandheavier)canproducecondensateuponcompressingorcooling.Thecondensatemaycausedifficultyinpipeliningorsubsequentprocessing.Fieldprocessingtoremovethesenatural-gasliquids(NGL),sometimesreferredtosimplyascondensate,maybeeconomicalormayberequiredtomeetahydrocarbondew-pointspecification.Inremotelocationssuchprocessingisgenerallyavoidedifpossible.Recoveredcondensatemay,inturn,havetobestabilizedbyremovingdissolvedgaseouscomponentstoobtainatransportableproduct.含有大量可液化烃类(C2+或C3+)的气体，在压缩或冷却时一可能产生凝析油。凝析油会给管输和后续加一带来困难。在矿场脱除这些天然气液体(NGL,有时简称为凝析油)可能是经济的，或为满足烃露点规定所必需的。在边远地区应尽一量避免脱除凝析油的工作。回收的凝析油必须进行稳定，脱除溶解气组分，以获得可输送的产品。1.1.2OilProcessing1.1.2原油加工Afterfreewaterremoval,producedoiloftencontainsexcessiveresidualemulsifiedwater。].Treating,alsocalleddehydration,isrequiredtoreducethewatercontenttoavalueacceptablefortransportationorsales.Dehydrationshouldbeaccomplishedusingthemosteconomiccombinationoffourfactorsortechniques;namely,residencetime,chemicaladdition,heat,andelectrostaticfields.Dilutionwatermustoccasionallybeaddedtoreducethesaltcontentoftheresidualemulsion(i.e.,thesalescrudeoil)toasuitablylowlevel.IntheUnitedStates，desaltingisusuallyperformedintherefinery；overseas，desaltingissometimesperformedinthefield.脱除游离水后，生产的原油内常含有过量的残余乳化水。含有过量残余乳化水的原油需要进行处理(也称脱水)，将水含量降至运输和销售允许的限度内。可应用四种技术的最经济组合实施脱水，即停留时间、化学添加剂、加热和静电场。有时还必须掺人稀释水，将残余乳状液(即销售原油)内的盐含量降低至合理的低浓度。美国，脱盐常在炼厂进行；美国以外地区，脱盐有时在矿场进行。Hydrogensulfideincrudeoilislimitedtoreducehandlingandtransportationdifficultiesbecauseofitsextremetoxicityandcorrosiveness.Gasstrippingorheatingisusuallyusedforhydrogensulfideremovalorsweeteningasisdiscussedlatterly.由于H2S具有剧毒和腐蚀性，故应限制原油内H2S的含量，以降低原油装卸、沛在和输送过程的困难。如在后续内容中讨论的那样，常用气提或加热方法脱除原油内的H2S，或使其“甜化”。Crudeoilstabilizationreferstoloweringthevaporpressuretoavaluethatwillallowsafehandlingandtransport.Vaporpressurecontrolisobtainedbystageseparation,reboileddistillation,oracombinationofthetwo.Duringstabilizationsomeofthemorevolatilehydrocarbonsareremovedasvaporandthisgasphaseentrainshydrogensulfideandothervolatilesulfurcompoundsfromthesourcrudeoil.Additionalsweeteningmaynotberequired.原油稳定是