(石油地质及储油层)(1).ppt

1,Chapter2PetroleumGeologyandReservoirs石油地質及儲油層2008,References石油地質及儲油層PetroleumGeologyandReservoir,Textbook1FundamentalsofPetroleum,PetroleumExtensionService,TheUniversityofTexasatAustin,Austin,Texas,1979.–chapter1Textbook2Archer,J.S.,andWall,C.G.,PetroleumEngineeringprinciplesandpractice,Graham4.2,2,3,PetroleumGeology石油地質,Geology地質---研究1地球的歷史及構造2記錄在岩石的生物命形式PetroleumGeology石油地質---研究地質以預測石油累積之處所,4,地球的形成及構造,地球的形成40～50億年前由宇宙塵Cosmicdust的凝結而成地球內部大構造Core---heavy4,400milesMantle---Lighter1,800milesCrust---1030miles,5,地球內部大構造,,Core--heavy4,400milesMantle--Lighter1,800milesCrust---1030miles,6,地球表面的變化--Rockcycle,,,Magma岩漿,Igneousrocks火成岩,Sediments沉積物,Sedimentaryrocks,Metamorphicrocks,地球內部,Watervaporandgases,Prim初期的Atmosphere大氣,地殼冷卻,地殼收縮變形而皺摺,噴出,,形成,,,,,,,,,heat,heatpressure,erosion,erosion,pressurecementation,erosion,,,,,,下雨,,,Cool,7,沉積岩的分類,,8,ReservoirRockSedimentaryRock,,9,地球的歷史,寒武紀Cambrian【約5.5億年前】開始在海洋裡有大量的生物生命在寒武紀之前為前寒武紀Precambrian地質年代自寒武紀開始地質代年表GeologicTimeScale泥盆紀Devonian時期【約3.3億年前】陸上有大量植物及動物,10,GeologicalTimeScale,11,地層年代表,,12,,,13,Petroleumaccumulation石油累積Petroleumreservoir石油油藏;油藏;油層,Petroleumaccumulation必須具備1Oil＆gas之來源2具有孔隙porosity及滲透率permeability之ReservoirRock3要有trap封閉以阻擋流體的流動,14,石油的來源,15,石油的來源,－石油來自沈積岩的有機物質－海洋裡大量的生物不停的，緩慢的掉落到海底。雖然在掉落的過程中，有部分被吃掉或被氧化掉，但另部份動物或植物掉落海底而埋在沼澤或泥濘之海底－海底繼續被Sand砂，Clay黏土及debris等沈積物埋沒一直到幾千英呎－沈積物的壓力開始作用。細菌由殘餘的有機物質中，用掉氧而分解物質，使其僅存碳及氫－在高度的壓力及重量的地層影響之下，Clays變成Shales→石油產生,16,,Petroleumationrequiresthatorganicsourceclaysbecomematurebysubjectiontopressureandtemperature.,17,石油形成的重要條件,225℉500℉有機物質碳化，不能形成石油,18,Generationofgasandoil,,19,20,,Ingeologyandoceanography,diagenesisisanychemical,physical,orbiologicalchangeundergonebyasedimentafteritsinitialdepositionandduringandafteritslithification,exclusiveofsurfacealterationweatheringandmetamorphism.,21,,CatagenesiscanrefertoCatagenesisgeology–Thecrackingprocessinwhichorganickerogensarebrokendownintohydrocarbons;Catagenesisbiology–Retrogressiveevolution,ascontrastedwithanagenesis.,22,,Metamorphismcanbedefinedasthesolidstaterecrystallisationofpre-existingrocksduetochangesinheatand/orpressureand/orintroductionoffluidsi.ewithoutmelting.Therewillbemineralogical,chemicalandcrystallographicchanges,23,,Prolongedexposuretohightemperatures,orshorterexposuretoveryhightemperatures,mayleadprogressivelytothegenerationofhydrocarbonmixturescharacterizedascondensates,wetgasesandgas.Theaverageorganiccontentofpotentialsourcerocksisabout1byweight.TheKimmeridgeclay,theprincipalsourcerockforNorthSeaoilaverageabout5carbon7organicmatterwithlocalrichstreaksgreaterthan40.Thehydrogencontentoftheorganicmattershouldbegreaterthan7byweightforpotentialasanoilsource.,24,,Itisaruleofthumbthatforeachpercentagepointoforganiccarboninmaturesourcerocks,some13001500cubicmetersofoilperkm2-mor1040barrelsofoilperacre-ft;or56-225ft3/43560ft3ofsedimentcouldbegenerated.125210,00018331200Itisnot,however,necessarilytruethatalltheoilgeneratedwillbeexpelledortrappedinporousrock.,25,石油移棲,,Themigrationprocessinvolvestwomainstages,namelyfromthesourcerockandthenthroughapermeablesystem.,26,Migrationofpetroleum--fromthesourcerock,27,Migrationofpetroleum--fromthesourcerock,**Capillaryeffect**MicrofracturesSincethegenerationofpetroleumisaccompaniedbyvolumechangeswhichcanleadtohighlocalpressures,theremaywellbeaninitiationofmicrofractureswhichprovideanescaperouteintopermeablesystemssuchassedimentaryrocksorfaultplanes.Thesourcerockmicrofracturesarebelievedtohealaspressuresaredissipated.,28,Migrationofpetroleum--throughapermeablesystem,**FluidpotentialgradientorgravityeffectInthepermeablesystemthetransportoccursunderconditionsofafluidpotentialgradientwhichmaytakethehydrocarbontosurfaceortosomeplacewhereitbecomestrapped.Itmightbeassumedthatlessthan10ofpetroleumgeneratedinsourcerocksisbothexpelledandtrapped,asshownintheexampleofFig.2.5.,29,30,Petroleumtraps石油封閉,Thecharacteristicsofpetroleumtrapareknownasstructuraltraps構造封閉andstratigraphictraps地層封閉,withthegreatmajorityofknownaccumulationbeingintheerstyle.,31,地質構造（GeologicalStructures）,,32,,Figure1.12.TwogeneralkindsofunconitiesaredisconityAandangularunconitiesBandC.,Figure1.13.Basichydrocarbonreservoirsarestructuraland/orstratigraphictraps.,33,封閉traps,,Combinationtraps,34,Caprockandfluiddistribution,Impermeablerocksprovidesealaboveandbelowthepermeablereservoirrocks.Atequilibriumconditions,thedensitydifferencesbetweentheoil,gasandwaterphasescanresultinboundaryregionsbetweenthemknownasfluidcontacts,i.e.gas-oilandoil-watercontacts.,35,Structuraltrap構造封閉--Anticline,,Longitudinalviewofatypicalanticline.Theoilcannotescapeupwardbecauseoftheimperviousshalebedabovetheoilsand;neithercanittraveldownwardbecauseofthewaterthatisassociatedwithanaccumulationofthistype.,Anticlines－Ofthemanytypesofstructuralfeaturespresentintheupperlayersoftheearthscrustthatcantrapoil,themostimportantistheanticlines－thetypeofstructurefromwhichthegreaterpartoftheword’soilhasbeenproduced.Anticlinesareupfoldsofbedsintheearth’scrust,and,whentheproperconditionsarepresent,oilaccumulateswithintheclosureoftherefolds.,36,Structuraltrap--Anticline,,Lateral,orendview,ofatypicalanticline.,Planviewofatypicalanticline,showinglocationsoflongitudinalviewA-BandlateralviewC-D.,37,Structuraltraps,Figure1.7.Schematiccrosssectionshowsdeationofearth’scrustbybuckingoflayersintofolds,Figure1.8.SimplekindsoffoldsaresymmetricalanticlineA,plungingasymmetricalanticlineB,plungingsynclineC,anddomewithdeepsaltcoreD.,Figure1.9.SimplifieddiagramoftheMilano,Texas,fault.,38,Structuraltraps–domesurfaceerosionOsmosisbetweenwatershavingdifferentsalinity,thesealingshaleactingasthesemipermeablemembraneinthisionicexchange;ifthewaterwithinthesealismoresalinethanthesurroundingwatertheosmosiswillcausetheabnormalhighpressureandviceversa.,89,,,90,,,91,,,92,,,