塔里木盆地轮南地区奥陶系原油性质差异及其控制因素

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中图分类号：TE122.3 文献标志码：A

Abstract：ToinvestigatethecontrolfactorsndregionaldiferencsinthepropertiesofOrdoviciancrudeoilintheLunaarea of TarimBasin，asystematiccomparativeanalysis was conducted usingoildensity，waxcontent，gas-oilratio，andthecontents of saturated hdrocarbonsandaromatics.These parameters were examined inconjuntion withthe timing ofoilandgascharging andtheefectsofsecondaryalterations，inordertoclarifythespatialvariationsandcontrllingmechanismsofcudeoilproper tiesbetween theeasternand westernregions.Theresults indicate that crudeoil densityintheLunnanarea folowsapattemof being heavier intheeast and westandlighterin the midle.Incontrast，waxcontent，gas-oilratio，saturated hydrocarbon content，andoilmaturityparametersexhibita"lowerinhewest，higherintheast"distribution.Variationsinfaultactivityduringdierenttectonicperiodshaveresultedinspatialheterogeneityinmulti-phasehydrocarbonchargingandsecondarymodification，whichultimatelycontrolcrudeoilcharacteristics.HydrocarbonchargingintheLunnanareaoccurredduringfourmajororogenic events：thelate Caledoniantoearly Hercynian，late Hercynian，Yanshan，andlate Himalayanorogenies.Inthe Lunguxiarea，primaryoil chargingoccurrd mainlyduring thefirsttwoorogenies，with limitedevidenceof charging during the third.Tisareaischaracterizedbyheavyoilreservoirsduetosignificantbiodegradation.Onthecentral platform，oilcharging during thefirst twoorogenieswas dominant，with some welsalsoindicating high-maturityoil and gasinput during laterorogenies.Lower degreesofbiodegradationand evaporativefractionationinthisregion have esultedinpredominantlynormaloiland condensategasreservoirs.IntheLungudong area，oilandgascharging occurred duringallfour orogenies，accompaniedbyevaporative fractionation，leading to the predominance of medium-heavy oil and dry gas reservoirs.

Keywords：Tarim basin;Lunnan area； oil properties； secondary alteration

塔里木盆地深层油气资源丰富，海相油气储量达 50×108t 油当量[1-3]，是中国重要的海相含油气盆地，目前已经在塔北、塔中、富满、库车等地区发现了多个大型油气田[49]。（剩余18549字）