惠州凹陷惠州26洼古近系油气相态特征与成因机制

打开文本图片集

中图分类号：TE122.3 文献标志码：A

Abstract：The Huizhou26sub-sag isrichinoilandgasresources，butitsfluid phasesarecomplexandvariable，with unknownorigins.Basedoncrudeoil properties，wellfluidcompositions，ndorganicgeochemicaldata，this studyappliesempirical statisticalmethodsandPVTphasediagrams toidentifythehydrocarbonphase types inthearea.Thespatial distributioncharacteristicsand genetic mechanismsofthese phases areanalyzed.Throughacomprehensiveexaminationofthe formationstagesand processesof diferentreservoirtypes，threephaseevolutionmodelsare proposed：initialoil-phasefiling， two-stageoil-phasesuperposition，andearlyoil-phasefollowedbylategas-phasecharging.Theresultsprovidetheoretical guidancefortheeficientexplorationofdeephydrocarbons．ThecrudeoilfromHuizhou26sub-sagischaracterizedbylow density，lowviscosity，lowsulfurcontent，ndhighwaxcontent.Threehydrocarbonphasetypesareidentified：blackoil， volatileoil，andcondensategas.Amongthese，blackoilisthemostwidelydistributed，whilevolatileoilandcondensategas occur mainlyintheHuizhou26-6and21-8structuralzones.Verticaly，theEnpingFormationisdominatedbyvolatileoil andcondensategas，whereas blackoil，volatileoil，andcondensategascoexistintheWenchangFormation.Somewelsdisplayverticalalternationofoilandgasphases.Thespatialvariabilityofoilandgasphasesisprimarilycontrolledbythethermal maturityof sourcerocksand the hydrocarbon charging process.Specifically，the maturitylevel of hydrocarbons during themain filing stageandtheextentof latemixingwith high-maturityhydrocarbonsarethekeycontrollingfactors.

Keywords：Huizhou Depression；oil and gas phases；condensate gas；differential filling of oil and gas

近年来油气勘探层系逐渐向深层拓展，复杂油气相态是深层油气勘探面临的一大难题，也是揭示油气成藏过程的一个重要抓手[1-4]。（剩余14974字）