夹层型页岩油注CO₂吞吐提高采收率动用机理及埋存前景

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关键词：鄂尔多斯盆地；页岩油；提高采收率； CO2 吞吐；核磁共振；物理模拟；数值模拟；产油及埋存中图分类号：TE927 文献标志码：A 文章编号：1000-7393（2025）-02-0245-10

Abstract：Toadressthcallengsofowfomationpressureapddlieinoztalwels，ndieftivewaterectiote Triassic Chang7shaleoilreservoirofOrdos Basin，thisstudyinvestigates the microscopic mechanismsofgasinjectionforhanced oil recovery （EOR） and develops eficient development methods for continental shale oil. The study integrates CO2 huff and puff experiments withnuclear magneticresonance （NMR）technologytoquantitativelycharacterizeoilrecoveryeficiencyandresidualoil  distribution under varying injection durations.Physical simulation experiments replicate in-situ CO2 injection processes to analyze hydrocarbon fractionatioandtheimpactofpriorwaterinjectionongas injectioneficacy.Fieldtrialsareconductedinhorizontal welswithin theX233wellblockofLongdongarea，supportedbynumercalsimulations tooptimize gasinjectionparameters.NMR results indicate that CO2 initially mobilizes oil from large pores， with small-pore oil gradually activated over time， showing weak corelatin withporosityandpermeability.Physicalsimulationdemonstratesthatwithincreasinghuffandpuffcycles，cudeoil componentsexhibitdistinctfractionationcharacteristics，where lighthydrocarbonsarepreferentiallyextractedandheavy hydrocarbons gaduallacumulate.Fieldapplications demonstrate thatoptimizedsynchronoushuffandpufenhances single-wel estimated ultimate recovery（EUR） by 50.4% ，elevates formation pressure by 25%-29% ，confirming the effectiveness of gas injection in low-pressure shale oil reservoirs. CO2 huff and puff enhances shale oil recovery through selective extraction of light hydrocarbons and pore-pressresynergy.The synchronous injectionmodeis economicallyviable but requiresavoidingpre-water injection interferene.Tisstudyprovides teoreticalandtecnicalfoundationsforteefcietdevelopmentofontinentallow-prsreshale oil reservoirs.

Keywords：Ordosbasin;shaleOil;EOR;carbondioxidehuffandpuf;uclearmagneticresonance;physicalsimulation;umerica simulation; oil production and storage

0 引言

中国页岩油资源丰富，已探明资源储量达到283亿 ，其中鄂尔多斯盆地三叠系延长组长7段页岩油资源量达到42.3亿t[2]。（剩余18358字）