裂缝性低渗油藏注气提高采收率实验研究

HH油田为典型的低孔特低渗油藏,部分地层伴有裂缝发育,现面临衰竭式开采后注水开采压力高的难题.通过基质单管岩心驱替实验,探究目标地层进行注气开发的可能性,明确何种注入气体及驱替方式具有较好提高采收率效果.通过基质+裂缝双管并联岩心驱替实验,确定目标地层中微裂缝对提高采收率效果影响.结果表明,CO2较减氧空气是更好的注入...

Experimental study on gas injection enhanced oil recovery of fractured low permeability reservoir

HH oilfield is a typical low porosity and ultra-low permeability reservoir with fracture development in some strata.Now it is facing the problem of high water injection production pressure after depletion production.Through the matrix single tube core displacement experiment,explore the possibility of gas injection development in the target formation,and clarify what kind of injected gas and displacement method have better EOR effect.Through the matrix-fracture double tube parallel core displacement experiment,the influence of micro fractures in the target formation on EOR is determined.The results show that CO₂ is a better injection gas than oxygen reducing air,and CO₂/water alternative displacement is an excellent displacement method to enhance oil recovery;The existence of fractures will seriously affect the recovery.Compared with single tube matrix core,the recovery of CO₂/water alternative drive in fracture+matrix double tube parallel core is reduced by 27.09%.It is suggested that CO₂ should be selected as the injection gas and CO₂/water alternate development should be adopted for the matrix reservoir or the fractured area with measures to improve heterogeneity,which has a certain reference significance for the gas injection production of fractured low permeability reservoir.