The Influence Of Reservoir Heterogeneity On Remaining Oil Distribution Of Putaohua Reservoir In Fang33 Block Of Daqing Oilfield

The Putaohua reservoir in Fang33 block of Daqing Oilfield is a typical "thin reservoir",with the development of sand bodies inside the reservoir,uneven development of sand bodies of different thickness levels,a large number of interlayers inside the sand body,and large permeability difference,which makes the heterogeneity of the reservoir more serious.At the same time,under the influence of heterogeneity,intra-layer,inter-layer and planar contradictions are prominent,such as intra-layer heterogeneity leading to intra-layer "pointing" and inter-layer heterogeneity leading to "single-layer outburst".In addition,as the oil field enters the late development stage of high water cut,the distribution of remaining oil in the reservoir is very complex and scattered,so it is urgent to carry out reservoir heterogeneity research,analyze how the reservoir heterogeneity affects the distribution of remaining oil,and find out the enrichment location of remaining oil,which has important guiding significance for improving oil recovery.In this thesis,the sedimentary characteristics were analyzed by using the data of the closed coring well,the provenance direction and the sedimentary environment of the study area were defined,and the sedimentary characteristics of each depositional time unit of the target layer were analyzed.Secondly,on the basis of the study of sedimentary characteristics,combined with core data,logging data,tracer data,production dynamic data and numerical simulation data in the target area,using geological genetic analysis,traditional mathematical statistics,mathematical function method and geological modeling method to carry out qualitative and quantitative description of intralayer,interlayer and plane heterogeneity.The heterogeneity of Fuhua reservoir in Fang33 block of Daqing oilfield is characterized.Finally,based on the results of heterogeneity characterization in various aspects,the influence of intra-layer,inter-layer and planar heterogeneity on the distribution of remaining oil was analyzed by means of development geology method,waterlogging interpretation method and reservoir numerical simulation method,and the enrichment location of remaining oil was found out.The study says:1.The macro heterogeneity of the study area is strong,the intra-layer heterogeneity is moderate to strong,the interlayer heterogeneity is strong,and the plane heterogeneity is moderate.2.Reservoir heterogeneity has a great influence on the distribution of remaining oil.The stronger the heterogeneity is,the higher the enrichment degree of remaining oil is.The remaining oil in the reservoir is more likely to be enriched in the middle and upper low permeability section of positive rhythm,the lower part of negative rhythm,the upper part of negative composite rhythm,the middle and upper low permeability section of positive and negative composite rhythm,and the bottom of the top of the interlayer.3.There is a great difference in the oil production status among different reservoirs,and the degree of remaining oil enrichment is different.Under the influence of sandstone thickness,sand bodies of different genetic types and permeability value,the low permeability layer has high oil saturation and high possibility of remaining oil enrichment.The distribution of the remaining oil on the plane is mainly controlled by sedimentation,and the remaining oil is more likely to be enriched in sheet sand,overflow bank sand,narrow and small channel,and the channel sand body physical property variation zone.4.The original geological reserve base of the underwater distributary channel and the distributary channel is large and the channel sand body still has the most potential for remaining oil exploitation.In the case of reservoir heterogeneity,the remaining oil can be divided into three types: intra-layer interference remaining oil,interlayer interference remaining oil and plane interference remaining oil.Among them,the remaining oil of intra-layer interference type and interlayer interference type have large geological reserves and are the main potential targets in the future.