Study On Sedimentary Microfacies And Remaining Oil Distribution Of P?3-P?2 In The Beiyi District Of Daqing Oilfield

The development degree of the east of the fault block in Beiyi district of Daqing oilfield has come to high water-cut stage of development.In this stage,grasp underground geological conditions of reservoir is important to tap the remaining oil.So it is important to study the sedimentary microfacies and the internal architecture of single sand body detailedly,in order to understand the seepage characteristics.Only in this way,we can study the distribution rules of the remaining oil better.The deposition units of P?3-P?2 in the study area controlled by different river systems.The depositional systems are divided into subfacies and microfacies.Through the study we found that the P?2 is delta plain reservoir and can be subdivided into three sedimentary units(P?21,P?22a and P?22b).The P?3 has developed the distributary channel sand and sheet sand of delta-front facies.In order to understand the internal structure of the reservoir better,we should further study on the structure of single channel sand body.Firstly,the single channel and single point bar are identified through abandoned channel and the difference of sand layer position.Secondly,the interbeds that are formed through the rivers' lateral accretion process can influence the distribution of the remaining oil.So through extracting the parameters of architecture anatomy including the tendeney,dip and the space distributions,and using the channel sand body architecture model,we fonns internal structure model of the typical single sand body.It further researches the seepage characteristics of internal single sand and control of interlayers for oil and gas to provide a basis for finding the remaining oil.