Remaining Oil Distribution And Tapping Potential Of Putaohua Oil Layer Of Wei 25-W251 Well Area In Weixing Oilfield Of Daqing Area

Wei 21-Wei 251 block is the main oil bearing block of the Weixing Oilfield.After more than 10 years of development,it has entered the stage of high water cut.There are many problems of low yield and low efficiency well ratio,low formation pressure keeping level and low density edge well network density,which restrict the efficient development of the next step of the grapevine oil layer.Therefore,it is necessary to carry out the study on the remaining oil distribution of Putaohua oil layer of Wei 21-Wei 251 well area.In this paper,guided by sedimentary petrology,reservoir geology and geostatistics,comprehensively applies the predecessors’ research results,regional background,dynamic production and analysis and testing,etc,and uses the method of reservoir 3D geological modeling and numerical simulation,the remaining oil distribution of Putaohua oil layer of Wei 25-W251 well area is analyzed.On the basis of previous research results,the sedimentary background,sedimentary microfacies and sand body distribution of the Putaohua oil layer in the study area are determined,and the characteristics of reservoir lithology,physical property and heterogeneity are analyzed,and the characteristics of reservoir temperature pressure,fluid and oil and water distribution are also analyzed.Based on the above features,the grid precision of reservoir 3D geological modeling is determined.The structure model,sedimentary microfacies model,fluid distribution model and reservoir property model are established,and the model is coarsened on the basis of the 3D geological model,and the numerical simulation analysis is carried out on the study area,and the fitting of geological reserves,the fitting of dynamic parameters of the whole area and the dynamic parameter fitting of the single well are completed.Numerical simulation results based on the above reservoi,combined with the geological characteristics of sedimentary microfacies and reservoir heterogeneity,the type of residual oil is determined,and the distribution of remaining oil is analyzed from two aspects of plane and vertical.The study shows that there are four main types of remaining oil in the study area: fault occlusion residual oil,plane interference residual oil,interlayer interference residual oil and imperfect injection and production residual oil.In the plane,the remaining oil is mainly concentrated in the west of the west fault in Wei 21 well area and the midwest of Wei 102-Wei 251 well area.Vertically,the small layer of the PI2 in Wei 21 well area and the PI3,PI4 and PI5 layers of Wei 102-Wei 251 well are the main enrichment areas of the remaining oil.On the basis of the study of the distribution law of remaining oil,the design of the remaining oil digging scheme is carried out.According to the principle of the scheme design of the remaining oil,3 ports and 13 straight wells are determined,and the development indexes are predicted.This provides a reliable geological basis for the development of the next oil field,and also a high water cut oilfield.The sustainable development provides an important guarantee.