Study On Reservoir Heterogeneity Of The 4th Member Of Quantou Formation In Liangjing Oilfields In Jilin Province

Fuyu oil layer of Liangjing oilfields has realized the benefit production of local high-quality reserves,although the degree of reservoir heterogeneity becomes much worse than ever,the prediction of distribution of remaining oil becomes much more difficult neither.Based on the research achievements of sedimentary system of the south of Songliao Basin,combined with the collection and analysis of logging data,core data,test data and oilfield production data of the 4th Member of Quantou Formation in the study area,and applying the principles of sedimentary petrology,high-resolution sequence stratigraphy,reservoir geology and oil and gas field development.Relying on the studies of reservoir distribution and reservoir physical property,the characteristics of the reservoir heterogeneity of the study area are systematically analyzed.On this basis,the role of reservoir heterogeneity controlling the distribution of remaining oil was discussed in detail.Finally,the remaining oil distribution areas were predicted.The research shows that the 4th member of Quantou Formation in the study area is mainly shallow water delta deposit,with delta plain and front subfacies developed.The distributary channel and underwater distributary channel are the dominant facies belt,and the channel migrates and overlaps to form composite sand bodies.According to the core physical property analysis data,the logging interpretation model of reservoir physical properties of non coring wells in the study area is established,which shows that the reservoir in the study area belongs to low porosity and low permeability reservoir,and the areas with good physical properties are mostly the middle of the river channel and the interconnected distribution area of the river channel.Furthermore,the paper studies the reservoir heterogeneity from the aspects of intralayer,interlayer and plane,and analyzes the difference of reservoir quality.The comprehensive study of heterogeneity shows that the reservoir of the 4th member of Quantou Formation in the study area presents medium strong heterogeneity.The comprehensive analysis shows that the main controlling factors of the remaining oil distribution in the study area are reservoir heterogeneity,sedimentary microfacies and sand body characteristics.Combined with the characteristics of reservoir distribution and development,reservoir physical properties and reservoir heterogeneity,a set of standards for predicting the favorable areas of remaining oil distribution are put forward,and the favorable areas are predicted.