Reservoir Characteristics And The Residual Oil Distribution Of The 2nd Member Of Shuangyang Formation In Chang10 Block Of Changchun Oil Field

Changchun Oil field Chang 10 block is located in the northeast of five-star structural belt of Luxiang faulted depression,and the study area is only 0.5km2.2nd member of Shuangyang Formation is the main oil producing reservoir of this block.In this paper,the three-dimensional seismic data body,secondary interpretation and physical property parameter data of the working area are combined with exploration geophysics,sedimentology and petroleum geology as the theoretical support.The landmark and double fox software are used to carry out the microstructure study and analyze the reservoir characteristics,the relationship between reservoir formation conditions and residual oil,and then combined with the physical property parameters to divide the flow unit.Finally,considering the sedimentary microfacies,the microstructure types and the flow unit division result,we use the method of superposition analysis to predict the main residual oil distributions of the 2nd member of Shuangyang Formation.Specific contents are as follows:1)The types and distributions of microstructureBy using landmark,we get seismic synthetic record of 33 wells in the working area,and on this basis,we identify seismic reflection layer and fracture location,then we make the structural contour maps of sand group interface.Finally,56 positive microstructure distributions are identified.The positive microstructure includes 3 kinds:micro-anticline,micro-nose and micro-cut-off.2)The petroleum system and reservoir typesThe reservoir is lower generation and upper storage pattern oil-gas accumulation whose main source of oil is from the 1st member of Shuangyang Formation.A large number of source rocks provide the basis for the formation of reservoir,meanwhile,the 2nd member of Shuangyang Formation also developes a large number of river sand bodies.The reservoir properties of sand bodies are well,so the sand bodies can be used as a favorable reservoir.Mudstones of the3 rd member of Shuangyang Formation are thick and distributed in this region,so it can form a stable area cap layer.There are many types of reservoir in the area,which can be divided into three major categories:structural reservoir,lithologic-structural reservoir and lithologic reservoir.The structural reservoir can be divided into anticline reservoir,cut-off reservoir and nasal reservoir.Lithologic-structural reservoir is mainly sandstone lenticular-structural reservoir.The lithologic reservoir can be divided into sandstone lenticular reservoir and sandy updip pinchout reservoir.3)Flow unit division and the residual oil distribution area preferredBased on the former comparison of the small layer and the analysis of the physical properties,the physical parameters of the sand bodies in the 36 wells of working area are calculated and the frequency-probability cumulative curve of the seepage parameter J is established.According to the different slopes of the frequency-probability curve,flow units are divided into four categories: J≤500,500 <J≤1500,1500 <J≤4000 and J> 4000.The flow unit plane figures are made by the boundary of sedimentary facies and the breakpoints of fault.The flow unit plane figure is stacked with the microstructure,and residual oil distribution areas are finally optimized.This study provides the goal for formulating the measures of tapping the potential areas.