Quality Shale Reservoir Evaluation And Geological Modeling Of Longmaxi Formation In Changning Area,Sichuan Basin

Shale gas resources are abundant in China,and the productivity construction of some production areas in Sichuan Basin has begun to take shape.However,the exploration and development of shale gas in China started relatively late,and there are few practical schemes for shale reservoir classification at the development level.At present,there are few vertical wells in Changning area of Sichuan Basin.Shale gas is usually developed by horizontal wells.There are few studies on three-dimensional geological modeling of shale reservoirs.The factors affecting productivity of horizontal wells are unknown.The optimization design of horizontal wells is a major difficulty in the process of gas field development.This study takes the high-quality shale reservoir at the bottom of Longmaxi Formation in N201 block of Changning,Sichuan Basin as the research object,and comprehensively utilizes the data of core,well logging,test and analysis of key wells to clarify the heterogeneity characteristics of shale reservoirs among small layers.Slecting the key parameters of reservoir characterization.The "binary index",representing the material basis and engineering parameters of the reservoir,is used to classify and evaluate the shale reservoir.To fully excavate the data of horizontal wells in the study area,establishing a quantitative identification standard for lithology,physical properties and electrical characteristics of reservoirs,and using this standard to delineate the horizontal section.The corrected horizontal reservoir is equivalent to several vertical wells with planar distribution.On this basis,the three-dimensional geological model of reservoir in the study area is established by taking the analytic data of each layer in the horizontal section as the control point and combining with seismic data.The lithofacies are divided by "three-terminal element method of mineral composition",The lithofacies model,key geological parameter model and engineering attribute parameter model are established by multi-point geostatistics modeling method.On this basis,the factors affecting the productivity of horizontal wells are analyzed,and the horizontal well optimization design is carried out.