Design And Application Of Well Pattern With Different Fracture Modes In Fractured Reservoir

The existence of fractures in fractured reservoir aggravates the heterogeneity of reservoir,but limited by the current reservoir fracture identification technology,it is unable to accurately describe the detailed characteristics of fractures in the reservoir,so it is a challenge to establish fracture model.In this paper,through the comparative analysis of the difference between the traditional dual medium model and the discrete fracture network model(DFN model),the best model is selected as the basis of the follow-up study.In this paper,by analyzing the causes of the heterogeneity and anisotropy of fractured reservoirs,and through the theoretical formula derived from the percolation model of fractured heterogeneous composite reservoirs,combined with the two,we can get the key indicators of fracture reservoir:the ratio of fracture permeability K_fto matrix permeability K_f/K_m and fracture linear density D_f.Based on a large number of fracture reservoir data as classification samples,using cluster analysis tool SPSS to classify the sample data can to some extent avoid the blindness of data classification relying on experience,and pave the way for the follow-up research work.Through cluster analysis,the sample data is divided into four patterns,and the critical value of classification index is determined.Based on the above four fracture modes,the DFN model is established by extracting basic geological and reservoir parameters from a fractured reservoir in China,and the optimal well pattern form,well spacing and water injection timing under the four modes are studied respectively.The research results have important practical significance for guiding the development of fractured low-permeability reservoir.