The Research On The Relationship Between Single Well Controlled Recoverable Reserves And Reservoir Parameters In Beach-bar Sand Reservoirs

Beach-bar sand reservoirs,as an important low-grade and difficult-to-produce reservoir type in my country,have great development potential.Single well control of recoverable reserves is the basis and important indicator for determining whether new wells and stimulation measures are economically feasible.In the development of ultra-low permeability beach-bar sand reservoirs,it determines the importance of quantitative study of single well control of recoverable reserves.However,there are many reservoir parameters and development parameters that affect the recoverable reserves of a single well in ultra-low permeability beachbar sand reservoirs.Therefore,studying the relationship between single well controlled recoverable reserves and reservoir parameters of ultra-low permeability beach-bar sand reservoirs under different development methods and fracturing methods can provide a basis for evaluating the production potential of beach-bar sand reservoirs.This research mainly adopts semi-analytical solution and reservoir numerical simulation analysis method.In the study of semi-analytical solution method,the productivity equation of single well fracturing was established according to the seepage characteristics of the elastic development of ultra-low permeability beach-bar sand reservoirs.According to the law of production decline in ultra-low permeability reservoirs,a full-cycle production decline model is constructed.The productivity equation and the full-cycle production decline model are combined to obtain a semi-analytical solution model for single well controlled recoverable reserves in beach-bar sand reservoirs.In the research using reservoir numerical simulation technology,based on static data and dynamic data of typical wells in typical blocks,reservoir numerical simulation technology is used to establish a single well model that is consistent with actual reservoir characteristics.With the aid of numerical simulation technology,the influence degree of each reservoir parameter value in a certain range on the single well controlled recoverable reserves of vertical well stratified fracturing elastic development is calculated and analyzed,and the main controlling factors are established in combination with orthogonal design.Based on the data samples generated by factor analysis,a calculation formula for single well controlled recoverable reserves was established through multiple regression methods.The calculation formulas for single control recoverable reserves of beach-bar sand reservoirs with different well types and different fracturing scales under two different development methods,elastic development and water injection development,have been further established and the relationship chart of reservoir parameters.The research results show that,after comparing with the actual developed single well controlled recoverable reserves,the semi-analytical solution for beach bar sand single well controlled recoverable reserves established by the semi-analytical solution mathematical model predicts an error rate of less than 20%.Through numerical simulation analysis,the main controlling factors of permeability,effective thickness,oil saturation,pressure coefficient,viscosity,concentration and half fracture length are established.The established multiple regression models of single well controlled recoverable reserves with different development methods and fracturing methods have a prediction accuracy of more than 90%.Based on the multiple regression model,the single well controlled recoverable reserves of beach-bar sand reservoirs can be obtained under different development conditions.The relationship chart with influencing factors is used for the prediction of recoverable reserves in engineering.