Research And Application Of Nonlinear Flow Numerical Simulation In Ultra-Low Permeability Reservoir

In this dissertation, the laboratory physical simulation, seepage flow mechanics and numerical computation were used to systematically study the method and application of the nonlinear flow numerical simulation on the basis of the flow mechanism of ultra-low permeability reservoir and the previous research. The main research results are as follows:(1) The nonlinear flow characteristic of ultra-low permeability reservoir was verified. The nonlinear flow mathematical model of ultra-low permeability reservoir which includes the basic assumptions, mathematical equations, boundary conditions and the initial conditions was established based on the nonlinear flow model.(2) Block-centered seven-point finite difference was used to process the nonlinear flow mathematical model of ultra-low permeability reservoir, and the dimensionless permeability coefficient was introduced to modify absolute permeability. The well-grid equations were deduced. The alternate iteration method was selected to solve the corresponding numerical model.(3) The nonlinear flow numerical simulator was developed, and the simulator includes four modules:Geological Map Numeralization Module, Reservoir Numerical Simulation Parameters Collection Module, Three-Dimensional Dynamic Visualization Analysis Module, and Plan Comparison Module.(4) The zero-balance validation, symmetry validation, sensitivity analysis of the nonlinear flow parameters, the simulation results comparison between the nonlinear flow numerical simulator and general commercial reservoir simulator were provided to verify the stability of nonlinear flow numerical simulator.(5) The plane heterogeneity, vertical heterogeneity and typical well pattern geological models were established based on actual field data. The nonlinear flow numerical simulator was used to simulate these ideal models and study the effect of nonlinear flow characteristics on the development of ultra-low permeability reservoir.(6) The nonlinear flow numerical simulator was used to perform an integrated numerical study on the typical blocks of Jilin and Changqing Oilfield. The primary goal is to put the nonlinear flow numerical simulator into field application. The well adaptability and effective drive pressure system were studied and the optimum well plans and well adjustment opportunity were determined by the designed well plans.