Study On Numerical Simulation Method Of Low-Permeability Reservoir Flow

In recent years,the development of low-permeability reservoirs is increasingly important for the oil industry in China.However,compared with high-pernneability reservoir,fluid flow of low-permeability reservoir shows obvious non-linear characteristics.Besides,the impacts of starting pressure gradient and stress sensitivity on low-permeability reservoir can not be ignored,which makes low-permeability reservoir development more difficult.Basing on the previous studies of low-permeability reservoir.researches of flow mechanism and numerical simulation method are deeply studied,and the conclusions and understanding can be specifically expressed as follows:1.Considering the analysis of oil boundary layer fonnation mechanism and influencing factors,the study of the nonlinear characteristics flow of reservoir fluid is finished;through the analysis of the flow characteristics curve and rock deformation mechanism.,this thesis finished the research of starting pressure gradient and stress sensitivity mechanism.2.Considering average starting pressure gradient and stress sensitivity,a new three-dimensional oil-water mathematical model is set up,through the change of mathematical model,the role of the average starting pressure gradient in the mathematical model can be more reflected.3.IMPES and fully implicit method are applied for the solution of the numerical model.4.Numerical reservoir simulator of low-permeability reservoir is developed,which is verified by compared with ECLIPSE.The research of fluid flow and productivity with different characteristic factors and injection-production patterns has been done by this simulator.The results show that with the increasing of starting pressure gradient and stress sensitivity,the influence on fluid flow and productivity is relatively increasing,and by the comparison of different injection production well pattern,the stable time of linear and inverted seven-point well pattern is longer,and inverted nine and linear well pattern are superior to other well patterns on the degree of reservoir recovery after 10-year development.