Study Of Well Test Interpretation Model In Stress-sensitive Reservoir

The methods commonly used to describe the transient flow behavior in porous media have been based on the assumption of constant rock properties,However,these methods are not strictly applied to reservoirs that experience changes in permeability with pore pressure.On one hand,inclusion of pressure-dependent permeability makes the governing equation for the pressure in the reservoir nonlinear,and a perturbation technique is widely applied to determine approximate analytical solutions.Many scholars solve the nonlinear equation to the zero order of accuracy for convenience,but the question whether the zero order perturbation solution can satisfy the accuracy of the solution is scant.Besides,there is few research touching upon pressure buildup analysis.From what I have mentioned above,the main research content includes:(1)A homogeneous oil reservoir model considering well-bore storage and skin effect and stess-sensitive has been built.By using the MATLAB programming,the dimensionless bottom-hole pressure and its derivative of a vertical well with three boundaries including infinite boundary and closed boundary and constant pressure boundary have been obtained.Moreover,the characteristics of the dual-logarithm curves and its influential factors such as well-bore storage have been analyzed considerably.Finally,the numerical solution obtained by Saphir simulation was compared with the zero order perturbation solution in order to verify the reliability of the zero order solution.(2)A dual-porosity oil reservoir model with consideration of well-bore storage and skin effect and stress-sensitive has been built.By using the MATLAB programming,the dimensionless bottom-hole pressure and its derivative of a vertical well with three boundaries have been draw.Moreover,the characteristics of well test curves and its influential factors such as storage ratio and inter-porosity flow coefficient have been discussed.Finally,the numerical solution obtained by Saphir simulation was compared with the zero order perturbation solution in order to verify the reliability of the zero order solution.(3)Taking well-bore storage and skin effect and pressure-dependent permeability into consideration,a nonlinear composite oil reservoir model has been built.By using the MATLAB programming,the dimensionless bottom-hole pressure and its derivative of a vertical well with three boundaries have been obtained.Moreover,the characteristics of well test curves and its influential factors such as mobility ratio have been discussed.Finally,the numerical solution obtained by Saphir simulation was compared with the zero order perturbation solution in order to verify the reliability of the zero order solution.(4)The pressure buildup analysis of the three models is carried out,and t the pressure test well are compared and analyzed.Through the study of well test analysis theory in above different models,we can know characteristics of bottom-hole pressure dynamic response better,which can provide theoretical guidance for well test interpretation in practical work.