Numerical Simulation On Factors Affecting The Productivity Of Fractured Horizontal Wells In Shale Gas Reservoir

In order to realize the dynamic characteristics of shale gas production,and improve the shale gas well ultimate recovery,the study of shale gas reservoir flow mechanism and factors affecting productivity have important theoretical and practical significance.The main difference between shale gas reservoir and conventional gas reservoir is the adsorption desorption characteristics.The study of shale gas occurrence,migration mechanism and dynamic numerical simulation of shale gas reservoir,with the purpose of exploring the inherent law of fluid flow in shale gas reservoir,and create the conditions for improving the gas production rate and ultimate recovery,which has great significance to shale gas efficient development.In view of the adsorption,desorption,diffusion,slip and seepage characteristics in the process of occurrence,migration and output,the dual medium shale gas reservoir percolation mathematical model of unsteady is established which considering Langmuir desorption effect,Fick diffusion and Klinken-berg effect.In order to solve the shale gas seepage mathematical model,IMPES method is used to derived and establish shale gas reservoir seepage numerical model which can be iterative solution.With the application of numerical simulation software to study the production dynamic characteristics of shale gas horizontal wells,simulation well production performance curve under different ways of drilling based on ideal geological model.By contrast,it is concluded that for shale gas exploration,with the method of horizontal drilling method and reservoir reconstruction,shale gas reservoir recovery could be effectively improved.Analysis the effects of gas reservoir parameters and horizontal well fracturing parameters on gas production respectively,the results show,that under the condition of fracture parameters in certain,natural fracture and reservoir thickness have bigger influence on gas production.For a given shale gas reservoir,under the condition of geological conditions being equal,fracture number,fracture half-length,fracture width and fracture conductivity are not the bigger the better,there should be an optimal value,which could maximize economic benefits.And through the orthogonal experiment got the importance ranking of fracture parameters effecting fracturing well productivity,that is fracture half-length,fracture number,fracture conductivity and fracture width.