In the process of shale gas recovery,hydraulic fracturing technology is needed to form fracture net-work system.In order to study the influence of natural fracture characteristics on the seepage in shale reservoirs,this paper derives a mathematical model for describing the gas seepage behavior in the fractured area of the reservoir based on the law of mass conservation in shale reservoirs,the Langemuir adsorption equation and Darcy's law,etc.The mathematical model is used to describe the gas seepage behavior in the fractured area of reservoir;Numerical simulation with the introduced embedded discrete fracture model is performed based on this mathematical model,and the model is verified by comparing the simulation results with the existing litera-ture data,as well as the actual production data on site;The verified model is used to investigate gas flow behav-ior influenced by natural fractures,where the permeability,densities and orientation are proved to have an ob-vious effect on seepage behavior.Increasing the natural fracture permeability amplifies the effects of inclina-tion angle and fracture density on reservoir flow,and the maximum of influence reaches about 10％.The higher fracture density enhances the impact of permeability while weakening the influence of inclination angle on res-ervoir flow,and the maximum of influence reaches about 6.3％.Moreover,an increase in the inclination angle simultaneously reduces the effects of density and permeability on reservoir flow,potentially due to a decrease in the number of intersections between natural and hydraulic fractures.On the one hand,the results deepen the scientific understanding of the potential connection between different combinations of natural fracture charac-teristics and reservoir seepage;on the other hand,the described laws of the influence of natural fracture charac-teristics are of great significance for the design of hydraulic fracturing construction programs and the enhance-ment of reservoir production.
shale gas reservoirhydraulic fracturesfluid-solid couplingnatural fracturesnumerical simulation
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