Influence of gas transport mechanisms on the productivity of multi-stage fractured horizontal wells in shale gas reservoirs

摘要: In order to investigate the influence on shale gas well productivity caused by transport in nanometer-size pores, a mathematical model of multi-stage fractured horizontal wells reservoirs is built, which considers viscous flow, Knudsen diffusion, surface and adsorption layer thickness. A discrete-fracture used simplify fracture modeling, finite element method applied solve model. The numerical simulation results indicate that with decrease intrinsic matrix permeability, diffusion contributions production become large cannot be ignored. existence an nanopore surfaces reduces effective pore radius porosity, resulting low from wells. With radius, considering layer, reduction rate increases. When less than 10 nm, because combined impacts layers, increases pressure. pressure lower 30 MPa, increase becomes larger