中文摘要：

页岩气渗流模型是页岩气藏动态分析和数值模拟的基础。将裂缝性页岩气藏视为基质孔隙一裂缝双重介质，同时考虑岩石骨架变形对气体渗流场的影响，建立页岩气藏流固耦合渗流模型。模型假设基质孔隙内作克努森流动，裂缝中作达西渗流，综合考虑页岩气壁面滑脱流动与孔内扩散作用、吸附与脱附、应力敏感性等渗流机制。采用有限元法离散控制方程及全隐式耦合求解方法，编制计算机程序。考虑真实页岩参数取值，利用该模型进行算例分析。结果表明，页岩气藏压力下降速率小于常规裂缝性气藏压力下降速率；裂缝渗透率是影响裂缝渗流压力衰减的主要因素，需考虑页岩裂缝导流能力与基质产气速率的匹配关系；原始地层压力越小，裂缝渗流压力衰减越慢。所建模型可为页岩气藏模拟器开发及动态分析提供理论基础。

英文摘要：

A comprehensive gas-flow model for shale gas reservoir is significantly important for the dynamic analysis of gas production and reservoir simulations. This paper proposed a hydro-mechanical model for shale gas reservoir that was considered as dual permeability media of matrix pore and fracture. The Knudsen flow in porous matrix and Darcy flow in fracture network were assumed. The model involves multiple flow regimes, gas adsorption/desorption, and stress-sensitive effect. Finite element method was used to discretize the governing equations by fully implicit discretization schemes, and thus corresponding code was made. A numerical example was presented using the proposed model and field shale parameters. Results show that the pressure-declined rate of shale gas reservoir is less than that of conventionally fractured reservoirs. Fracture permeability is a primary factor of reservoir pressure depletion. It is necessary to make the flow conductivity of fractures match with the gas production from shale matrix. The initial pressure has a major effect on the fracture pressure depletion, which indicates that the less initial pressure is, the less fracture pressure depletion is. The presented model and code are helpful for understanding shale gas production and developing the shale-gas reservoir simulator.