中文摘要：

水力压裂法是页岩气开采的主要方法,研究甲烷气通过页岩粗糙裂隙对页岩气的开采具有重大的实际意义。在不同气体压力梯度和围压1-10 MPa条件下,研究CH4通过页岩粗糙裂隙的渗透特性,研究表明：（1）在应力–渗流耦合条件下,页岩粗糙裂隙的导流能力相比其他类型的岩石更差。（2）气体流量与压力梯度并非严格的线性增长关系,其增长速率随着围压的增大而降低,气体通过页岩粗糙裂隙的渗流属于非线性流。（3）围压增大,气体流量和渗透率降低,当围压超过4.0 MPa时,裂隙趋于最大闭合量,流量趋于平稳;（4）压力梯度和流量遵循Forchheimer方程,围压增大,导致孔隙结构和流体性质发生变化,渗流更偏向于线性流;（5）根据工程实际,以10%的非线性流效应为临界,得到本试验条件下的临界雷诺数。

英文摘要：

Hydrofracturing method is the main technique of shale gas exploitation. Researching the methane through rough shale fractures is of great practical significance in this field. In this work,experiment of CH4 through rough shale fractures was investigated under different gas pressure gradients and confining pressures from 1 to 10 MPa. The main results are shown as follows. The fracture conductivity of shale is lower than that of other rocks. The values of flow rate do not strictly follow a linear trend with pressure changes,and the growth rate decreases with the increase of confining stress, indicating that gas through rough shale fractures is non-linear flow. The effective stress increases with the increase of confining stress. While the hydraulic aperture,flow rate and permeability follow the opposite trend. When the confining pressure exceeds 4.0 MPa,the fracture closure reaches the maximum,and the flow rate keeps stable. Forchheimer equation provides a good description for the non-linear fracture flow process. When confining pressure increases,the pore structure and fluid property changed,and the seepage prefers to the linear flow. According to the engineering practice,critical Reynolds number was determined when 10% of nonlinear effect was considered.