中文摘要：

储层岩体中的天然结构面对水力压裂缝网改造具有重要的影响。本文采用真实破裂过程分析软件RFPA2D-Flow，在考虑岩体非均质性和岩体渗流-应力-损伤破裂特性的基础上，对不同尺度天然结构面影响的水力压裂裂缝扩展与演化行为进行了模拟分析和讨论，研究结果表明：（1）当水力裂缝遇天然非闭合裂隙时，在水力裂缝靠近非闭合裂隙区间形成拉张应力区，水力裂缝与区间非闭合裂隙间微元体累进性张拉破坏是导致水力裂缝与非闭合裂隙贯通的主要机制；（2）层理等优势结构对水力压裂裂缝扩展及缝网形态影响十分显著，当最大主应力方向与层理面走向小角度相交时，层理结构面对水力裂隙的扩展起主要作用，当最大主应力方向与层理面走向大角度相交时，最大主压应力与层理面共同对缝网扩展起主导作用，随着优势结构面的增多和差应力的增大，水力压裂形成的缝网范围和复杂性程度随之增大；（3）储层水力压裂是一种局部范围内的短暂动力扰动过程，尽管断层的存在可以极大地影响水力裂缝的扩展模式，增大水力裂隙扩展高度，但相比于储层埋深，水力压裂对断层封闭性的破坏范围和断层活动性的扰动程度十分有限。

英文摘要：

In shale gas reservoirs, natural rock mass structural planes usually have significant influences on hydraulic fracturing treatment. This study uses the RFPA2D-Flow program. It considers the coupling seepage-stress-failure process of crack initiation, propagation, and damage. It simulates hydraulic fracturing process of rock mass in heterogeneous rock mass with different scales of natural structural planes. Though numerical simulation and discussion, the main conclusions can be drawn as follows：（1） When a hydraulic fracture encounters a natural unclosed crack, the principal stress trajectories would be deflected and a tensile stress zone would be created between the hydraulic fracture and the natural crack due to the increased pore pressure and propagation of the hydraulic fracture. Thus, the emergence and coalescence of tensile failure of the micro-units eventually causes the connection between the hydraulic fracture and the natural crack.（2） Bedding planes have pronounced effects on hydraulic fracturing. When the strikes of the maximum principal stress and the bedding planes intersect at a small angle, the bedding planes control the propagation of the hydraulic fractures. Otherwise, both the maximum principal stress and the bedding planes dominate the expansion of the fracture network. In addition, with the increase in structural planes and differential stresses, the scope and complexity of the stimulated fracture network increase simultaneously.（3） Hydraulic fracturing treatment is a short dynamic damage process. Although the existing of a fault structure can greatly affect the propagation model of the hydraulic fracturing and enhance the growth height of the hydraulic fracture, the damage to fault sealing capacity and activity caused by hydraulic fracturing is still limited compared with the depth of the reservoir.