The rock mechanical properties and fracability of a shale reservoir play an important role in the development of shale oil and gas. There is limited literature on the rock mechanical properties and fracability of continental shale. The mineral composition, compressive strength, Young's modulus and Poisson's ratio of the continental shale in the Shahejie Formation in the Zhanhua Sag were measured by X-ray diffraction and rock mechanical tests under different maturities and confining pressures. The content of carbonate minerals in the shale is the largest, with an average of 44.93％. The content of brittle mineral is slightly higher than that of clay mineral, Which is 30.98％ and 24.09％, respectively. The failure mode of shale is predominantly splitting under uniaxial compression, which easily forms a fracture network. With additional confining pressure, the failure mode changed to shear mode. The compressive strength, Young's modulus and Poisson's ratio all increased with the increase of confining pressure, but the fracability decreased. The fracability of shale is positively correlated with thermal maturity. By considering mineral composition, mechanical properties, diagenesis and confining pressure, a mathematical model of the fracturing coefficient was established to evaluate the fracability of shale reservoir, which can provide a reference for the selection of fracturing layer.%页岩储层的岩石力学性质与可压裂性对页岩油气的开发具有重要影响.目前对于陆相页岩的岩石力学特征和可压裂性方面的研究较少.利用X射线衍射和岩石力学实验等方法,测试沾化凹陷沙河街组陆相页岩全岩矿物组分、在不同成熟度、不同围压条件下的抗压强度、杨氏模量和泊松比等力学参数,并且对页岩储层的可压裂性进行了分析.页岩矿物成分主要为碳酸盐矿物,平均为44.93％,脆性矿物含量稍高于黏土矿物,分别为30.98％和24.09％;单轴压缩时页岩多为劈裂式破裂,易形成缝网;加围压后破坏形式变为剪切式,抗压强度、杨氏模量和泊松比均增大,可压裂性降低;页岩可压裂性与加热温度,即热成熟度呈正相关.综合考虑页岩矿物成分、力学性质、成岩作用和围压等因素,建立可压裂系数数学模型,可对页岩储层的可压裂性进行定量评价,为压裂选层提供依据.
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