The bedding surfaces of shale in the Longmaxi formation are well developed. To study the influence of bedding surfaces on the mechanical properties of shale, we have carried out uniaxial and triaxial compression tests on shale specimens of Longmaxi formation in Southern Sichuan, China. The results shows that when the samples are subjected to compression, the properties of shale, including strength characteristics, elastic parameters, and fracture mode in the shale samples, are characterized by strong anisotropy. The confining pressure effect is due to the existence of well-developed bedding surfaces in shale. The results provide a theoretical basis for horizontal wellbore stability analysis and hydraulic fracturing design in shale gas wells.

中文翻译：

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特定地层页岩各向异性特征试验研究

龙马溪组页岩层理面发育。为了研究层理面对页岩力学性质的影响，我们对四川南部龙马溪组页岩标本进行了单轴和三轴压缩试验。结果表明，当样品受到压缩时，页岩样品的强度特征、弹性参数和断裂模式等性质具有较强的各向异性。围压效应是由于页岩中存在发育良好的层理面。研究结果为页岩气井水平井筒稳定性分析和水力压裂设计提供了理论依据。