Experimental Study of Anisotropic Characteristics of a Specific Formation Shale

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.