Experimental Study on the Effect of Bedding on the Fracture Process Zone of Shale

The conventional fracture in shale hydraulic fracturing belongs to the type-I fracture, and size of process zone (FPZ) is an important index measure fracability rock mass. This also one feasible entry points study complexity network. In order visually observe FPZ at tip fractures, relationship between mechanical properties, shape FPZ, bedding structure, Notched Semi-Circular Bend (NSCB) tests were conducted with three typical direction-bedding orientations (splitter, arrester, divider). digital image correlation (DIC) method was used realize intuitive observation real near tip. test found that narrow long as a whole “flame-like”. height-to-length ratio determines whether bending deflection happen new prefabricated cracks when occurs. Most specimens often appear beaded high shear strain before which caused by oblique communication micro-cracks fracture. appearance indicates macroscopic imminent. research results can be for design disaster early warning prevention programs.