Propagation and characterization of the micro cracks induced by hydraulic fracturing in shale

Hydraulic fracturing is commonly used for the exploitation of shale gas. However, the mechanism of permeability increase after the fracturing has still remained unclear so far. In this study, a hydraulic fracturing experiment was performed on Longmaxi shale specimens in order to create the hydraulic fractures. In order to investigate the cracks at micro-scale, several small slices were collected from the fractures surface and scanned with the...