Probing the micro-mechanics and thermal expansion coefficients of granite's rock-forming minerals

Hydraulic fracturing is typically adopted to enhance permeability by creating a large contact area between the fluids and the hot rock. Thermal cracking will occur due to cold fluid injection near the wellbore and along the primary hydraulic fracture surface. However, the associated micro-crack initiation and propagation mechanisms in heterogeneous crystalline rocks are still unclear. This study addresses the micro-crack initiation and propagation of poly-crystalline granite. The mechanical properties of granite are estimated using homogenization methods based upon the micro-scale mechanical properties and thermal expansion coefficients of major rock-forming minerals as well as its micro-structural information.