Laboratory Simulation of Injection-Induced Shear Slip on Saw-Cut Sandstone Fractures under Different Boundary Conditions

It is widely acknowledged that induced earthquakes may be linked to the fluid mass injection into subsurface in a manner of reactivating preexisting natural faults. To better understand potential effect tectonic boundary conditions on fault slip behavior, we performed injection-induced shear experiments critically stressed saw-cut sandstone samples under constant piston displacement (CPD test) and stress (CSS at confining pressure 10 MPa 15 MPa, respectively. In response low pressurization rate 0.1 MPa/min, artificial fractures (faults) show slow velocity (< ?m/s) accompanied by linear drop CPD tests, whereas faster 5 larger distance are observed subsequent CSS tests. Our experimental results indicate laboratory slide stably overpressure during two supported experimentally measured rate-and-state frictional parameters stability analysis. As applied increases from considerable decrease hydraulic diffusivity. Also, heterogeneity found affected tests both pressures. We interpret this as result local depressurization potentially occurs far away end due rapid shear-enhanced dilation. addition, complete energy budget components associated with fluid-induced fracture context respectively, have been quantitatively evaluated. observations highlight behavior closely related not only effective normal stress, but also conditions.