FEM Simulation of Fault Reactivation Induced with Hydraulic Fracturing in the Shangluo Region of Sichuan Province

Abstract

Hydraulic fracturing operations possess the capacity to induce the reactivation of faults, increasing the risk of fault slip and seismic activity. In this study, a coupled poroelastic model is established to characterize the distribution and movement of fluids within rock formations in the Shangluo region of Sichuan province, China. The effect of hydraulic fracturing projects on the variations of pore pressure and Coulomb effective stress within a high-permeability fault is analyzed. The potential fault-slip mechanism is investigated. The results show that the fault plays different roles for fluid movement, including the barrier, fluid transport channel, and diversion channel, which is related to injection–production schemes. In addition, fluid injection leads to a high probability of fault reactivation. We find that increasing the injection time and fluid injection rate can result in larger slip distances. The injection production scenarios influence the fault-slip mechanism, resulting in a normal fault or reverse fault. However, the arrangement of production wells around the injection can effectively reduce the risk of fault reactivation.

Keywords

• fluid–solid coupling
• Coulomb failure stress
• hydraulic fracturing
• seismic simulation
• fault slip