Injection‐induced seismicity: Poroelastic and earthquake nucleation effects

Abstract The standard model of injection‐induced seismicity considers changes in Coulomb strength due solely to changes in pore pressure. We consider two additional effects: full poroelastic coupling of stress and pore pressure, and time‐dependent earthquake nucleation. We model stress and pore pressure due to specified injection rate in a homogeneous, poroelastic medium. Stress and pore pressure are used to compute seismicity rate through the Dieterich (1994) model. For constant injection rate, the time to reach a critical seismicity rate scales with t ∼ r 2 /( c f c ), where r is distance from the injector, c is hydraulic diffusivity, and f c is a factor that depends on mechanical properties, and weakly on r…