Mitigating Induced Seismicity Through Active Pressure Management: Simulation-Based Studies

Kayla A. Kroll, Keith B. Richards-Dinger, & Joshua A. White

Published July 20, 2016, SCEC Contribution #6326, 2016 SCEC Annual Meeting Poster #317

The recent upturn of seismicity rates in the Central and Eastern United States and Canada has been attributed to industrial operations such as waste-water disposal, hydraulic fracturing, and subsurface carbon storage. We couple the 3D, physics-based earthquake simulator, RSQSim, to a reservoir model to investigate the space-time characteristics of earthquakes induced by pore-fluid pressure increases and/or poroelastic stresses during injection. RSQSim employs rate-state friction, which gives rise to spatiotemporal earthquake clustering. The simulator generates long catalogs of seismicity based on stress changes due to fault interaction and external stress perturbations with great computational efficiency, allowing for multiple simulations to systematically explore the parameters that control induced seismicity. These simulations provide physics-based statistical data that may contribute to the formalization of optimal injection operations designed to minimize risk of seismicity at a given industrial site.

Industrial operators may modify injection rates as an active seismicity mitigation tool to either reduce the total number of earthquakes or attempt to reduce the likelihood of future large events. To explore the efficacy of this approach, we use RSQSim to explore how sequences of induced earthquakes respond to changes in injection schedule. We simulate induced seismicity on a single optimally oriented fault with fractally distributed initial shear stresses and compare results from models with/without along-strike fault permeability and poroelastic stress changes. We investigate the seismic response to several injection schedules that lie between two end-member scenarios, 1) constant injection at low rates, and 2) periodic injection at high rates. We evaluate the cumulative number of events, total seismic moment release, and the spatio-temporal characteristics of seismicity including the time/location of the next large event after adjusting injection rates.

Prepared by LLNL under Contract DE-AC52-07NA27344.

Citation
Kroll, K. A., Richards-Dinger, K. B., & White, J. A. (2016, 07). Mitigating Induced Seismicity Through Active Pressure Management: Simulation-Based Studies. Poster Presentation at 2016 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Simulators