Geomechanical simulation of microseismic events induced by CO2 injection at in Salah, Algeria

We have developed a geomechanical workflow to simulate (micro)seismicity induced by reservoir deformation. We use a structural model to simulate the position, orientation and size of fracture networks in a reservoir. We use a geomechanical model to simulate effective stress changes throughout the reservoir as response to injection/production. Stress changes are then resolved into normal and shear stresses on the modelled fractures, allowing us to simulate when and where fractures begin to slip, triggering a microseismic event. We simulate event positions, timing, stress drop and fracture length (from which event magnitude is determined) and source mechanism. These parameters can then be groundtruthed with observations from the field. We apply our workflow to the In Salah CCS project, Algeria. We find good agreement between our simulated microseismic events and observations from the field, both in terms of the rate of microseismic activity through time, event positions, and event magnitudes.