The Effects of Geomechanical Deformation on Seismic Monitoring of CO2 Sequestration

When CO2 is injected into the subsurface, changes in pore pressure may lead to deformation of both the reservoir and the subsurface. Of concern is that this deformation may create or reactivate fracture networks, providing pathways for CO2 to migrate away from the targeted zone. By coupling a commercial reservoir fluid flow simulator with a finite element geomechanical solver, we model the geomechanical effects of CO2 injection into a simple reservoir. In order to link deformation with changes in seismic observables, a stress dependent rock physics model is outlined and calibrated. We utilize this model to show how injection induced stress changes might be imaged using shear wave splitting.