Experimental workflow to estimate model parameters for evaluating long term viscoelastic response of CO2 storage caprocks

Understanding the time-dependent behavior of reservoir and sealing formations for geologic carbon storage is critical to assessing geomechanical risks since deformation strongly influences mechanical response some rock types. Many studies have evaluated risk CO2 leakage induced seismicity by assuming poroelastic rheology in formations. Few considered viscoelastic or other responses, much literature on long-term rocks examines only a 1D uniaxial response. This primarily because, date, general form reasonable 3D model remains unclear. In this paper, we propose an approach address using new workflow estimate constitutive modeling parameters evaluation model. The proposed uses power-law extrapolate several-hour-long experimental data decades-long time frames interest storage. Experimental were obtained conducting multi-level loading/unloading triaxial relaxation tests with four different results showed that maximum load observed approximately 49%, types showing as little 1.4%. Using workflow, two linear models, i.e., generalized Maxwell (GM) fractional Kelvin-Voigt (FKV) model, their chosen extrapolated 30-year such deviation from assumed these models was 2 MPa axial stress 7 radial stress. We provided ranges be later used responses. Our also when GM selected analyze here, has range 1–1010 s. scale captures long centuries, which longer than 10–30 years-long frame envisioned injection projects.