(559h) Uncertainty Analysis of Impact of Geochemical Reactions on Forecasting CO2 Storage at a Depleted Oil Field

Carbon dioxide (CO₂) may be sequestered in the subsurface by many trapping mechanisms, including structural trapping, residual and capillary trapping, solubility trapping, and mineral trapping. While these mechanisms are predicated on geological structures and multiphase fluid flow, geochemical reactions between rock and fluids (CO₂ and original fluid in place, e.g., oil and water) also affect permeability and porosity. The impacts of geochemical reactions on CO₂ storage in deep saline formations is still under intense study by the community; however, its impact on CO₂ storage in depleted oil reservoirs remains unclear.

In this study, we quantify the impact of geochemical reactions during and after CO₂ injection. We selected the Morrow B sandstone at the Farnsworth Unit (FWU) enhanced oil recovery with CO₂ (CO₂-EOR) field in northern Texas for this study. Preliminary results suggest that the impacts of reactive transport on altering properties of porous media are insignificant, at least for a 100-year time frame. By conducting additional uncertainty analysis, we are refining the impacts of geochemical reactions on CO₂ storage forecasting with uncertainty in heterogeneity and geochemical environment taken into consideration.