Impact of Reservoir Permeability, Permeability Anisotropy and Designed Injection Rate on CO2 Gas Behavior in the Shallow Saline Aquifer at the CaMI Field Research Station, Brooks, Alberta

Abstract

Carbon capture and storage is part of Canada’s climate change action plan to reduce greenhouse gas emissions. The Containment and Monitoring Institute Field Research Station contributes to scientific and technological progress that ensures the secure underground storage of CO2. In this study, the process of shallow CO2 gas injection (300 m) and subsequent plume development at the FRS was investigated using numerical simulation. Due to reservoir uncertainties, various sensitivity analyses were performed to illustrate their effects on CO2 saturation, plume distribution and CO2 dissolution in a saline reservoir in response to variations in horizontal permeability (kh), kv/kh ratio and CO2 injection rate. The distance of horizontal migration of the plume post-injection was predicted analytically, and the result was validated against the numerical simulation prediction. Results show that increases in kv/kh ratio resulted in increases in both vertical and lateral plume migration and in decreases in dissolution rate and CO2 solubility. It was also indicated that the subsequent post-injection CO2 migration rate was independent of both kv/kh and previous injection rate. Dissolution varied significantly with changes in horizontal permeability. The model shows that increased horizontal permeability facilitated plume migration vertically and horizontally. Modeled permeability variations in horizontal permeability (kh) and kv/kh ratio had a progressively decreasing effect on plume vertical migration with time, while lateral migration effects increased with time.