Abstract
Deep saline aquifers are considered as attractive hosts for geological CO2 storage (GCS). The Western Canada Sedimentary Basin (WCSB) comprises numerous saline aquifers. Depending on formation geochemistry, in-situ conditions, and petrophysical properties, each formation will have different storage capacity and efficiency. There are currently 25 proposed projects in the province of Alberta that, if they were all approved with pore space tenure, would inject large volumes of CO2 at relatively large rates into the WCSB. The goal of this study is to present characterizations of potential storage formations and examine the potential for interactions between proposed projects in proximity.
We use numerical and analytical simulation to assess the evolution and interaction of pressure fields from proposed projects over time in the Wabamun Area CO2 Sequestration Project (WASP) region and infer how this affects cumulative storage capacity in the target formations. We compare the result from simple, relatively easy-to-use analytical tools against numerical simulation results to determine whether existing screening tools could accurately capture potential interactions between proximal projects. The results reveal that with increasing length of injection years, the radial extent of the CO2 pressure distribution increases as well. The analytical solution cannot accurately capture formation compressibility and variation in fluid properties, which leads to deviations from the simulated values. Nonetheless, these tools could serve as a quick method to identify areas of concern, and both can provide useful information about the likely extent of the pressure plume in a GCS project.
