Developing a roadmap for carbon capture, and storage in Oklahoma by assessing the viability of stacked storage

The Intergovernmental Panel on Climate Change concludes that CO2 capture and storage (CCS) is critical for climate‐stabilizing energy transitions. In CCS, captured CO2 is sequestered in saline aquifers within sedimentary basins. The CO2 storage capacity and the rate of injection are functions of the geology of the saline aquifer, which is uncertain. To minimize impacts of this uncertainty, CCS projects could include backup plans, such as co‐locating geologic CO2 storage (GCS) sites with or near existing CO2‐enhanced oil recovery (CO2‐EOR) operations. These “stacked storage” projects could hedge against uncertainty in the saline formation performance because captured CO2 could be injected into either location in the event of unexpected events (e.g., the injectivity decreases). Here, we investigate the possibility and ramifications of developing CCS networks in Oklahoma that are amendable to stacked storage. We find that stacked storage is possible in Oklahoma but the counties with the lowest‐cost saline storage resources do not have existing CO2‐EOR operations. At the systems level, we find it is slightly more expensive (e.g., $1/tCO2 to $5/tCO2) to site GCS in counties with CO2‐EOR projects. This increased expense is largely due to increased CO2 transportation costs because hundreds of km of additional pipeline is required to capture CO2 from the lowest‐cost sources. Overall, our results suggest that it is optimal to build more pipelines and avoid injecting CO2 in some of the lowest‐cost saline storage resources, to enable capturing CO2 from the least‐cost sources. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.