Gigaton Commercial-Scale Carbon Storage and Mineralization Potential in Stacked Columbia River Basalt Reservoirs

We present a detailed supercritical CO2 storage resource estimation for the stacked interflow reservoirs in the Grande Ronde Basalt of the Columbia River Basalt Group. This study aims to parametrize subsurface, economic, and regulatory analyses needed to derisk and commercialize geologic carbon storage in continental flood basalts while leveraging rapid mineralization trapping of injected CO2 in basalt. The structural closures provide excellent physical traps to accommodate injected supercritical CO2 and allow for injection at supercritical conditions. We analyzed deep borehole well logs, structural maps, hydrologic test results, and numerical simulations to calculate carbon storage resource for our study area of SE Washington and NE Oregon. Hydrologic testing, well log, and reactive transport simulations from the Wallula Basalt Pilot #1 well provided data for 17 permeable injection zones separated by impermeable aquitards in the Grande Ronde Basalt. This investigation highlights a highly secure pathway to permanent geological CO2 storage for up to 181, 304, or 351 gigatons (P90, P50, and P10, respectively) in only a ~88,000 km2 study area, equivalent to more than 34 years of net U.S. carbon emission. We also discuss these results in the context of carbon mineralization in reactive basalt formations, permitting, commercialization, and storage security.