THE BASAL AQUIFER PROJECT: A CANADA-UNITED STATES COLLABORATION FOR GEOLOGICAL CHARACTERIZATION AND MODELING OF A MAJOR DEEP SALINE-AQUIFER IN THE ALBERTA AND WILLISTON BASINS FOR CO2 STORAGE

Carbon dioxide capture and storage in geological media is a near-term approach that can significantly reduce atmospheric emissions of anthropogenic CO₂. Various CO₂ storage studies have been initiated to estimate CO₂ storage capacity in Canada and the U.S., and to evaluate the fate and effects of the stored CO₂. No studies to date have attempted to characterize the storage potential of deep aquifers that span the Canada-U.S. border, and characterize the effects (both geochemical and pressure-induced) such storage might have on groundwater aquifers. The Basal Aquifer project is the first such attempt by targeting the lowermost Cambro-Ordovician saline-aquifer system in the Northern Plains – Prairie Region of North America (~ 1,348,300 km²) that lies directly on the crystalline Precambrian basement in the Alberta and Williston basins. The geological characterization and modeling of CO₂ injection in this aquifer forms the subject of a three-year, bi-national, multi-province/multi-state, multi-organizational and multi-disciplinary project that has been initiated by Alberta Innovates – Technology Futures and the Energy and Environmental Research Center at the University of North Dakota. Trans-boundary collaborations of this nature, however, do not come without challenges, which presently include discrepancies in hydrocarbon well-data reporting and type, differing stratigraphic nomenclature across the provinces and across the Canada/U.S. border, and differences in policy, approach and methodology for characterization of CO₂ storage targets. Overcoming these challenges presents an exciting opportunity, as the potential to mitigate greenhouse gas emissions by sequestering CO₂ in this aquifer is considerable – preliminary results show a storage capacity of 142 Gt CO₂. Furthermore, from a source-to-sink perspective, more than 40% of Canada‘s large CO₂ emitters producing close to half of total Canadian emissions are located in the Prairie region. Similarly, 39 large CO₂ sources are found in the southern half of the Williston Basin in the U.S. This paper will present results obtained to date in characterizing this aquifer for CO₂ storage and in overcoming challenges inherent in working on an area covered by two countries and several sub-national jurisdictions.