Development of Geostatistical Models to Estimate CO2 Storage Resource in Sedimentary Geologic Formations

Carbon capture and sequestration (CCS) is a technology that provides a near-term solution to reduce anthropogenic CO2 emissions to the atmosphere and reduce our impact on the climate system. Assessments of carbon sequestration resources that have been made for North America using existing methodologies likely underestimate uncertainty and variability in the reservoir parameters. This thesis describes a geostatistical model developed to estimate the CO2 storage resource in sedimentary formations. The proposed stochastic model accounts for the spatial distribution of reservoir properties and is implemented to a case study of the Oriskany Formation of the Appalachian sedimentary basin. The developed model allows for estimation of the CO2 sequestration resource of a storage formation with subsequent uncertainty analysis. Since the model is flexible with respect to changing input parameters and assumptions it can be parameterized to calculate the CO2 storage resource of any porous subsurface unit. The thesis continues with evaluation of the cost of CO2 injection and storage for the Oriskany Formation utilizing storage resource estimates generated by our geostatistical model. Our results indicate that the cost of sequestering CO2 has significant spatial variation due to heterogeneity of formation properties and site geology. We identify the low-cost areas within the Oriskany footprint. In general, these areas correspond to the deepest portions of the Appalachian basin and could be considered as potential CO2 injection sites for CCS industrial scale projects. Overall, we conclude that significant improvement can be made by integrating basin geology and spatial heterogeneity of formation petrophysical properties into CCS cost assessments, and that should be a focus of future research efforts. This will allow for more accurate cost estimates for the entire CCS system and identify areas of sedimentary basins with optimal conditions for CO2 injection and storage. To mitigate the effects of climate change, the U.S. will need a widespread deployment of low-carbon electricity generating technologies including natural gas and coal with CCS. More precise CO2 storage resource and CCS cost estimates will provide better recommendations for government and industry leaders and inform their decisions on what greenhouse gas mitigation measures are the best fit for their regions.