Implications of permeability uncertainty within engineered geologic fluid systems

Carbon-capture and sequestration (CCS) in geologic reservoirs is one strategy for reducing anthropogenic CO2 emissions from large-scale point source emitters. Recent developments have shown that basalt reservoirs are highly effective for permanent mineral trapping on the basis of CO2-water-rock interactions, which result in the formation of carbonate minerals. However, the injection of super-critical CO2 into the subsurface causes a disturbance in the pressure, temperature, and chemical systems within the target reservoir. How the ambient conditions change in response to a CO2 injection ultimately affects the transport and fate of the injected CO2. Understanding the behavior and transport of CO2 within a geologic reservoir is a difficult problem that is only exacerbated by heterogeneities within the reservoir; for example, permeability can be highly heterogeneous and exhibits significant control on the movement of CO2. This work is focused on constraining the permeability uncertainty within a flood basalt reservoir, specifically the Columbia River Basalt Group (CRBG). In order to do so, this dissertation is a culmination of four projects: (1) a geostatistical analysis resulting in a spatial correlation model of regional scale permeability within the CRBG, (2) a Monte Carlo-type modeling studying investigating the effects that permeability uncertainty has on the injectivity and storativity of the CRBG as a storage reservoir, (3) a modeling study utilizing 1-, 2-, and 3-D numerical models to investigate how the thermal signature of the CO2-water system evolves during a CO2 injection, and (4) a Monte Carlo-type modeling study focused on the integrity of the CRBG as a CO2 storage reservoir through a probabilistic assessment of static threshold criteria.