A simple but rigorous model for calculating CO[subscript 2] storage capacity in deep saline aquifers at the basin scale

Abstract

Safely sequestering CO[subscript 2] in a deep saline aquifer requires calculating how much CO[subscript 2] the aquifer can store. Since offsetting nationwide emissions requires sequestering large quantities of CO[subscript 2], this calculation should apply at the large scale of geologic basins. The only method to calculate storage capacity at the basin scale, however, is not derived from multiphase flow dynamics, which play a critical role in CO[subscript 2] storage. In this study, we explain a new model to calculate basin-scale storage capacity that is derived from flow dynamics and captures the dynamic phenomena of gravity override and capillary trapping. Despite the fact that the model is dynamic, it is simple since it is a closed form expression with few terms. We demonstrate how to apply it on the Fox Hills Sandstone in the Powder River Basin.