Evaluation of CO2 Storage Resources and Costs for the United States

Abstract

The carbon capture and storage (CCS) project design requires the proper selection of CO2 storage sites in terms of storage resources (or capacities) and costs from those hundreds and thousands of available sites. Conventional analytical approaches and numerical flow simulations are capable of providing evaluations, but they suffer from low accuracy and high computational cost, respectively. Therefore, to address this challenging problem, we focus on developing advanced tools for evaluating nationwide CO2 resources and costs in the United States. Specifically, we leveraged machine learning algorithms to build reliable and fast proxy models for predicting CO2 injectivities and the dynamic areas of CO2 plume, which were then integrated into our recently updated open-source CO2 storage resource evaluation tool SCO2T for performing a large-scale evaluation of CO2 storage resources in the U.S. Our result indicates that the trained proxy models for the predictions of CO2 injectivities and CO2 plume areas are reliable, as the forecasted quantities of interest closely match those obtained from flow simulations. We applied the proxy-assisted SCO2T model to assess over 300 major formations in the U.S. for a national-scale evaluation of CO2 storage potential. Our findings revealed significant variations in CO2 storage capacities and costs across the U.S. For instance, some storage sites present as favorable candidates due to their low cost and substantial storage resources (e.g., in the Gulf Coast region). However, some storage sites are less preferable due to high costs, limited storage capacity, or both. For example, several formations in the northeastern U.S. have extremely high costs but low storage capacity. However, due to biases and limitations in the dataset used, this evaluation study may not capture real-world scenarios and should not serve as a guide for the future deployment of CO2 injection projects.

Keywords: Carbon capture and storage, CO2 storage, CO2 injection, CO2 resources, Cost evaluation