Assessment of CO2 sequestration potential and economics in Colorado, USA

Abstract

Carbon Capture, Utilization, and Sequestration (CCUS) is widely considered essential to mitigating anthropogenic climate change. This study, supported by the regional U.S. Department of Energy (DOE) initiative, Carbon Utilization and Storage Partnership (CUSP), evaluates the potential, progress, challenges, and economics of CCUS in Colorado, USA. We examine carbon capture, transportation, and storage potential in oil and gas reservoirs, saline aquifers, and CO₂-enhanced oil recovery (EOR) operations. Additionally, we conduct an economic analysis and discuss the leakage risks posed by legacy wells, which may impact the safety and security of CO₂ storage. It was found that the nine facilities with the greatest CO₂ emissions in Colorado overlie the Denver-Julesburg (DJ) Basin, and half of these are in the Wattenberg field. The DJ Basin, especially the Wattenberg field, is the top-ranked carbon storage target in Colorado for this reason, as well as because: 1) low-permeability formations (Niobrara and Codell) can be used for enhanced oil recovery, and 2) stacked saline aquifers, such as the Dakota, Entrada, Fountain, Lyons, and Morrison Formations, have a high capacity for carbon storage. Through a refined analysis of the efficiency factor, our study provides more accurate assessments of storage capacity, demonstrating that saline aquifers possess significantly higher carbon storage capacities than oil and gas reservoirs. In the Wattenberg field, simulation studies demonstrate that approximately 18 % of injected CO₂ can be stored over a four-year CO₂-EOR process. Additionally, CO₂-EOR reduces overall CO₂ emissions per barrel of oil by 76 % compared to conventional production methods. Economic analysis indicates that CO₂-EOR is an effective approach to offset the high costs associated with CCUS.