CO₂ injection evaluation in the arbuckle formation under thrall-aagard reservoir in Kansas

We used numerical simulation experiments to understand a potential CO ₂ injection site, the Arbuckle formation under the Thrall-Aagard reservoir in Kansas. Including the potential CO₂ plume migration, convective mixing, and drying-out processes, we investigated thermophysical processes associated with CO₂ injection, namely, Joule-Thompson cooling and enthalpy changes associated water vaporization and CO₂ dissolution. Results suggest that the rate of pressure dissipation after stopping injection was rapid in the Arbuckle formation since this formation is hydrologically connected to open surface, the Ozark Plateau aquifer system in Missouri. Consequently, CO₂ densities radically drop with pressure dissipation. In addition, as supercriticalphase CO₂ comes into contact with formation brine, CO₂ will dissolve into this fluid, an exothermic reaction at typical in situ conditions appropriate for CO₂ sequestration. Thus, CO₂ dissolution potentially increases both the enthalpy and temperature of CO₂-laden brine. However, the magnitude of this increase was minor in most cases (less than 1°C). In summary, the detailed understanding of thermophysical properties of CO₂ is necessary prior to field-scale deployment in this site.