Eugene Holubnyak, Oluwole Okunromade, Jennifer Raney, Edward Peltier, Kansas Geological Survey
Carbon dioxide enhanced oil recovery (CO₂-EOR) has proved an economically viable option for boosting oil and gas production while combating global warming by sequestering CO₂ in geological formations. In Kansas, many mature oil fields are currently in the late stage of water injection, making them good candidates for CO₂-EOR. Paper and scanned PDF reports exist that detail waterflood performance and reservoir conditions. These reports were obtained at the Kansas Geological Survey library and converted into a digital dataset. This paper provides a preliminary assessment of this dataset. It offers an initial discussion about selection criteria for fields that could be suitable for CO₂-EOR in the future if economic conditions are suitable. This assessment is performed by applying cutoff parameters such as reservoir depth, oil gravity, cumulative oil production, and CO₂ miscibility. From the analysis, about 104 oil fields are determined to be favorable candidates for CO₂-EOR. Selected fields are classified based on CO₂ miscibility potential, which occurs at field depth greater than 3,000 feet. Up to 139 million metric tons of CO₂ can be stored in four oil fields: Spivey-Grabs-Basil, Wellington, Cutter, Plainville, and Seydel. Geochemical analyses using PHREEQC, show that produced water from the Arbuckle formation located in the Central Kansas Uplift basin showed the highest potential of storing CO₂ through solubility trapping due to its relatively low salinity.
For the DOE-sponsored regional assessment study, KGS has also performed geological modeling and numerical simulations estimating CO₂ storage capacity on several prominent EOR targets in western Kansas. The results of regional assessment modeling and estimations based on the state-wide database of waterfloods are compared, and a more realistic number of up to 90 million metric tonnes of CO₂ storage capacity via EOR is estimated for oil fields in Kansas.