EOR III pilot — Sugar Creek Oil Field, Kentucky

This immiscible CO2 pilot is designed to inject CO2 into a prevalent Illinois Basin oil-bearing interval (or equivalent) to directly measure CO2 sequestration mass, enhanced oil recovery, and CO2 injection rate. The Jackson Sandstone, an oil-bearing interval similar to the Cypress Sandstone, was chosen as the target formation. Numerical modeling will be used to assess EOR and sequestration at large scale and update Phase I CO2 storage resource estimates for oil reservoirs.

Injection reservoir depth of 1,850 ft, fine-grained sandstone packages interbedded with shales; lenticular sand bodies, thickness 5–20 ft, fair to poor communication. Permeability 20 mD and average porosity is 16%; there was evidence of faulting in the area, which likely resulted in natural fracturing within the sandstone reservoir.

  • Injected CO2 as a liquid into an existing water injection well converted to a CO2 injection well CO2 – converting to gas in situ
  • Produced fluids from eight wells surrounding the injection well in an area flood
  • Metered and monitored CO2, hydrocarbon gas, oil, and water production; CO2 detected at one well after two weeks of injection, well was shut in due to high GOR

Project status:
  • Completed

CO2 injection results:
  • 7,230 tons cumulative injection
  • 20–30 tons/day injection rate

  • Direct pilot measurements
    • Estimated IOR is 9,900 bbl oil, including
    • Estimated CO2 EOR of 2,700-3,200 bbl
  • Fullfield projections:
    • Estimated potential CO2 storage is 5,800 to 10,500 tons
    • Model results suggest that full-field CO2 injection for 20 years could have 5.5% incremental oil recovery, or 174,000 stb
  • CO2 detected at relatively low rates at five wells
  • CO2 has enhanced oil rate above pre- CO2 rates, oil production was nearly 10 bopd above pre-injection rates, after loss of production from shut-in well
  • Early breakthrough of CO2 results in loss of production adversely affecting direct field measurements of EOR project

Monitoring, verification, and accounting:
  • Conducted baseline, injection, and post-injection monitoring, including continuous in-zone pressure and temperature, cased-hole logging; weekly CO2 casing gas, monthly brine chemistry, quarterly shallow groundwater, and residential well sampling
  • Conducted reservoir, geochemical, and groundwater flow modeling to verify operational and field efforts
  • Monitored CO2 casing gas concentrations and groundwater quality through May 2011, one year after CO2 injection terminated
  • Continued geochemical evaluation and modeling of groundwater quality data

Preliminary MVA results:
  • Groundwater flow model shows regional flow to the northwest and northeast
  • Shallow groundwater quality has not been impacted by CO2 injection activities
  • At some Sugar Creek oil wells, in-zone geochemical monitoring shows significant change in CO2 casing gas and brine chemistry prior to a significant pressure response

Midwest Geological Sequestration Consortium
Midwest Geological Sequestration Consortium
Advanced Energy
Technology Initiative

University of Illinois
615 E. Peabody Dr.
Champaign, IL 61820