CO2 Applications - Discussion and Reply

Abstract

Discussion and Reply Editor's note: Several readers responded to the Technology Focus article on CO2 Applications written by Sam Gomersall, director of CO2DeepStore, that appeared in the July issue. Excerpts from some of those letters, along with a reply from the author, follow. Discussion Ronald T. Evans, SPE, Denbury Resources, writes: In the Technology Focus article on CO2 Applications (July 2009 JPT, p. 68) the ultimate conclusion that "Enhanced oil recovery (EOR) … is not a CO2-abatement technique" fails to assess CO2 EOR accurately. CO2 EOR projects that use anthropogenic CO2 have the ability to sequester more CO2 than the oil produced will ultimately release. According to the US Department of Energy's National Energy Technology Laboratory (NETL), CO2-EOR projects sequester up to 70% of the CO2 that will ultimately be released by the oil. This report is based on west Texas, water-alternating-gas CO2 EOR projects that inject 5 to 6 Mcf of CO2 for each barrel of oil produced. The report discusses "Next-Generation CO2-EOR Technologies" that have the capacity to inject as much as 160% of the CO2 ultimately released by the oil. Continuous-injection CO2-EOR projects inject 10 to 12 Mcf of CO2 to produce each barrel of oil. Continuous-injection CO2-EOR projects have the capacity to sequester significantly greater CO2 volumes than the oil releases when consumed. Not only does CO2 EOR with anthropogenic CO2 have an important role to play in energy security, it is a significant CO2-abatement technique. It is the only carbon-capture/sequestration (CCS) method that can be conducted today, and it is the only CCS method that produces additional domestic energy and economic benefits while sequestering CO2. For additional reading material, please see: CO2 Enhanced Oil Recovery. World Resources Institute, www.wri.org/publication/content/8355. Tapping into Stranded Domestic Oil: Enhanced Oil Recovery with Carbon Dioxide is a Win-Win-Win. Natural Resources Defense Council, www.nrdc.org/energy/eor.pdf. Storing CO2 with CO2 enhanced oil recovery. US National Energy Technology Laboratory, www.netl.doe.gov/energy-analyses/pubs/Storing%20 CO2%20w%20EOR_FINAL.pdf.