Mobility and Conformance Control for Carbon Dioxide Enhanced Oil Recovery (CO2-EOR) via Thickeners, Foams, and Gels – A Detailed Literature Review of 40 Years of Research
R.M. Enick and D.K. Olsen
Final Report, DOE/NETL-2012/1540. Contract DE-FE0004003 Activity 4003.200.01
Carbon dioxide (CO2) has been used commercially to recover oil from geologic formations by
enhanced oil recovery (EOR) technologies for over 40 years. The U.S. Department of Energy
Office of Fossil Energy and its predecessor organizations have supported a large number of
laboratory and field projects over the past decades in an effort to improve the oil recovery
process including investments to advanced reservoir characterization, mobility control, and
conformance of CO2 flooding.
Currently, CO2 EOR provides about 280,000 barrels of oil per day, just over 5 percent of the
total U.S. crude oil production. Recently CO2 flooding has become so technically and
economically attractive that CO2 supply, rather than CO2 price, has been the constraining
developmental factor. Carbon dioxide EOR is likely to expand in the United States in upcoming
years due to “high” crude oil prices, natural CO2 source availability, and possible large
anthropogenic CO2 sources through carbon capture and storage (CCS) technology advances.
This literature review concentrates on the history and development of CO2 mobility control and
profile modification technologies in the hope that stimulating renewed interest in these chemical
techniques will help to catalyze new efforts to overcome the geologic and process limitations
such as poor sweep efficiency, unfavorable injectivity profiles, gravity override, high ratios of
CO2 to oil produced, early breakthrough, and viscous fingering. Carbon dioxide mobility control
technologies are in-depth, long-term processes that cause CO2 to exhibit mobility comparable to
oil. Profile modification and conformance control are achieved by a near-wellbore, short-term
process primarily intended to greatly reduce the permeability of a thief zone.
The premise of this report is that a thorough review of the literature related to the past successes
and failures of lab- and field-scale efforts to reduce CO2 mobility using CO2 thickeners, foams,
and gels will provide a baseline understanding of the remaining challenges and the research
needed to advance this technology. Solving these challenging CO2 flooding problems will
ultimately increase domestic oil production via CO2 EOR. This review has highlighted a number
of successes.
