DSSS: Improving CO2 Enhanced Oil Recovery with CO2-soluble Additives, with Possible Application to CO2 Sequestration
- Who: Bob Enick, Ph.D., University of Pittsburgh
- What: Download the Flyer (pdf)
- Where: Building 66 Auditorium, hosted by Shibo Wang
- When: 10:30 am to 12:00 noon, September 19, 2014
- Why: About the Distinguished Scientist Seminar Series
Bob Enick has been a professor of chemical and petroleum engineering at the University of Pittsburgh since 1985. He has been a fellow at the National Energy Technology Laboratory since 1987, where he investigated enhanced oil recovery, geologic sequestration, high pressure phase behavior and viscometry, the design of pre-combustion CO2 solvents, and CO2- or H2-permeable membranes. He was a part of the 2002 team that won the Presidential Green Chemistry Challenge Award for pioneering the design of non-fluorous CO2-philic compounds. He was also part of the group that received the 2011 US Secretary of Energy’s Achievement Honor Award for quantifying the rate of the oil flow from the Macondo blowout into the Gulf of Mexico. Most of his recent work has been directed at improving the performance of CO2 enhanced oil recovery and the use of liquid CO2 as an alternative to water-based hydraulic fracturing fluids.
During the past 40 years, several prolific natural subterranean reservoirs of high pressure CO2 have served as the primary sources of the CO2 that is transported via pipeline to oilfields for enhanced oil recovery (EOR). CO2 extracted from methane-rich natural gas represents a smaller portion of the CO2 EOR feed stream. In the future, CO2 obtained from carbon capture processes may provide a massive new source of CO2, a portion of which could be purchased by EOR operators.
Over 3,000,000,000 standard cubic feet of CO2 is injected into sandstone and carbonate reservoirs every day, resulting in the daily production of nearly 300,000 barrels of oil. At the end of the project, a large volume of CO2 remains sequestered in the porous formation. Although most CO2 EOR projects are economic successes, a very large fraction of the oil in the reservoir remains unrecovered. The primary culprit responsible for this disappointing oil recovery is the very low viscosity of high pressure CO2; it is typically 10-100 times less than the viscosity of the oil being displaced. This causes the CO2 to finger through most of the formation and bypass most of the oil.
In this talk, we will review strategies for dealing with this problem, focusing on novel CO2-soluble additives that can increase the viscosity (or apparent viscosity) of CO2. A CO2 thickener would be a disruptive technology, yet an affordable CO2 thickener has eluded researchers for 30 years; it remains the most perplexing scientific challenge associated with CO2 EOR. Other additives for improving the flow of CO2, such as CO2-soluble surfactants, brine-soluble surfactants, and brine-dispersible nanoparticles, will also be discussed. We will also consider the possible use of CO2-soluble compounds during sequestration to improve the placement of CO2 or to stop CO2 leakage from the porous medium.