Abstract
Foam is a promising means to assist in the permanent, safe subsurface sequestration of CO2, whether in aquifers or as part of an enhanced-oil-recovery (EOR) process. Here we review the advantages demonstrated for foam that would assist CO2 sequestration, in particular sweep efficiency and residual trapping, and the challenges yet to be overcome. We also review the research and field-trial literature on CO2 foam sweep efficiency, capillary gas trapping in foam, issues involved in surfactant selection for CO2 foam applications, foam field trials, and the state of the art from laboratory and modelling research on CO2 foam properties, in order to present the prospects and challenges for foam-assisted CO2 sequestration. Challenges to foam-assisted CO2 sequestration include the following: 1) verifying the advantages indicated by laboratory research at the field scale 2) optimizing surfactant performance, while further reducing cost and adsorption if possible 3) long-term chemical stability of surfactant, and dilution of surfactant in the foam bank by flow of water. Residual gas must reside in place for decades, even if surfactant degrades or is diluted. 4) optimizing injectivity and sweep efficiency in the field-design strategy.
Short Bio
George Hirasaki is the A.J. Hartsook Professor Emeritus in the Department of Chemical and Biomolecular Engineering at Rice University. He graduated with a B.S. from Lamar University in 1963 and with a Ph.D. from Rice University in 1967. He was employed by Shell Development and Shell Oil Companies from 1967 to 1993. He joined the Rice faculty in 1993 as Professor.
George received the Ralph Budd Award for the best PhD in Engineering at Rice in 1967. He was inducted into the National Academy of Engineering in 1991. He is a charter member of The Academy of Medicine, Engineering & Science of Texas. He received from the Society of Petroleum Engineering, the Lester C. Uren Award, IOR Pioneer Award, Offshore Technology Conference Heritage Award, and the Anthony F. Lucas Gold Medal. In 1999, he received the Technical Achievement Award of the Society of Core Analysis. He received the Order of the Rising Sun by the Government of Japan in 2009. In 2014, he received the Distinguished Alumni Award of Rice University. In 2022, he received the Engineering Alumni Award of Rice University.