CO 2 Foam Behavior in Carbonate Rock: Effect of Surfactant Type and Concentration

High Resolution Image Download MS PowerPoint Slide An understanding of how CO 2 foam flows through a reservoir rock is useful for many subsurface applications, including enhanced oil recovery and CO 2 storage. There are economic and environmental benefits in identifying surfactants that exhibit good foaming behavior with CO 2 at both low concentrations and high foam qualities. Core flood experiments have been carried out to investigate the behavior of supercritical CO 2 foams flowing through a high-permeability Indiana Limestone. The foaming behavior and concentration response of two surfactants, a betaine and a sultaine, were investigated. For the two surfactants, the transition foam quality and the maximum apparent foam viscosity both decreased with reducing surfactant concentration. A comparison between the foaming behaviors of these surfactants with CO 2 and N 2 was also carried out. It was found that the N 2 generated stronger foam at low foam qualities, but the CO 2 was better at maintaining good foaming behavior at high foam qualities.