Patent ID: 7779913

Claim:
A method for flooding an oil-bearing reservoir, comprising: a) introducing a flooding fluid into the reservoir, wherein the fluid has: i) water; and ii) an amount of one or more non-polymeric, viscoelastic surfactants sufficient to provide the flooding fluid with an oil/water interfacial surface tension of about 1 mN/m or less and a viscosity of about 10 cPs or more, wherein the one or more non-polymeric, viscoelastic surfactants is selected from the group consisting of one or more cationic surfactants, one or more zwitterionic surfactants, one of more anionic surfactants, one or more amphoteric surfactants, and combinations thereof; iii) and carbon dioxide; wherein the fluid is in the form of a supercritical carbon dioxide emulsion; and b) pushing oil through the reservoir to the vicinity of a wellbore at a location different than the point of introduction of the flooding fluid into the reservoir; and c) extracting the oil through the wellbore.