Patent ID: 7789144

Claim:
A method 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 includes one or more anionic surfactants; 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, wherein the one or more anionic surfactants is selected from the group consisting of formulas (I), (II), and (III): ROSO 3 − (I) RSO 3 − (II) RC 6 H 4 —SO 3 − (III) wherein R represents an alkyl, alkenyl, arylalkyl, or hydroxyalkyl group; wherein R has about 16 to about 24 carbon atoms; wherein R is saturated or unsaturated, branched or straight chained; and wherein branched alkyl groups have from 1 to about 6 carbon atoms.