Patent ID: 8163678

Claim:
An enhanced oil recovery formulation comprising (a) a primary surfactant comprising an alkylaromatic moiety having the general formula: wherein R 1 is hydrogen or an alkyl group containing from about 1 to 3 carbon atoms; R 2 is hydrogen or an alkyl group having from about 1 to 3 carbon atoms; R 3 is an alkyl group having from about 8 to about 60 carbon atoms and M is a mono-valent cation; (b) a secondary co-surfactant having the general formula: R 4 —SO 3 X wherein R 4 is an aliphatic hydrocarbyl group having from about 12 to about 40 carbon atoms, and having from about 20 to 98 weight percent branching, and containing one or more olefin or alcohol moieties or mixtures thereof; and X is a mono-valent cation; (c) a solvent; (d) a passivator; and (e) a polymer.