Patent ID: 7468343
Filing Date: 2008-12-23
Classification: C07C,C09K

Abstract:
1. A method for recovering crude oil from a subterranean hydrocarbon containing formation, which method comprises: (a) injecting into the formation an aqueous solution containing an amount of alkylxylene sulfonate or a mixture of alkylxylene sulfonates effective for the recovery of crude oil wherein the alkylxylene sulfonate has the general formula:  wherein R is an alkyl group containing from about 10 to about 58 carbon atoms, M is a mono-valent cation, and the alkylxylene moiety is alkyl-ortho-xylene in at least 85 percent of the total alkylxylene sulfonate, and wherein the alkylxylene moiety in the alkylxylene sulfonate contains greater than about 70 percent of the 4-alkyl-1,2-dimethyl benzene isomer and the attachment of the alkyl group to the xylene moiety in the alkylxylene sulfonate is at positions higher than the 2-position along the alkyl chain in at least 40 percent of the total alkylxylene sulfonate, and wherein the alkyl group contains a distribution of alkyl chain lengths wherein the alkyl chain lengths comprise from about 40 to about 80 percent C (b) displacing the crude oil with the aqueous solution injected into the formation to thereby recover hydrocarbons from a production well.