Union Oil Company of California

June M Bostich

Jeffery W Koepke

Wen-Ching Hsieh

A petroleum sulfonate is prepared by (a) separately sulfonating each of two or more different petroleum fractions boiling substantially above 700.degree. F. by contact with sulfur trioxide under reaction conditions wherein the ratio of milliliters of sulfur trioxide to grams of aromatic components is adjusted so as to produce from each separate fraction a reaction product capable of producing upon neutralization a sulfonate having a sulfonate requirement in microemulsion below about 20 grams per 100 milliliters of microemulsion; (b) separately neutralizing the sulfonated fractions; and (c) blending the hydrocarbon sulfonates produced from two or more of the fractions in proportions sufficient to yield a product petroleum sulfonate blend useful for enhanced oil recovery. In one embodiment four different petroleum fractions are separately sulfonated using different ratios of sulfur trioxide to aromatic content for each fraction and the sulfonated fractions are blended in a weight ratio between 0:1:1:0 and 1:10:10:1 to yield a sulfonate blend useful for enhanced oil recovery.

Process for producing petroleum sulfonates

Enhanced oil recovery from a subterranean petroleum reservoir is realized by successively flooding oil-bearing subterranean formations with (1) a micellar displacement fluid comprising a hydrocarbon, cosurfactant, brine and two or more different petroleum sulfonates, (2) a mobility buffer, and (3) an aqueous drive fluid; the oil is recovered from one or more production wells spaced apart from the injection well in the reservoir.

Growing community of inventors

Brea, CA, United States of America

June M Bostich