Process for recovering oil from subterranean reservoirs

Abstract

This invention involves a process for recovering oil from a subterranean reservoir where an injection fluid containing one or more primary surfactants of the structure below along with one or more co-surfactants, solvent and optionally a viscosifier and one or more alkalis injected into one or more injection wells and the oil is recovered from one or more producing wells. where: Ar=any aromatic moiety, M=H, Na, K, Ca, Mg, NH4, or an amine, m+n=10 to 28, R, R′, R″=separately and independently H, CH3, branched alkyl having 2-30 carbons, linear alkyl having 2-30 carbons, CH3(CH2)mCH(CH2)nSO3M, O(CH2CH2O)xH, O(CHCH3CH2O)xH, or O(CH2CH2O)aO(CHCH3CH2O)bH, x=1 to 30, y=1 to 30, a+b=1 to 30. The primary surfactant may be prepared in the acid form at one location and shipped as a neat product to be formulated into the final injection brine at or near the point of injection.

Dependencies are inferred from the claim text.