Enhanced oil recovery method employing a high temperature brine tolerant foam-forming composition

A method of recovering hydrocarbons from a reservoir during gas injection into said reservoir comprising:

• (a) at least periodically injecting gas and a foam-forming composition into a reservoir wherein the reservoir temperature is not less than about 100.degree. F.;
• wherein the foam-forming composition comprises brine having not less than about 10% TDS, an effective foam-forming amount of a surfactant comprising a C.sub.10-16 AOS having a major amount of at least one of C.sub.10 AOS and C.sub.12 AOS, and an effective amount of at least one solubilizing component to increase the brine tolerance of the foam-forming composition, which solubilizing component is a mixture comprising ##STR4## where M is H, an alkali metal, alkaline earth metal, or ammonium, and R.sub.1 is a linear C.sub.6 -C.sub.16 alkyl group;
• and
• (b) contacting hydrocarbons in the reservoir with the foam and the gas so as to assist in the recovery of hydrocarbons from the reservoir.