Abstract: A steam foam method of recovering hydrocarbons from an underground hydrocarbon formation, which comprises injecting steam through an injection well into the formation, injecting an aqueous solution having a salinity greater than about 1% by weight and a pH of about 8 to about 12, comprising about 0.1% to about 5% by weight of a fatty acid salt having about 10 to about 24 carbon atoms, and injecting steam into the formation to sweep hydrocarbons towards the production well for recovery.

Abstract: The invention is a method for increasing the effectiveness of steam or carbon dioxide foaming operations for improving conformance during steam or carbon dioxide floods by adding to the surfactant foaming solution an alcohol having about 8 to about 20 carbon atoms in a concentration such that the ratio of alcohol to surfactant in the foaming solution is between about 1:6 and about 1:2.

Abstract: The invention is a method for increasing the effectiveness of steam or carbon dioxide foaming operations for improving conformance during steam or carbon dioxide floods by adding to the surfactant foaming solution a fatty acid having about 12 to about 20 carbon atoms in a concentration such that the ratio of fatty acid to surfactant in the foaming solution is between about 1:4 and about 3:2.

Abstract: A method for producing a homogeneous oil-in-water microemulsion by first creating a surfactant, oil and water mixture, adding salt to the mixture in a sufficient quantity to drive the mixture into a Type III or Type II(+) phase regime, preparing a solution having a selected salinity lower than the salinity of the Type III or Type II(+) phase regime, and mixing a sufficient amount of the lower salinity solution with the Type III or Type II(+) regime to invert the Type III or Type II(+) regime into a Type II(-) oil-in-water microemulsion. The microemulsion may be used in a surfactant flood to recover hydrocarbons from underground formations.

Abstract: The invention is a method of producing a homogeneous oil-in-water microemulsion comprised of oil, brine and surfactant, wherein the oil has a equivalent alkane carbon number higher than the crude oil which is to be recovered by the microemulsion. A mixture of oil, water and surfactant is prepared in the same relative ratios to oil and surfactant as in the microemulsion desired to be injected, but at higher concentration relative to water and salt than in the microemulsion to be injected. The cloudy mixture is stirred while adding salt until the mixture changes to a clear oil-in-water microemulsion concentrate. The microemulsion concentrate is then mixed with sufficient water of the proper salinity to form the oil-in-water microemulsion desired to be injected.