Abstract: The invention relates to a composition C which comprises, in an aqueous medium M: surfactants suitable for creating a foam in the presence of a gas; and polymers P based on acrylamide or acrylamido units, having a molecular mass of 1,000,000 to 20,000,000 g/mol; or: composition C has a viscosity of less than 6 mPa·s; and the content of polymer P is greater than the concentration limit beyond which the apparent viscosity of a foam obtained from composition C is greater by at least 10% than the apparent viscosity of a foam obtained from the same composition but deprived of polymers. The invention further relates to the use of these compositions as foaming compositions for EOR.

Abstract: The invention relates to a composition which comprises within an aqueous medium: —at least one ethoxylated alkylamine; and—at least one amphoteric or zwitterionic surfactant. The invention further relates to the use of said compositions as foaming compositions, in particular for EOR (enhanced oil recovery).

Abstract: The invention relates to a composition C which comprises, in an aqueous medium M: surfactants suitable for creating a foam in the presence of a gas; and polymers P based on acrylamide or acrylamido units, having a molecular mass of 1,000,000 to 20,000,000 g/mol; or: composition C has a viscosity of less than 6 mPa·s; and the content of polymer P is greater than the concentration limit beyond which the apparent viscosity of a foam obtained from composition C is greater by at least 10% than the apparent viscosity of a foam obtained from the same composition but deprived of polymers. The invention further relates to the use of these compositions as foaming compositions for EOR.

Abstract: A method for extracting a crude oil contained in a geological formation comprises a step of fracturing the geological formation, by injection of a specific aqueous extraction fluid under pressure, which contains at least one surfactant that reduces the interfacial tension between the extraction fluid and the crude oil to be extracted to below 0.1 mN/m; followed by a discharge step (“flowback”). Additionally, the original fracturing fluids used in this method, and the additives used in these fracturing fluids include a surfactant or a surfactant mixture which make it possible to reduce the interfacial tension between the fluid and a petroleum oil below 0.1 mN/m.

Abstract: The invention relates to a method for extracting a crude oil contained in a geological formation, which comprises a step of fracturing said geological formation, by injection of a specific aqueous extraction fluid under pressure, which contains at least one surfactant that reduces the interfacial tension between the extraction fluid and the crude oil to be extracted to below 0.1 mN/m; followed by a discharge step (“flowback”). The invention likewise relates to the original fracturing fluids used in this method, and the additives used in these fracturing fluids.