FOAM-FORMING SURFACTANT COMPOSITIONS

This invention relates to a foam-forming surfactant composition comprising at least two surfactants whereof at least one is a sulfosuccinamate, and at least one is a sulfosuccinate, and optionally, a solvent, and to a method of recovering oil or gas comprising the steps of generating a foam, feeding the foam into a subterranean oil- or gas-bearing geological formation, and collecting mineral oil or natural gas driven by the foam in a production well, wherein the foam is generated by intimate mixing of the foam-forming surfactant composition with a gas in a foam generator, or by introduction of at least one of water and gases, together or intermittently or in alternating sequence, slugs of a gas which may be in a supercritical or non-supercritical state, and of water, wherein the foam-forming surfactant composition can be admixed to the water or to the gas if the gas is in a supercritical state or be introduced separately as solution into the formation.