Abstract: The invention relates to a process for mineral oil production, in which an aqueous saline surfactant formulation comprising a surfactant mixture of at least one anionic surfactant of the general formula R1—O—(CH2C(CH3)HO)x—(CH2CH2O)y—SO3M and at least one anionic surfactant of the general formula R2—O—(CH2CH2O)z—SO3M and a base is injected through injection boreholes into a mineral oil deposit, and crude oil is withdrawn from the deposit through production boreholes. The invention further relates to the surfactant mixture, a concentrate comprising the surfactant mixture and a manufacturing process as well as the use of the surfactant mixture and the con- centrate in the production of mineral oil from underground mineral oil deposits.

Abstract: The invention relates to a process for mineral oil production, in which an aqueous saline surfactant formulation comprising a surfactant mixture of at least one anionic surfactant of the general formula R1—O—(CH2C(CH3)HO)x, —(CH2CH2O)y—SO3M and at least one amionic surfactant of the general formula R2—O—(CH2CH2O)2—SO3M and a base is injected through injection boreholes into a mineral oil deposit, and crude oil is withdrawn from the deposit through production boreholes. The invention further relates to the surfactant mixture, a concentrate comprising the surfactant mixture and a manufacturing process as well as the use of the surfactant mixture and the con- centrate in the production of mineral oil from underground mineral oil deposits.

Abstract: A binary or ternary surfactant mixture for use in enhanced oil recovery within a reservoir having total dissolved solids greater than approximately 80,000 parts per million (i.e., heavy to extreme brine conditions) includes at least two of a propoxylated/ethoxylated alcohol sulfate, an ethoxylated alcohol sulfate, and a monoalkyl or dialkyl diphenyloxide disulfonate. The surfactant mixture is used without alcohol, which is unnecessary to maintain solution stability and good coalescence rates and thus improves compatibility with polymers added to improve the mobility ratio. During testing, exceptional solution stability, excellent oil recovery capability, and good compatibility was observed with these surfactant blends. The mixtures are effective at concentrations below 1% and as low as 0.1% by weight.