FOAMING COMPOSITION WITH COMBINED USE OF SURFACTANTS FOR INCREASING OIL RECOVERY Russian patent published in 2019 - IPC C09K8/584 C09K8/594 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a foaming composition and a method of using said composition in a method of increasing oil recovery from an oil-bearing formation. Foaming composition for use in the method of increasing oil recovery contains a non-ionic surfactant and an anionic surfactant, wherein the non-ionic surfactant is one or more alcohol alkoxylates of formula RO-(CR¹R²R³R⁴O)_x(C₂H₄O)_y-H, where R is selected from a group consisting of linear alkyl, branched alkyl, cyclic alkyl and alkaryl groups containing from 1 to 30 carbon atoms; R¹, R², R³ and R⁴ are independently selected from a group consisting of H, a branched alkyl, linear alkyl, cyclic alkyl or alkaryl groups containing 1 to 6 carbon atoms, provided that one or more of the following conditions are met: R¹, R², R³ and R⁴ all simultaneously can not represent H, sum of carbon atoms in R¹+ R²+ R³+ R⁴ less than or equal to about 8; x is from 1 to 20, inclusive, wherein sum of carbon atoms in R¹+ R²+ R³+ R⁴ is equal to 1, or x is integer from 1 to 2 inclusive, wherein sum of carbon atoms in R¹+ R²+ R³+ R⁴ ranges from 2 to 8; and is integer from 0 to 99, and said anionic surfactant is one or more compounds of (di)sulphonate of alkyldiphenyl oxide of formula

,

where R⁵ is C₃-C₂₀ an alkyl radical; X is H, an alkali metal, an alkali-earth metal or ammonium.

EFFECT: technical result is creation of foam-forming composition with reduced adsorption tendency in strata of rocks, improved resistance to salt solution and high temperature, improved stability in presence of crude oil, as well as possibility of its transportation together with CO₂.

11 cl, 2 dwg, 3 tbl, 1 ex