FIELD: technological processes.
SUBSTANCE: invention relates to methods of increasing extraction of crude oil from an underground hydrocarbon-bearing formation. Composition for increasing extraction of crude oil from underground hydrocarbon-containing formation, where composition contains: ether of sulphonate and alcohol, having given formula, and a quaternary ammonium salt of the given formula, where the weight ratio of ether of the sulphonate and alcohol to the quaternary ammonium salt ranges from about 40:1 to about 1:1. Method for increasing extraction of crude oil from an underground hydrocarbon-containing formation, comprising injecting said composition into a well, which is in contact with the underground hydrocarbon-containing formation, in an amount effective in reducing inter-phase tension between fluid for hydraulic fracturing of the formation and oil trapped within the formation, and in change of wettability of underground hydrocarbon-containing formation, for extraction of crude oil from underground hydrocarbon-containing formation. Invention is developed in dependent items of the formula.
EFFECT: higher efficiency of treatment.
18 cl, 5 ex, 4 tbl, 1 dwg
