METHOD FOR GAS EXTRACTION FROM UNDERGROUND RESERVOIR Russian patent published in 2023 - IPC E21B43/22 C09K8/584 

FIELD: treatment of gas reservoirs.

SUBSTANCE: in a method for extracting gas from an underground gas reservoir, which includes displacing gas from zones of an underground gas reservoir characterized by low water and gas permeability, and extracting gas from an underground gas reservoir, to increase the degree of gas displacement, an aqueous solution of a non-ionic surfactant - ethoxylated alcohol of the general formula where n is a number from 82 to 87; R1 is a hydrocarbon group containing 12 to 14 carbon atoms, is pumped into the underground gas reservoir. The hydrophilic-lipophilic balance of said ethoxylated alcohol is greater than 18.8. At the same time, water in an aqueous solution has a total amount of dissolved salts up to 250,000 mg/l. The content of said ethoxylated alcohol in aqueous solution ranges from 0.01 to 40.00%.

EFFECT: increased degree of gas recovery from gas reservoirs, preferably carbonate gas reservoirs with low permeability, by improving rock wettability in water.

5 cl, 4 tbl, 31 ex