COMPOSITION FOR ENHANCED OIL RECOVERY AND METHOD OF ITS USE Russian patent published in 2023 - IPC C09K8/584 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: composition for enhanced oil recovery includes a non-ionic surfactant Neonol AF9-6 and anionic surfactants – petroleum sulfonates, a mixture of alpha-olefinsulfonates with the number of carbon atoms C14 and C16, a mixture of sulfonated monoalkylphenol and dialkylphenol in a mass ratio of 30:70 and sulfonated alkyltoluene with the following ratio of components, wt.%: Neonol AF9-6 45-60; said mixture of alpha-olefinsulfonates 7.5-15; petroleum sulfonates 7.5-13.5; said mixture of sulfonated monoalkyl and dialkylphenols 7.5-13.5; sulfonated alkyltoluene 7.5-13.5. In the method of using the composition for enhanced oil recovery, a slug of an aqueous solution of 0.46-1.84% concentration of the above composition for enhanced oil recovery with a volume of 0.3-0.5 volume of the open pore space is pumped, followed by an aqueous solution containing 0.05-0.15 wt.% polyacrylamide with a degree of hydrolysis from 10 to 30% and 2-7 wt.% diethanolamine, with a volume of 0.1 to 0.3 of the volume of the open pore space.

EFFECT: high increase in displacement efficiency after flooding.

5 cl, 3 dwg, 2 tbl, 12 ex