METHOD OF SECONDARY OIL EXTRACTION Russian patent published in 2013 - IPC E21B43/22 C09K8/528 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises injection of 0.1-100000 ppm of amine alkyl phosphonic acid to the system of reservoir, said acid being selected from the group of compounds combined with amine neutraliser selected from special group of compounds provided that amine neutraliser represents the combination of at least two structurally different amine types. Note here that first one is hydrophobic type with hydrophilic-lipophilic balance smaller by at least two units than hydrophilic-lipophilic balance of the second one. Said first and second amine types are used in equivalent ratios (first one is more hydrophobic): second (more hydrophilic) n the range of 10:1 to 2:5.

EFFECT: higher efficiency of oil production, longer life of production structures.

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