OIL PRODUCTION METHOD Russian patent published in 2007 - IPC E21B43/22 

FIELD: oil production industry, particularly to develop oil fields and to increase reservoir recovery at medium or later stage of development.

SUBSTANCE: method involves injecting acid containing composition and composition containing surfactant and liquid hydrocarbon in reservoir, wherein the acid containing composition additionally has rock reaction inhibitor, namely Zeolite or synthetic zeolite powder or syenite alkali-aluminum concentrate or industrial lignosulphonates or carboxymethylcellulose or Polycell carboxymethylcellulose or alumochloride or aluminum hydrochloride. All the components are taken in the following amounts (% by weight): acid - 97.5-99.9, above inhibitor - 0.1-0.25. The acid containing composition is injected before or simultaneously with composition containing surfactant and liquid hydrocarbon comprising 5-16 % by weight of surfactant and 84-95% by weight of hydrocarbon. Ratio between composition containing surfactant and liquid hydrocarbon and acid containing composition is 2-4. Above components are simultaneously injected in producing and injection wells.

EFFECT: improved reservoir recovery due to increased oil-sweeping factor and factor of reservoir coverage with action as a result of water-saturated and oil-saturated reservoir zone permeability regulation.

2 cl, 3 ex, 8 tbl