METHOD FOR WELL BOTTOM ZONE TREATMENT Russian patent published in 2006 - IPC E21B43/22 

FIELD: oil production industry, particularly to stimulate oil production and increase well intake capacity.

SUBSTANCE: well bottom treatment method involves successively injecting technological solution of acid, neutral or alkaline nature in reservoir to provide reaction between the solutions and natural or industrial mudding agents in perforated well environment zone. Prior to technological solution injection oil-carrying layers having non-uniform permeability are blocked by successive injection of invert hydrocarbon emulsion, water-shutoff material and mutual organic solvent under predetermined pressure and with predetermined flow-rate. Then technological solvents are injected under predetermined pressure and with predetermined flow-rate. Alkali hydrosulfate is added to acid solution. Mutual organic solvent is used as neutral medium. Alkaline solution if forced into reservoir by predetermined hydrocarbon solvent volume. After that technological time-delay is exercised, reaction products are removed and fluid inflow from reservoir is stimulated up to fluid of constant composition appearance.

EFFECT: increased oil output and oil production stimulation due to treatment of bottom zone in non-uniform reservoir contaminated with complex mudding agents and due to applying selective action upon mudded layer having low-permeability along with temporarily isolating flooded layers having high permeability.

25 cl, 2 ex, 1 tbl, 1 dwg