METHOD OF SHUTOFF OF WATER INFLOW INTO WELL Russian patent published in 2000 - IPC

FIELD: oil producing industry, particularly, water shutoff operations in producing wells, applicable in equalization of injectivity profiles and plugging of flushed zones of injection wells. SUBSTANCE: method includes preliminary cleaning of bottom-hole zone with emulsion of hydrochloric and hydrofluoric acids in hydrocarbon fluid, for instance, light resin of pyrolysis or bottoms of benzene rectification. Water shutoff compound is used in form of mixture of aqueous solutions of sodium silicate and hydrochloric acid with addition of wood flour in amount of 0.1-2.0%. Wood flour is preliminarily treated with alkali solution, for instance, solution of sodium hydroxide, sodium silicate, sodium carbonate, or solutions of their mixtures with concentration of 1-3% and weight ratio of 1:(0.1-0.3). EFFECT: higher quality of shutoff operations due to preliminary treatment of bottom-hole zones.