METHOD OF FRESH WATER SHUTOFF IN WELLS OF DEPOSITS OF HIGH-VISCOSITY OILS AND NATIVE BITUMENS Russian patent published in 2002 - IPC

FIELD: oil producing industry, particularly, water shutoff operations in producing wells in development of deposits of high-viscosity oils and native bitumens; applicable in equalization of injectivity profiles and backfilling of washed zones of injection wells. SUBSTANCE: method includes injection of reagent containing nonionic surfactant into zone of water shutoff with subsequent final forcing with water. Reagent is used in the form of hydrophobic emulsion prepared by mixing of nonionic surfactant in the form of APh_9-12,, and dehydrated native bitumen produced by intraformation burning, aqueous solution of sodium silicate with silicate module of 0.3-50.0 and cellulose ethers or polymers of acrylic series in amount of 0.05-0.1% of weight of hydrophobic emulsion. Water is used in the form of mineralized water with density of 1.16-1.18 g/cu.cm or 10-12-% hydrochloric acid. In this case, prior to injection of hydrophobic emulsion, said mineralized water or hydrochloric acid is injected. Cellulose ethers are used in the form of carboxymethyl cellulose or etoxymethyl cellulose. Polymers of acrylic series are used in the form of polyacrylamide. EFFECT: higher quality of water shutoff work, increased time between overhauls. 2 cl