METHOD OF ISOLATION OF WATER-ENCROACHED OIL RESERVOIRS Russian patent published in 2001 - IPC

FIELD: oil producing industry. SUBSTANCE: method is used for increasing coverage of formation by treatment in injection of oil displacing agents through injection wells and reduction of water-cutting of products in oil recovery from producing wells. The method includes injection of isolating composition based on hydrocarbons into formation. Isolating composition is used in the form of mixture of oil, polymer of acids of acrylic series and glycol with the following ratio of components, wt.%: polymer of acrylic acid series, 1.7-40.0; glycol, 3.0-20.0; oil, the balance. Glycol is used in the form of byproduct of production of individual glycols including, wt.%: monoethylene glycol, 4.0-6.0; diethylene glycol, 32.0-38.0; triethylene glycol, 17.0-23.0; tetraethylene glycol, 30.0-34.0; pentaethylene glycol, 5.0-11.0. EFFECT: increased blocking effect of water-encroached pores of formation, higher degree of coverage of hydrophilic reservoirs by selective treatment. 2 cl, 2 tbl