METHOD FOR ISOLATION OF WATER INFLUX IN WELL Russian patent published in 2016 - IPC E21B33/138 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry, in particular, to methods of limiting water influx in flooded reservoirs, installation of temporary barriers or bridges and alignment of injectivity profile of injection wells using water-soluble polymers. Method for isolation of water influx in well involves pumping to formation of first portion of gel forming composition with addition of sodium hypochlorite in following ratio, weight parts: water-soluble acrylamide polymer with molecular weight 5.9·10⁶ and degree of anionicity of 1.9 is 0.4-0.6, potassium chloride is 0.01-2.0, sodium thiosulfate is 0.1-0.6, sodium bichromate is 0.1-0.12, water with pH = 3.4-5.6 is 100, sodium hypochlorite solution is 6-20. Then second portion of gel forming composition without sodium hypochlorite is injected in following ratio, weight parts: water-soluble acrylamide polymer with molecular weight 5.9·10⁶ and degree of anionicity of 1.9 is 0.4-0.6 , potassium chloride is 0.01-2.0, sodium thiosulfate is 0.1-0.6, sodium bichromate is 0.1-0.12, water with pH = 3.4-5.6 is 100 composing 70-80 % of first portion volume, and well is held for 24 hours.

EFFECT: technical task of disclosure is high efficiency of application for limiting water influx in flooded reservoirs due to formation of cross-linked polymer system with simultaneous reduction of oil intake.

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