METHOD FOR LIMITING WATER INFLUX IN WELL Russian patent published in 2015 - IPC E21B33/13 C09K8/508 

FIELD: oil and gas industry.

SUBSTANCE: method for limiting water influx in well includes injection of water-soluble polymer and salts to the reservoir. Gel-forming compound is prepared preliminary by successive solving of components in 100 weight fractions of fresh water at temperature of 18-25°C in the following order: 0.01-2.0 weight fractions of potassium chloride, 0.1-0.6 weight fractions of sodium thiosulfate, 0.4-0.6 weight fractions of water-soluble acrylamide polymer with molecular weight of 5.9·10⁶ and degree of anionicity of 1.9, 0.1-0.12 weight fractions of sodium bichromate. Gel-forming compound is injected to water-bearing reservoir within 2-5 cycles with volume of 5-20 m³ each and consumption rate of 100-200 l/min. At that fresh water for each cycle is brought to pH=3.4-5.6 by adding 5-15 l of inhibited hydrochloric acid. Then gel-forming compound is injected into the well with cross-binding of the first cycle but not before completed injection of gel-forming compound during the last cycle.

EFFECT: improved efficiency of water inflow limitation in water-flooded reservoirs and increased duration of the effect upon repair.

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