METHOD FOR WATERPROOFING WORK IN THE WELL Russian patent published in 2022 - IPC E21B33/138 E21B43/22 C12R1/125 C09K8/582 

FIELD: oil industry.

SUBSTANCE: invention relates to microbiological methods for limiting water inflow in producing oil wells and can be used to carry out waterproofing work in a well in carbonate reservoirs of the Vereya and Bashkir deposits. The method for waterproofing works in a well includes injection into the formation of a solution containing bacteria of the Bacillus species and water. The water-producing interval of the reservoir and the water cut of the produced well production are determined in advance. A production well of the Bashkir, or Vereisky, or Verei-Bashkir horizon is selected with a water cut of 70% or more. Bacillus subtilis RNCIM B-2250D is used as the bacteria of the Bacillus species. The mass ratio of the cement mortar, 55% aqueous solution of calcium lactate and the activated solution of bacteria Bacillus subtilis RNCIM V-2250D is respectively 0.11-0.28 t : 0.18-0.25 t : 0.19-0.21 tons per 1 m of the water-producing interval of the formation. Pumping of a 55% aqueous solution of calcium lactate is carried out after pushing the cement mortar into the aquifer, and pumping of an activated solution of bacteria Bacillus subtilis RNCIM V-2250D after pushing a 55% aqueous solution of calcium lactate. Then, a technological exposure is carried out lasting from 10 to 20 hours, after which the production well is developed.

EFFECT: increasing the efficiency of water inflow isolation in a well with carbonate formations, increasing the life of the insulating screen, increasing the overhaul period of the well, expanding the technological capabilities of the method.

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