METHOD FOR IMPROVEMENT OF PERMEABILITY OF SALINE LOW-PERMEABILITY OIL FORMATION Russian patent published in 2015 - IPC E21B43/00 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: method involves dilution of salt rock with fresh or subsaline water by cyclic action on the formation, each of which includes pumping of a working agent to the saline oil formation through a well, closure of the well for the time of salt rock dilution, extraction of liquid from the formation through the same well. Cycles of action on the deposit are repeated till full coverage of the saline formation by action before opening of oil deposits contained in it and production of all the extracted oil deposits. Water pumping to the formation is performed at maximum possible constant bottom-hole pressure till reduction of the well water intake capacity by 2-8 times in comparison to its value at the pumping beginning, and extraction of liquid from the formation is performed at minimum possible constant bottom-hole pressure before the liquid with volume of at least 1.1-1.5 volumes of the fresh or subsaline water pumped to the formation earlier is removed to the surface.

EFFECT: increasing permeability of a saline formation throughout the area of its propagation, increasing productivity of production wells, increasing the coverage of the formation by action, volume of the removed oil deposits and acceleration of development rates.

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