WELL KILLING METHOD Russian patent published in 2015 - IPC E21B43/12 

FIELD: oil and gas industry.

SUBSTANCE: as per the proposed method, pumping of design volume of a gas-liquid mixture with nitrogen as a phase is performed to the bottom-hole zone. The gas-liquid mixture is forced through with a liquid compensating a formation pressure. Liquid replacement is performed in the well volume with the liquid compensating the formation pressure. Non-Newtonian marketable oil is used for the gas-liquid mixture. Gasification of marketable oil with nitrogen is performed in the ratio of 100-125 l of nitrogen per 1 l of marketable oil. As a liquid compensating the formation pressure, a liquid on a hydrocarbon base is used. A water bath is installed at a perforation interval after technological exposure of gas-cut marketable oil in the bottom-hole zone before redistribution of nitrogen in porous medium of the formation. Therefore, an additional boundary line is created between the gas-cut marketable oil and liquid on the hydrocarbon base.

EFFECT: improving well killing efficiency owing to providing reliable and continuous insulation of influx of formation fluid to the well shaft for the period of well repair operations.

3 cl, 2 ex