ELIMINATION METHOD OF WELLS Russian patent published in 2019 - IPC E21B33/13 

FIELD: mining.

SUBSTANCE: invention relates to mining, namely, to elimination of wells for various purposes. Method includes installation of cement bridge, perforation of casing string, pumping of grouting mixture under pressure below pressure of hydraulic fracturing to create insulating screen. In elimination of oil and gas wells, as well as wells with radioactive, hazardous wastes, an insulating shield is built in the interval of occurrence of water bump by perforating the casing with a perforator, which provides creation of up to 1 cm in rocks in channels up to 2 cm in diameter. Subsequently, plastic hardening plugging mixture is pumped, which contains 70–75 wt% of bentonite clay powder at pressure equal to 0.8–0.9 of hydraulic fracturing pressure of the formation. During pumping of plastic hardening plugging mixture it is subjected to mechanical oscillations in range of 18–27 kHz.

EFFECT: improving reliability of elimination of wells of various purposes due to possibility of creation of strong water-proof screen both inside well and beyond its limits – in annular space and waterproof layer.

3 cl