SYSTEM FOR REPEATED ISOLATION OF ACCESS TO BOREHOLE Russian patent published in 2019 - IPC E21B34/14 E21B43/26 

FIELD: mining.

SUBSTANCE: group of inventions relates to mining and can be used in stimulating the formation. Disclosed is a sleeve for well toe with possibility of repeated closing, said sleeve has hole to allow access of fluid medium from inner volume of sleeve to be drilled into zone outside said sleeve. Bursting disc is installed inside the hole to prevent access of fluid medium from the internal volume of the coupling for the well toe to the zone outside the sleeve for the well toe. At the same time, when the fluid in the inner space of the sleeve reaches the preset level of the well, the rupture disc is removed or otherwise modified to provide access of the fluid medium through the hole. Sliding coupling is installed in sleeve for well toe so that sliding coupling can move to close hole, wherein preventing access of fluid medium from inner volume of sleeve for well toe into zone outside of sleeve for well toe, or sliding clutch can move for opening of hole, while providing access to fluid medium from inner volume of sleeve for well toe in zone outside of sleeve for well toe. Sliding coupling moves mechanically from the surface and is usually lowered into the well in the open position; at that, the hole is not closed by the sliding coupling.

EFFECT: technical result consists in providing the possibility of re-sealing access to the well.

25 cl, 6 dwg