STRING SHOE Russian patent published in 2024 - IPC E21B7/20 E21B17/14 

FIELD: mining industry.

SUBSTANCE: string shoe includes hollow cylindrical housing with connecting thread in upper part for connection with casing string and recess in lower part of hollow cylindrical housing. String shoe has at least two cylindrical pins on the outer side of the lower part of the hollow cylindrical housing, as well as through longitudinal screw slots with possibility of alignment with cylindrical pins of hollow cylindrical housing. Lower part of the hollow cylindrical housing is equipped with a hollow tip with at least two side flushing holes evenly located along the perimeter and at least four teeth from hard-alloy material. At that, on the inner side of the hollow tip with teeth there is a recess with the possibility of installation of the working spring and interaction of one end of the working spring with the hollow tip. Recess in lower part of hollow cylindrical housing is made on inner side of housing with possibility of installation of working spring and interaction of other end of working spring with hollow cylindrical housing.

EFFECT: increasing the reliability of running and installing casing string in a wellbore with narrowing intervals and weak rock slough, as well as increasing operating efficiency.

1 cl, 3 dwg