SEALING DEVICE FOR CASING DRILLING Russian patent published in 2022 - IPC E21B33/02 E21B23/02 E21B31/18 E21B19/02 

FIELD: mining industry.

SUBSTANCE: invention relates to the mining industry and can be used when performing drilling operations, in particular for drilling wells on a casing string. The sealing device includes a hollow cylindrical body with a through top sub having an internal thread for connection with the top power drive of the drilling rig. The housing is equipped on the outside with at least three lugs symmetrically located on the surface of the housing. Spring-loaded claws are installed on the lugs, made with the possibility of holding the casing pipe by the edges of the coupling joint after the casing pipe coupling passes through the claws. Inside the housing in the lower part there is a radial ledge with a conical design in the lower part and a straight platform on top. The lower part of the upper sub from the inside is made in the form of a straight ledge, on which a thrust washer is installed, made with the possibility of creating a load on the casing string end through it. On the outer side of the lower part of the upper sub, an axial protrusion is made along the entire diameter. Between the upper sub and the body of the device, a rubber cuff is installed, made with a stop against the radial ledge, and with the possibility of pressing the casing pipe against the sleeve, as well as a characteristic depression from above, coinciding with the radial ledge.

EFFECT: improving the reliability of casing drilling.

1 cl, 2 dwg