PIPE SPEAR Russian patent published in 2021 - IPC E21B31/18 

FIELD: pipe string broken part extraction.

SUBSTANCE: inventions group relates to an external spear for capturing and retrieving a broken part of a pipe string from a well. The device contains housing with an annular protrusion made in it, a collet located below the annular protrusion, a housing cover with an opening, a piston assembly. The piston assembly includes a piston and a first rod and a second rod mounted on it. The piston assembly includes a piston and a first rod and a second rod mounted on it. The piston is located between the cover and the annular ledge. The first hydraulic channel is located above the piston, and the second hydraulic channel is located below the piston. The inner surface of the lower part of the body is made in the form of an expanding cone. The first rod is movable in the opening of the housing cover. The second rod is movable in the annular ledge and is connected to the collet. To move the tubular element, the collet is brought to the tubular element, fluid is supplied to the second hydraulic channel to move the body relative to the collet and clamp the tubular element by the working surface of the collet, the tubular element is moved to the required position and fluid is supplied to the first hydraulic channel to move the body relative to the collet and expand the tubular element with the working surface of the collet.

EFFECT: reliability of clamping and unclamping the tubular element are increased while simplifying the design of the spear and reducing the specific contact stresses exerted by the collet on the tubular element.

10 cl, 5 dwg