DEVICE FOR TORN PIPE REMOVAL FROM WELL Russian patent published in 2007 - IPC E21B31/20 

FIELD: oil production, particularly to fish inner pipe surfaces and remove torn pipes from wells.

SUBSTANCE: device comprises tap with through axial orifice and conical tip provided with fishing thread, and clutch head with connection thread adapted to be connected with drill string, as well as hollow cylindrical body and sub arranged in upper body part to connect the body with the tap and clutch head by means of threaded connections. Lower part of hollow body is provided with through orifices arranged in several rows in planes transversal to device axis. Collet means is located inside hollow cylindrical body over the orifices. The collet means is supported by centering ring fixedly secured with retaining screws arranged in through orifices of one row. Collet means leafs are located below the tap and spaced a distance defined as S₁=L_c-S₂ therefrom, where S₂ is length of tap fishing thread screwing in clutch body, mm, L_c is length of clutch made in pipe to be fished, mm.

EFFECT: increased reliability of pipe engagement and retention and decreased assemblage and maintenance costs.

3 dwg