METHOD FOR EXTRACTION OF FALLEN PIPES FROM WELL, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2013 - IPC E21B31/00 

FIELD: oil and gas industry.

SUBSTANCE: mechanical connection of a pipe to a lifting system is performed by introduction of electrodes-projections to holes formed in advance in the wall of the extreme extracted pipe by means of an electrochemical dilution method. Electrodes-projections are connected to the lifting system. The device includes a housing of a round elongated shape. Perpendicular to longitudinal axis of the housing there made are two rectangular slots in cross section, which are parallel to each other and which do not pass through its axis. Dielectric inserts are inserted into slots; a rectangular electrode having an inclined slope on one end is placed in each insert. The other end of electrode represents a flat platform located at a right angle to the electrode length. Each electrode is connected to a wire that attaches it to a negative terminal of the direct current source on day source. An electrolyte chamber is located in upper part of the housing. A submersible pump supplying the electrolyte to the zone of anodic dissolution of metal of lifted pipe is arranged inside the chamber. On electrodes there are two platforms on outer end surface. On one of them there fixed is a dielectric platform providing a gap between a negative electrode and a positive electrode - lifted pipe.

EFFECT: improving pipe extraction reliability and efficiency.

2 cl, 3 dwg