HYDRO-MECHANICAL CATCHER Russian patent published in 2007 - IPC E21B31/113 

FIELD: drilling equipment, namely engineering of devices for freeing wedged part of drilling column in wells.

SUBSTANCE: device includes tubular body and hollow mandrel which are telescopically interconnected. The body is composed of parts, and contains first packer and grooves on internal surface on the side of first edge. In the middle section the body contains internal anvil-shelves, and on the side of second edge - an internal thread. The mandrel is composed of parts, contains threaded tail and grooves on external surface on the side of first edge of body, strikers between internal anvil-shelves of body, at least one piston with second packer on the side of second edge of body. Strikers and piston form a chamber filled with working liquid. The device contains at least one limiting mechanism for connecting working liquid to chamber for liquid in form of belt of greater diameter of mandrel and circular valve, installed in working liquid chamber with mandrel passing through internal hollow. The internal surface of circular valve is in contact with belt of greater diameter of mandrel. Longitudinal drive of circular valve is limited between two stops, projecting from internal surface of the body. Longitudinal drive equals at least the longitudinal drive of mandrel relatively to spring-loaded mechanism of latch from the start of application of force which makes the mandrel enter the body before setting of latch mechanism to working position. Between first and second packers at least two packers are positioned, which divide the chamber for liquid on three sections. Spring-loaded mechanism of latch is contained inside the working liquid chamber, blocking longitudinal drive of mandrel relatively to the body. The stop which limits longitudinal drive of circular valve towards the second edge of body with internal thread, is formed by shelf from lesser diameter of internal surface of body, to which one of packers, which divide working liquid chamber onto sections, is movably connected. Piston with packer on the side of second edge of body with internal thread is made with possible sliding relatively to mandrel and provided with its own packer in contact with mandrel.

EFFECT: increased reliability and resource, prevented unwanted activation, destruction or wedging of drill bit.

4 cl, 4 dwg