DEVICE FOR CUTTING OUT PART OF CASING STRING Russian patent published in 2021 - IPC E21B29/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry and can be used in the construction and overhaul of wells. The device for cutting out a section of the casing string consists of a sliding hydraulic expander and a metal swarf collection unit. The expander consists of a cylindrical body with blind central and peripheral axial channels, which are hydraulically connected. The peripheral channels are concentric with respect to the central channel and are evenly spaced around the circumference. In the blind central channel, a piston and a pusher with cams are rigidly connected to each other. Through-length longitudinal grooves are made in the body, which are evenly and symmetrically spaced relative to the peripheral channels. Cutting blades equipped with cutters are suspended in longitudinal grooves on the axes. The cams are pivotally connected to the cutting blades by means of shackles. Between the longitudinal grooves in the wall of the housing, flushing channels are made, each of which is hydraulically connected to a peripheral channel located at the shortest distance from it. The piston has: the main and additional outer annular grooves, through radial channels and windows, an inner annular bore, and on the outer side surface of the piston - axial grooves, which are evenly spaced around the circumference between the main and additional outer annular grooves. The rod is coaxially attached to the piston, and an annular locking element is located outside the rod. The piston is spring-loaded against the body. The chip collection unit consists of several chip breakers and a guide head, which are interconnected by means of single articulated couplings. The lower end of the body is connected to the chip breaker by means of a double articulated coupling. The chip breaker is a bar on which brackets are fixed in several tiers along its length. Through channels are made in them, in which magnetic inserts are placed. Outside of the boom, with the help of brackets, curly ribs in the form of cylindrical spirals are installed concentrically, which have the same direction and pitch of winding.

EFFECT: increasing the productivity and safety of work related to cutting out a section of the casing, and reducing the likelihood of an emergency in the wellbore.

1 cl, 7 dwg