Downhole cutting tool positioning assemblies and methods to cut a tubular are presented. The assembly includes a drive screw, a drive nut coupled to the drive screw and configured to shift from a first position to a second position as the drive screw rotates in a first drive screw direction, a pressure piston configured to shift from a first position to a second position in response to force applied to the pressure piston, a chamber having a pressure fluid that is pressurized by the pressure piston as the pressure piston shifts from the first position towards the second position, a sleeve configured to slide from a first position towards a second position in response to pressure from the pressure fluid, and a latch key having a profile configured to shift radially to engage a tubular groove as the sleeve shifts from the first position towards the second position.

A mechanical service tool that may include one or more anchors, a cutter, a communication and control system, and one or more sensors, as well as methods for operating the mechanical service tool, are provided. The one or more anchors may extend radially from the mechanical service tool and the cutter may move relative to the mechanical service tool. The cutter may include a drilling bit. The communication and control system may obtain remote commands that control the cutter, the one or more anchors, or both. The one or more sensors may detect operational conditions of the mechanical service tool and may be operatively coupled to the communication and control system.

The invention relates to a radial driller for drilling a hole in a well tubular, the radial driller comprising a rotating sleeve that is rotated by means an axial drive organ via an angular gear, the rotating sleeve housing a partially closed cylinder, the cylinder housing a hydraulic piston, a first hydraulic chamber situated below the hydraulic piston, and a second hydraulic chamber situated above the hydraulic piston, the hydraulic piston having a connecting rod arrangement extending above the piston and through an opening in a dividing wall dividing the cylinder from a multipurpose section, and a drill bit connected to the hydraulic piston via the connecting rod arrangement. According to the invention, the radial driller further comprises a multipurpose element positioned directly below the drill bit, the multipurpose element defining a retracting chamber between the multipurpose element and the dividing wall.

The invention relates to a radial driller for drilling a hole in a well tubular, the radial driller comprising a rotating sleeve that is rotated by means an axial drive organ via an angular gear, the rotating sleeve housing a partially closed cylinder, the cylinder housing a hydraulic piston, a first hydraulic chamber situated below the hydraulic piston, and a second hydraulic chamber situated above the hydraulic piston, the hydraulic piston having a connecting rod arrangement extending above the piston and through an opening in a dividing wall dividing the cylinder from a multipurpose section, and a drill bit connected to the hydraulic piston via the connecting rod arrangement. According to the invention, the radial driller further comprises a multipurpose element positioned directly below the drill bit, the multipurpose element defining a retracting chamber between the multipurpose element and the dividing wall.

A sidetracking method includes lowering a sidetrack assembly to a target zone of a wellbore comprising a casing. The sidetrack assembly comprising a cutting tool coupled to a wellbore string and a whipstock releasably coupled to the cutting tool. The method includes setting the whipstock on a wall of the wellbore, pulling the wellbore string, decoupling the cutting tool from the whipstock, actuating the cutter, cutting along a cut profile of the casing to cut free a portion of the casing at the target zone, actuating the mechanical fasteners, fastening the portion of the casing to the cutting tool, pulling the wellbore string, detaching the portion of the casing from the wall of the wellbore, drilling, with a directional drill string a sidetrack wellbore extending from the window to a downhole location of the sidetrack wellbore, and removing the whipstock from the wellbore.

A sidetracking method includes lowering a sidetrack assembly to a target zone of a wellbore comprising a casing. The sidetrack assembly comprising a cutting tool coupled to a wellbore string and a whipstock releasably coupled to the cutting tool. The method includes setting the whipstock on a wall of the wellbore, pulling the wellbore string, decoupling the cutting tool from the whipstock, actuating the cutter, cutting along a cut profile of the casing to cut free a portion of the casing at the target zone, actuating the mechanical fasteners, fastening the portion of the casing to the cutting tool, pulling the wellbore string, detaching the portion of the casing from the wall of the wellbore, drilling, with a directional drill string a sidetrack wellbore extending from the window to a downhole location of the sidetrack wellbore, and removing the whipstock from the wellbore.

A deflection mechanism may include a first incline and a second incline for interacting with legs of a junction assembly to selectively deflect each of the legs in a desired direction in a multilateral wellbore system. The deflection mechanism may include a window assembly for a main borehole of the wellbore and having a selective-deflection profile positioned proximate to an entrance into a lateral borehole extending from the main borehole. One leg of the junction assembly may include a surface profiled corresponding to an angle of the first incline to deflect the leg toward the lateral borehole. Another leg of the junction assembly may include a surface profiled corresponding to an angle of the second incline to deflect the leg toward a whipstock assembly positioned internal to the window assembly.

A deflection mechanism may include a first incline and a second incline for interacting with legs of a junction assembly to selectively deflect each of the legs in a desired direction in a multilateral wellbore system. The deflection mechanism may include a window assembly for a main borehole of the wellbore and having a selective-deflection profile positioned proximate to an entrance into a lateral borehole extending from the main borehole. One leg of the junction assembly may include a surface profiled corresponding to an angle of the first incline to deflect the leg toward the lateral borehole. Another leg of the junction assembly may include a surface profiled corresponding to an angle of the second incline to deflect the leg toward a whipstock assembly positioned internal to the window assembly.

A method for lateral drilling into a subterranean formation whereby a shoe is positioned in a well casing, the shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod and casing mill assembly are inserted into the well casing and through the passageway in the shoe until a casing mill end of the casing mill assembly substantially abuts the well casing. The rod and casing mill assembly are rotated until the casing mill end substantially forms a perforation in the well casing. An internally rotating nozzle is attached to an end of a hose and is pushed through the passageway and the perforation into the subterranean formation, and fluid is ejected from tangential jets into the subterranean formation for impinging upon and eroding the subterranean formation.

A method for lateral drilling into a subterranean formation whereby a shoe is positioned in a well casing, the shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod and casing mill assembly are inserted into the well casing and through the passageway in the shoe until a casing mill end of the casing mill assembly substantially abuts the well casing. The rod and casing mill assembly are rotated until the casing mill end substantially forms a perforation in the well casing. An internally rotating nozzle is attached to an end of a hose and is pushed through the passageway and the perforation into the subterranean formation, and fluid is ejected from tangential jets into the subterranean formation for impinging upon and eroding the subterranean formation.