Method and apparatus for removing a section of well tubing. The well tubing (24) is milled in an upward direction on a hydraulic tensioning device (14) which maintains a constant load on the section mill so that long sections of tubing can be removed in a near continuous procedure on a single trip into the well. The hydraulic device includes an indicator (30) to provide a signal as the device nears each end of a stroke to inform a user that: the section mill is about to bottom out and the work string needs to be raised to extend the device; and the device is fully extended and can begin another stroke. Embodiments are described for use in a rigless well abandonment procedure.

A tool for use in a borehole to perform a milling, under reaming, or other cutting operation includes a tool body configured for rotation about its longitudinal axis, within the borehole, and a set of cutters, the set including two or more cutters which, at least in a deployed configuration, extend outwardly from the tool body and are fixedly coupled together whilst being pivotally coupled to the tool body substantially on said axis so that the cutters rotate with the tool body whilst being pivotable together relative to the tool body during cutting.

A rotary cutting tool, which may be a reamer for enlarging an underground borehole or a mill to remove tubing by cutting into the inside wall of the tubing, has a plurality of cutter assemblies distributed azimuthally around a longitudinal axis of the tool, wherein each cutter assembly includes a supporting structure bearing a sequence of cutters which extends axially along the tool with leading surfaces facing in a direction of rotation of the tool. The cutters of each sequence are positioned at a plurality of circumferential positions such that no more than three cutters of the sequence are aligned on any line parallel to the longitudinal axis of the tool. In an overlapping arrangement, a plurality of cutters in the sequence may have a leading face circumferentially behind the leading face but ahead of the trailing end of at least one other cutter.

A retractable and extendable roller reamer is positioned on a string. The retractable and extendable roller reamer is configured to support and centralize the string within the wellbore. An extension and retraction mechanism is configured to extend and retract the roller reamer. A hydraulic power unit is configured to control the extension and retraction mechanism. Sensors positioned on or within the roller reamer. The sensors are configured to detect parameters of the well-string stabilizing system. A controller is operatively coupled to the hydraulic power unit and the plurality of sensors. The controller is configured to be positioned in a wellbore. The controller is configured to receive signals from the sensors. The signals represent the parameters detected by the sensors. The controller is configured to identify the parameters represented by the signals. The controller is configured to adjust a well-string stabilizing operation in response to the received signals.

A retractable and extendable cone-type reamer is positioned on a drill string. An extension and retraction mechanism is configured to extend and retract the cone-type reamer. A hydraulic power unit is configured to control the extension and retraction mechanism. Sensors are positioned on or within the cone-type reamer. The sensors are configured to detect parameters of the wellbore-type hole opening system. A controller is operatively coupled to the hydraulic power unit and the sensors. The controller is configured to be positioned in a wellbore. The controller is configured to receive signals from the sensors. The signals represent the parameters detected by the sensors. The controller is configured to identify the parameters represented by the signals. The controller is configured to adjust a parameter of a wellbore-type hole opening operation in response to the received signals.

Various implementations described herein refer to a downhole device having a body with a cavity. The downhole device includes a mechanical element disposed within the cavity. The mechanical element has a base with a left-extending member and a right-extending member that holds the mechanical element in position within an interior space of the cavity. The downhole device includes an inflatable bladder disposed within the cavity between an interior sidewall of the cavity and the base of the mechanical element. The inflatable bladder has an opening on one end for receiving hydraulic fluid, and the inflatable bladder is activated and deactivated to selectively displace the mechanical element in and out of the cavity.

A perforating tool usable in a well casing to perforate the well casing is described. Perforating tool includes an activation member disposed in body wherein the activation member is moveable relative to the body to move at least one working member between and inwardly retracted condition an outwardly deployed condition relative to the body. A plurality of pistons is arranged to move the activation member relative to the body, each piston being disposed in a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body.

An earth-boring tool includes a movable component and an additive manufacturing formed flow control device in fluid communication with the movable component and configured to control a flowrate of the hydraulic fluid through the additive manufacturing formed flow control device, wherein the additive manufacturing formed flow control device is configured to control a movement of the movable component via the flowrate of hydraulic fluid through the additive manufacturing formed flow control device. An earth-boring tool includes an additive manufacturing formed flow control device in fluid communication with one or more components of the earth-boring tool and configured to provide a cooling fluid to the one or more components of the earth-boring tool.

A reaming tool for enlarging an underground borehole comprises a plurality of cutter assemblies distributed azimuthally around a longitudinal axis of the tool, wherein each cutter assembly includes a supporting structure bearing a sequence of cutters which have hard surfaces exposed and facing in a direction of rotation of the tool. The outer surface of the support structure on each cutter assembly includes zones which each face towards an end of the assembly and is configured such that as it extends circumferentially relative to the tool axis in the direction opposite to rotation of the tool, it also extends away from an end of the assembly.

Reamer for earth-boring applications may include a body having a longitudinal axis and a blade carried by the body. The blade may include at least one cutting element located at a first radial distance from the longitudinal axis and a gage pad located at a second, smaller radial distance from the longitudinal axis. Methods of enlarging pilot holes in earth formations utilizing reamers may involve removing earth material from a sidewall of the pilot hole utilizing at least one cutting element located at a first radial distance from a longitudinal axis of a body of the reamer on a blade of a reamer. The reamer may be stabilized by placing a gage pad located on the blade in sliding contact with a portion of the sidewall of the pilot hole, the gage pad located at a second, smaller radial distance from the longitudinal axis.