The disclosure provides a drill bit including a bit body and a blade extending form the bit body. The blade includes a first element protruding from a surface of the blade and a second element protruding from the surface of the blade. The first element and the second element are each configured to extend or retract relative to the surface of the blade and are coupled to each other such that when the second element retracts relative to the surface of the blade, the first element extends relative to the surface of the blade. The first element is disposed within a first pocket formed in the surface of the blade, and the second element is disposed within a second pocket formed in the surface of the blade. A communication channel is formed between the first pocket and the second pocket.

A reamer includes a housing, a flow tube extending along a longitudinal axis of the housing, and a plurality of reamer blocks arranged radially around the flow tube and configured to extend and retract relative to the housing. The reamer has a reamer ratio between 1.8 and 2.5. The reamer ratio is a ratio between an expanded diameter of the reamer when the plurality of reamer blocks is extended and a retracted diameter of the reamer when the plurality of reamer blocks is retracted.

A section mill including a housing, a cutter pivotally connected to the housing, a drive piston operably connected to the cutter to radially expand or retract the cutter depending upon longitudinal position of the drive piston relative to the housing, and a limit configuration in operable contact with the drive piston to limit drive piston stroke responsive to hydraulic pressure on the drive piston. A method for cutting casing including determining condition of a structure radially outward of a casing to be cut, selecting an amount of expansion of a cutter based upon the determining, and cutting the casing. A borehole system including a borehole in a subsurface formation, a string in the borehole, and a section mill as in any prior embodiment disposed in the borehole.

A wellbore reamer assembly positionable on a drill string in a wellbore includes a reamer body having an internal cavity and multiple radial openings, multiple cutting structures each positioned in one of the radial openings in the reamer body, and a fluid-activated expandable support element positioned in the internal cavity of the reamer body adjacent the cutting structures. The cutting structures are extendable radially away from a central longitudinal axis of the reamer body through respective radial openings and retractable toward the central longitudinal axis of the reamer body.

A vibration assembly of a drilling tool for drilling a wellbore penetrating a subterranean formation is disclosed. The downhole drilling tool includes a drill string, a bottomhole assembly and a drill bit. The vibration assembly includes a housing (334a) operatively connectable to the bottomhole assembly, expanders (122) positionable in the housing and radially extendable and retractable thereabout, and a radial vibrator (comprising mandrel (446), enlarger spring (48), cam portion (458) and vibration spring (570) operatively connectable to the expanders to vibrationally move the expanders against the wall of the wellbore whereby movement of the downhole tool is altered during drilling.

This cutting assembly provides a radially grooved body insert upon which cutter arms with complementary radial grooves may translate to extend the cutter arms in a radial fashion from a body of a downhole drilling assembly. This improved cutting assembly design can be incorporated into an underreamer, hole opener, drill bit, or section mill.

The invention discloses an anchor rod multi-section reaming machine tool and an application thereof. The machine tool is used cooperatively with an anchor rod drill rig (M), wherein a hydraulic cylinder (41) is connected with a hydraulic station (1) through a pipe, and the hydraulic cylinder (41) is fixed at a lower end of a drill rod (M1) of the anchor rod drill rig (M) and connected with the hydraulic station (1). A piston (412) is arranged inside a cylinder body (411) of the hydraulic cylinder (41) and axially moves relative to the cylinder body (411) such that the cylinder body (411) is divided into a hydraulic cylinder upper chamber (4111) and a hydraulic cylinder lower chamber (4112) which have variable volume. An upper end of a piston rod (413) is fixed at a lower portion of the piston (412) and a lower end of the piston rod (413) is fixed at an upper portion of an arch pressing device fixing disc (42); and an arch pressing device (43) comprises a pair of upper arch arms (431) and a pair of lower arch arms (432), upper ends of the upper arch arms (431) are rotatably connected with a central position of a lower portion of the arch pressing device fixing disc (42), lower ends of the upper arch arms (431) are rotatably connected with upper ends of the lower arch arms (432), and lower ends of the lower arch arms (432) are rotatably connected with a central position of an upper portion of a base plate (44). The machine tool can perform multi-site variable-section reaming at different positions and improve the anti-pull-out property of an anchor rod.

Expandable reamers for enlarging a borehole in a subterranean formation include a tubular body, at least one curved blade track carried by the tubular body, and at least one blade engaged with the at least one blade track and configured to slide along the curved blade track along a curved path between a first retracted blade position and a second expanded blade position. To form such an expandable reamer, a tubular body having at least one curved blade track carried by the tubular body may be formed, and at least one blade may be engaged with the blade track. The blade and blade track may be configured such that the blade slides along the blade track along a curved path between a retracted position and an expanded position. Such expandable reamers may be used to enlarge boreholes in subterranean formations.

A wellbore casing cutting tool having multiple expandable cutter bases. The leading or downhole ends of the cutter bases are tapered, forming a tapered nose profile, and are covered with hardened cutting material to form a cutting surface. The cutting surface on the tapered nose profile can be used to remove a cement sheath within a casing string being cut or milled.

An apparatus is positioned within a wellbore in a subterranean formation. The apparatus includes a housing, a guide shaft, a follower, multiple underreamer blades, and a hydraulic chamber. The housing defines a track including multiple catch points. The guide shaft is disposed within the housing. The follower protrudes radially outward form the guide shaft and is received by the track. The follower and the track are cooperatively configured to restrict movement of the guide shaft relative to the housing. A rate of flow to the guide shaft is adjusted to adjust a relative position of the guide shaft with respect to the housing until the follower is located at one of the catch points. A pressure within the hydraulic chamber is adjusted to adjust a level of radially outward protrusion of the underreamer blades. The underreamer blades are rotated to cut into the subterranean formation.