Various drill bits, drilling systems and related methods are provided. In one embodiment, a drill bit comprises a bit body having a face and a shank, at least one insert having a convex engagement surface coupled with the face and at least one wear insert coupled with the shank. In one particular embodiment, the at least one wear insert may be positioned immediately adjacent a coupling end of the shank. The at least one wear insert may include a superabrasive table which may be bonded with a substrate. The at least one wear insert includes a wear surface defined in the superabrasive table. In one embodiment, the superabrasive table may comprise polycrystalline diamond. Similarly, the inset having a convex engagement surface may include a superabrasive material, such as polycrystalline diamond, bonded with a substrate. Such a drill bit may be used, for example, in a top hammer percussion drilling operation.

A drilling machine for a wellbore is provided. The drilling machine may include a dynamic lateral pad that is movable between an extended and retracted position. In the extended position, the pad moves the drill bit in a direction for drilling. The drilling machine may include a dynamic lateral cutter that is movable between an extended and retracted position. In at least the extended position, the cutter engages the wellbore and removes formation. The drilling machine may include a monolithic or integral drill bit/drive shaft to reduce the distance between a positive displacement motor and a distal end of the monolithic or integral drill bit/drive shaft. The drilling machine may include separate cutting structures that have different rotational speeds and can further utilize the integral drill bit/drift shaft and/or a bent housing that generates an off-axis rotation which helps optimize the formation removal in the center area of the wellbore.

A drill bit has a plurality of cutters secured to the bit body, including a gauge cutter defining a gauge diameter of the drill bit. A reciprocating gauge assembly on the bit comprises a cavity defined in the bit body, a piston reciprocably disposed in the cavity, a wear element on an outwardly facing end of the piston, a piston retainer for moveably retaining the piston in the cavity, and a spring biasing the piston outwardly to a neutral position of the wear element with respect to the gauge diameter. The wear element and piston may be urged inwardly in response to an applied load at the drill bit gauge pad, increasing the lateral depth of cut and thereby controlling the aggressiveness of the bit in response to the load.

Various drill bits, drilling systems and related methods are provided. In one embodiment, a drill bit comprises a bit body having a face and a shank, at least one insert having a convex engagement surface coupled with the face and at least one wear insert coupled with the shank. In one particular embodiment, the at least one wear insert may be positioned immediately adjacent a coupling end of the shank. The at least one wear insert may include a superabrasive table which may be bonded with a substrate. The at least one wear insert includes a wear surface defined in the superabrasive table. In one embodiment, the superabrasive table may comprise polycrystalline diamond. Similarly, the inset having a convex engagement surface may include a superabrasive material, such as polycrystalline diamond, bonded with a substrate. Such a drill bit may be used, for example, in a top hammer percussion drilling operation.

A drill bit for removing subterranean formation material in a borehole comprises a bit body comprising a longitudinal axis, a plurality of blades extending radially outward from the longitudinal axis along a face region of the bit body and extending axially along a gauge region of the bit body, and an insert coupled to at least one blade in the gauge region. The insert comprises an elongated body having an upper surface, a lower surface, and a longitudinal axis extending centrally therethrough and intersecting the upper and lower surfaces. The upper surface comprises a bearing surface for supporting for the drill bit and providing a surface on which the subterranean formation being drilled rubs against the insert without exceeding the compressive strength of the selected formation. The insert is coupled to the blade such that the upper surface thereof extends radially beyond an outer surface of the blade and the lower surface thereof extends radially below the outer surface of the blade.

A drill bit assembly for making a hole in a subterranean formation, the drill bit assembly comprising: a connector body defining a centreline axis about which said connector body rotates while drilling; a plurality of blade members connected to the connector body and circumferentially arranged around the centreline axis to form a cutting blade having an outer diameter generally equal to a desired hole diameter, wherein each blade member comprises at least one aperture for receiving a cutting pin; and a removable sleeve positionable within the at least one aperture, the removable sleeve configured to rotatably engage with the at least one cutting pin to allow the at least one cutting pin to rotate within the removable sleeve when the drill bit assembly operates to make the hole in the subterranean formation.

Various drill bits, drilling systems and related methods are provided. In one embodiment, a drill bit comprises a bit body having a face and a shank, at least one insert having a convex engagement surface coupled with the face and at least one wear insert coupled with the shank. In one particular embodiment, the at least one wear insert may be positioned immediately adjacent a coupling end of the shank. The at least one wear insert may include a superabrasive table which may be bonded with a substrate. The at least one wear insert includes a wear surface defined in the superabrasive table. In one embodiment, the superabrasive table may comprise polycrystalline diamond. Similarly, the inset having a convex engagement surface may include a superabrasive material, such as polycrystalline diamond, bonded with a substrate. Such a drill bit may be used, for example, in a top hammer percussion drilling operation.

A downhole assembly includes a bit and a cutting tool uphole of the bit. The cutting tool has one or more expandable cutter arms. The one or more expandable cutter arms include at least one stabilizer portion having a radial position that is about the same as a gauge of the bit when the one or more expandable cutter arms are in an expanded position. A spline on the cutter arms are used by a cutting tool to move the cutter arms.

A drill bit comprises a bit body having a longitudinal axis and a blade extending radially outward from the longitudinal axis along a face region and axially along a gauge region. A gauge region includes a cutting element located proximate to an uphole edge of the blade in the gauge region. A remainder of the gauge region is free of cutting elements mounted thereon. A method of drilling a borehole comprises rotating the bit about the longitudinal axis, engaging a formation with cutting elements mounted to the face region, and increasing a lateral force applied substantially perpendicular to the longitudinal axis such that the cutting element engages the formation and such that side cutting exhibited by the tool is initially minimal and substantially constant and subsequently increases in a substantially linear manner with increasing lateral force.

A rotary drill bit includes movable gauge elements biased to protrude radially through a circumferential engagement surface of a gauge pad. The gauge elements are retractable to protrude a lesser distance against the bias of a biasing mechanism. Fluid chambers are defined adjacent the gauge elements, and fluid is permitted to be bled into and out of the fluid chambers to delay and slow the retraction and extension of the gauge elements. During straight drilling operations, the biasing mechanisms maintain the gauge elements in an extended position providing stability to the drill bit. When a steering force is applied to the drill bit, the gauge elements retract slowly as fluid is bled from the fluid chambers. As the gauge elements rotate with the drill bit, the retracted configuration may be maintained as gauge elements disengage the geologic formation on a side of the drill bit opposite the steering direction.