A downhole oscillation tool and method for axially vibrating a drill bit. In some embodiments, modular actuation assemblies may be provided, which may be readily interchanged between a housing and a shaft to axially vibrate the shaft with respect to the housing. Modular actuation assemblies may be mechanical, hydraulic, electric, or piezoelectric, for example, and may be characterized by differing oscillation frequencies. In some embodiments, a piezo element may be provided between the housing and the shaft.

A logging tool electronics system is disclosed with noise minimization features and pulse compression signal processing techniques to improve the signal-to-noise ratio of array induction logging tools. The borehole is radiated with a magnetic field produced by a configurable multi-frequency and/or multi-amplitude sine wave signal stimulus section driving a fully differential single transmitter coil. Received signals from multiple mutually balanced fully differential receiver arrays are processed by receiver signal chains using adaptive algorithms under firmware control. The received signals are used to determine the conductivity and resistivity of the formation surrounding the borehole.

A logging tool electronics system is disclosed with noise minimization features and pulse compression signal processing techniques to improve the signal-to-noise ratio of array induction logging tools. The borehole is radiated with a magnetic field produced by a configurable multi-frequency and/or multi-amplitude sine wave signal stimulus section driving a fully differential single transmitter coil. Received signals from multiple mutually balanced fully differential receiver arrays are processed by receiver signal chains using adaptive algorithms under firmware control. The received signals are used to determine the conductivity and resistivity of the formation surrounding the borehole.

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.

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 assembly for percussive drilling, comprising a drill bit and a percussion device. The drill assembly further includes a hollow cylindrical foot valve partially received within a first central flushing channel thereof and extending therefrom in the uphole direction, such that the foot valve is also partially received within a central recess of an impact piston of the percussion device, at least when the impact piston is in a lowermost position of its reciprocation cycle, and such that the foot valve is no longer received within the central recess, at least when the impact piston is in an uppermost position of its reciprocation cycle. The foot valve includes an internal stiffener extending radially inwardly from at least two circumferential positions of an inner surface of the foot valve.

In a method for identifying a deflection or a breakdown of a machine tool, in particular a hand-held machine tool, with an oscillating output movement, in particular a linearly oscillating output movement, at least one physical characteristic of the machine tool, in particular of a motor, a powertrain component, and/or a machining tool of the machine tool, is detected continuously or periodically by means of a detection unit. The method further includes detecting a deflection or a breakdown of the machine tool with an analysis unit on the basis of at least two values, which are identified at different times, of the characteristic of the machine tool, wherein each of the at least two values of the characteristic are associated with at least one respective substantially identical value of a discrete position characteristic of the oscillating output movement, in particular the linearly oscillating output movement, of the machine tool.

A flushing system in a drill bit, which has a body that defines the flushing system, can include an inlet to facilitate supply of pressurized fluids into a bore hole. A cutting surface of the drill bit is provided with a main opening that defines a main passageway in communication with the inlet. A peripheral surface of the drill bit is provided with a secondary opening that defines a secondary passageway in communication with the inlet. The secondary passageway is disposed at an angle from a horizontal reference plane. The horizontal reference plane is defined between the inlet and the origin of the main passageway and is perpendicular to a central longitudinal axis of the body of the drill bit. An origin of the secondary passageway is at a distance from the origin of the main passageway.

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 rotary percussive hydraulic drill including: a body, a shank intended to be coupled to at least one drilling bar equipped with a tool, the shank including a coupling part comprising female coupling splines and male coupling splines which are angularly offset from each other with respect to an extension axis of the shank, a striking piston slidably mounted inside the body along a striking axis and configured to strike the shank, a rotation driving device which is configured to drive the shank in rotation about an axis of rotation substantially coincident with the striking axis, the rotation driving device comprising a coupling member disposed around the shank, the coupling member comprising male coupling splines and female coupling splines which are respectively rotatably coupled with the female and male coupling splines of the shank a front abutment surface which is fixed with respect to the body, the front abutment surfacebeing annular and extending around the shank, the shank being configured to abut against the front abutment surface so as to limit a displacement stroke of the shank forwards, wherein the shank includes an annular bearing flange which is provided on an outer surface of the shank and which includes an annular bearing surfaceconfigured to abut against the front abutment surface, and wherein each of the female and male coupling splines provided on the shank extends from the annular bearing flange and in the direction of the striking piston, each female coupling spline provided on the shank including a bottom surface and a connecting surface which connects the respective bottom surface to the annular bearing flange and which extends forwards away from the extension axis of the shank, the connecting surface of each female coupling spline provided on the shank being at least in part formed by a curved concave surface extending substantially in the extension direction of the respective female coupling spline and having a radius of curvature which is less than the radial height of each of the male coupling splines provided on the shank.