A percussive rock drill bit has a head and a shank in which a plurality of flushing grooves extend radially outward and axially rearward from a front face. The flushing grooves are configured to optimize the axially rearward flow of rock particles and fines entrained in the flushing fluid. In particular, each groove is generally convex relative to a longitudinal axis of the drill bit and is declined continuously relative to the axis from a first groove end to a second groove end.

A percussive rock drill bit has a head and a shank in which a plurality of flushing grooves extend radially outward and axially rearward from a front face. The flushing grooves are configured to optimize the axially rearward flow of rock particles and fines entrained in the flushing fluid. In particular, each groove is generally convex relative to a longitudinal axis of the drill bit and is declined continuously relative to the axis from a first groove end to a second groove end.

A bidirectional cluster hammer reamer (BCHR) for use in a horizontal direction drilling system comprises a plurality of percussive hammers and bits arranged around a central drive rod. The central drive rod is translatable between a forward most position and a rear most position. The central drive rod is translated to the forward most position when the BCHR is being pulled through a previously drilled pilot channel. The central drive rod is translated to the rear most position when a reverse feed force is applied to the BCHR. When in the rear most position, the central drive rod cooperates with an air distribution assembly at the rear of the BCHR to expel a portion of a pressurized fluid to the exterior of the BCHR for clearing accreted debris.

A bidirectional cluster hammer reamer (BCHR) for use in a horizontal direction drilling system comprises a plurality of percussive hammers and bits arranged around a central drive rod. The central drive rod is translatable between a forward most position and a rear most position. The central drive rod is translated to the forward most position when the BCHR is being pulled through a previously drilled pilot channel. The central drive rod is translated to the rear most position when a reverse feed force is applied to the BCHR. When in the rear most position, the central drive rod cooperates with an air distribution assembly at the rear of the BCHR to expel a portion of a pressurized fluid to the exterior of the BCHR for clearing accreted debris.

For clearing of the bore liners of geothermal wells, disclosed is a clearing tool that can be used without a drive motor, but with a drive hammer, to clear mineral deposits from the inside of the bore liners of geothermal wells. A forward end clears unwanted material from a live well. An aft end engages with a hammer device. The tool also has working surfaces to bear against and to cut through or to break up the unwanted material, at least one bypass passage conveying fluid from the live well through the clearing tool, and at least one exhaust passage communicating with the hammer device and conveying exhaust gases from the hammer to exhaust exit ports. The location of at least one exhaust exit port is a location that is situated aft of a forward face of the forward end of the clearing tool.

A self-directing nozzle of a drill bit of a downhole tool and method are disclosed. The drill bit with the nozzle may be used to form a wellbore in a subterranean formation. The drill bit has a passage for fluid to pass through. The nozzle includes a case positionable in the passage of the drill bit and a movable body movably positionable in the case. The movable body has a channel for passage of the fluid therethrough. The channel has a non-linear shape with a channel axis extending therethrough. The channel axis is curved to define a spiral flow path therethrough whereby the fluid passing through the channel facilitates rotation of the movable body within the passage of the drill bit.

A self-directing nozzle of a drill bit of a downhole tool and method are disclosed. The drill bit with the nozzle may be used to form a wellbore in a subterranean formation. The drill bit has a passage for fluid to pass through. The nozzle includes a case positionable in the passage of the drill bit and a movable body movably positionable in the case. The movable body has a channel for passage of the fluid therethrough. The channel has a non-linear shape with a channel axis extending therethrough. The channel axis is curved to define a spiral flow path therethrough whereby the fluid passing through the channel facilitates rotation of the movable body within the passage of the drill bit.

A down-the-hole drilling device, being meant for drilling a hole with and a casing part is described. The drilling device comprises in its drilling head: a drilling arrangement, having first drilling means for drilling a center hole and second drilling means for reaming the center hole for the casing part; and a flushing flow arrangement for feeding of a flushing medium onto a drilling surface of the drilling arrangement by one or more feed channels and for discharging the same from the drilling surface together with drilling waste. The casing part is arranged to be pulled into the hole to be drilled by power influence directed thereto from the drilling arrangement. A feed channel of the flushing flow arrangement at least partly ends up on the drilling surface at a flushing channel that exists in the longitudinal direction of the drilling device essentially behind a rearmost part of the drilling surface of at least of the first drilling means. The flushing flow arrangement comprises on the bottom of the flushing channel a supplementary flushing groove that extends from the feed channel towards the outer periphery of the drilling arrangement.

A drill bit, drill bit assembly and related methods of manufacture as disclosed involve a head portion having a circumference and a face surface, and a shank portion extending longitudinally from a side of the head portion opposite to the face surface. A central flushing channel extends longitudinally through the shank portion and a distance within the head portion, and a lateral flushing channel extends from the central flushing channel to the circumference of the head portion. A first portion of the lateral flushing channel is inclined, in a flushing fluid flowing direction, towards the face surface with respect to said second portion, and correspondingly, a second portion is inclined, in a flushing fluid flowing direction, towards the shank portion.

A drill bit, drill bit assembly and related methods of manufacture as disclosed involve a head portion having a circumference and a face surface, and a shank portion extending longitudinally from a side of the head portion opposite to the face surface. A central flushing channel extends longitudinally through the shank portion and a distance within the head portion, and a lateral flushing channel extends from the central flushing channel to the circumference of the head portion. A first portion of the lateral flushing channel is inclined, in a flushing fluid flowing direction, towards the face surface with respect to said second portion, and correspondingly, a second portion is inclined, in a flushing fluid flowing direction, towards the shank portion.