A shaft enlargement arrangement for a boring system comprises a hollow column proximate a lower end of the boring system. A reamer section comprising a downwardly tapering first cutter head arrangement is rotatably fitted to the hollow column, with a first drive being provided to rotate the first cutter head arrangement relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to the diameter of the first cutter head arrangement. A boring head arrangement is fitted to an operatively lower end, the boring head arrangement terminating in a downwardly tapering second cutter head arrangement to bore a leading or pilot hole, having a diameter that is less than the diameter of the first cutter head arrangement, as the boring system proceeds to bore downwardly.

A hole opener configured for use with a directional drilling rig and the hole opener includes a shaft and slots that extends along the shaft. Blades extend radially outward from the shaft and are each received within one of the slots to couple the blades to the shaft for rotation with the shaft and to space the blades apart around the shaft. The hole opener further includes saddles. Each of the saddles includes a slot that receives one of the blades to couple the saddle to the blade and the shaft for rotation with the blade and the shaft. The saddles each include a recess. The hole opener further includes cutters and each of the cutters is received within one of the recesses of the saddles to couple the cutters to the shaft for rotation with the shaft and to space the cutters around the longitudinal axis of the shaft.

A hole opener configured for use with a directional drilling rig and the hole opener includes a shaft and slots that extends along the shaft. Blades extend radially outward from the shaft and are each received within one of the slots to couple the blades to the shaft for rotation with the shaft and to space the blades apart around the shaft. The hole opener further includes saddles. Each of the saddles includes a slot that receives one of the blades to couple the saddle to the blade and the shaft for rotation with the blade and the shaft. The saddles each include a recess. The hole opener further includes cutters and each of the cutters is received within one of the recesses of the saddles to couple the cutters to the shaft for rotation with the shaft and to space the cutters around the longitudinal axis of the shaft.

A downhole tool, for selectively reaming a wellbore or stabilizing drill string components within a wellbore, includes an elongate tool body adapted to receive reamer cartridges or stabilizer cartridges depending. The reamer cartridges are radially insertable into corresponding pockets in the tool body, with each reamer cartridge having a reamer insert with an array of cutting elements. The reamer insert is disposed within a bushing and is rotatable relative thereto, about a rotational axis transverse to the longitudinal axis of the tool. However, the rotational axis is offset from the tool body axis, resulting in eccentric contact of the cutting elements with the wall of the wellbore, which in turn imparts rotation to the reamer insert when the tool is moved axially through a wellbore without rotation. When the tool is used for stabilization, the reamer cartridges are removed and replaced with stabilizer cartridges having stabilizer inserts with hard-faced stabilizer cones.

A downhole tool, for selectively reaming a wellbore or stabilizing drill string components within a wellbore, includes an elongate tool body adapted to receive reamer cartridges or stabilizer cartridges depending. The reamer cartridges are radially insertable into corresponding pockets in the tool body, with each reamer cartridge having a reamer insert with an array of cutting elements. The reamer insert is disposed within a bushing and is rotatable relative thereto, about a rotational axis transverse to the longitudinal axis of the tool. However, the rotational axis is offset from the tool body axis, resulting in eccentric contact of the cutting elements with the wall of the wellbore, which in turn imparts rotation to the reamer insert when the tool is moved axially through a wellbore without rotation. When the tool is used for stabilization, the reamer cartridges are removed and replaced with stabilizer cartridges having stabilizer inserts with hard-faced stabilizer cones.

A downhole tool, for selectively reaming a wellbore or stabilizing drill string components within a wellbore, includes an elongate tool body adapted to receive reamer cartridges or stabilizer cartridges. The reamer cartridges are radially insertable into corresponding pockets in the tool body, with each reamer cartridge having a reamer insert with an array of cutting elements. The reamer insert is disposed within a bushing and is rotatable relative thereto, about a rotational axis transverse to the longitudinal axis of the tool. However, the rotational axis is offset from the tool body axis, resulting in eccentric contact of the cutting elements with the wall of the wellbore. This imparts rotation to the reamer insert when the tool is being-moved axially through a wellbore without rotation. When the tool is to be used for stabilization, the reamer cartridges are removed and replaced with stabilizer cartridges having stabilizer inserts with hard-faced stabilizer cones.

A downhole tool, for selectively reaming a wellbore or stabilizing drill string components within a wellbore, includes an elongate tool body adapted to receive reamer cartridges or stabilizer cartridges. The reamer cartridges are radially insertable into corresponding pockets in the tool body, with each reamer cartridge having a reamer insert with an array of cutting elements. The reamer insert is disposed within a bushing and is rotatable relative thereto, about a rotational axis transverse to the longitudinal axis of the tool. However, the rotational axis is offset from the tool body axis, resulting in eccentric contact of the cutting elements with the wall of the wellbore. This imparts rotation to the reamer insert when the tool is being-moved axially through a wellbore without rotation. When the tool is to be used for stabilization, the reamer cartridges are removed and replaced with stabilizer cartridges having stabilizer inserts with hard-faced stabilizer cones.

A hole opener includes a body with cone arms. The body includes pockets formed in the body in which each of the pockets includes a forwardly-positioned shoulder pocket section, a rearwardly-positioned tapered pocket section and a base opening axially extending through a wall of the corresponding pocket that receives a fastener therethrough. The cone arms each include a cone head attached to an arm. The arm includes a forwardly-positioned shoulder arm section, a rearwardly-positioned tapered arm section, and a rearwardly-facing opening axially extending through the rearwardly-positioned tapered arm section that receives the fastener. When each of the cone arms is inserted into a corresponding one of the pockets and the corresponding fastener(s) is/are tightened, the rearwardly-positioned tapered arm section is securely drawn into the rearwardly-positioned tapered pocket section of the pocket to create a pre-loaded fit therebetween and the forwardly-positioned shoulder arm section mates with the forwardly-positioned shoulder pocket section.

A hole opener includes a body with cone arms. The body includes pockets formed in the body in which each of the pockets includes a forwardly-positioned shoulder pocket section, a rearwardly-positioned tapered pocket section and a base opening axially extending through a wall of the corresponding pocket that receives a fastener therethrough. The cone arms each include a cone head attached to an arm. The arm includes a forwardly-positioned shoulder arm section, a rearwardly-positioned tapered arm section, and a rearwardly-facing opening axially extending through the rearwardly-positioned tapered arm section that receives the fastener. When each of the cone arms is inserted into a corresponding one of the pockets and the corresponding fastener(s) is/are tightened, the rearwardly-positioned tapered arm section is securely drawn into the rearwardly-positioned tapered pocket section of the pocket to create a pre-loaded fit therebetween and the forwardly-positioned shoulder arm section mates with the forwardly-positioned shoulder pocket section.

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.