A bearing system configured for use on a downhole tool including a rolling cutter member having a plurality of cutting structures thereon comprises a first plurality of bearings disposed between a head washer and an at least substantially planar shaft washer, and a second plurality of bearings disposed between the at least substantially planar shaft washer and a rolling cutter washer. A downhole tool, such as an earth-boring rotary rolling cutter drill bit includes such a bearing system between a rolling cutter and a head of a bit body. Methods of forming such a downhole tool include the assembly of such a bearing system between a rolling cutter and a head of a bit body.

A bearing system configured for use on a downhole tool including a rolling cutter member having a plurality of cutting structures thereon comprises a first plurality of bearings disposed between a head washer and an at least substantially planar shaft washer, and a second plurality of bearings disposed between the at least substantially planar shaft washer and a rolling cutter washer. A downhole tool, such as an earth-boring rotary rolling cutter drill bit includes such a bearing system between a rolling cutter and a head of a bit body. Methods of forming such a downhole tool include the assembly of such a bearing system between a rolling cutter and a head of a bit body.

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, 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. 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 can be 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, 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. 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 can be replaced with stabilizer cartridges having stabilizer inserts with hard-faced stabilizer cones.

An apparatus and method for drilling an underground borehole where pressurized air may be used to discharge cuttings produced by a cutting assembly. The cutting assembly includes a shaft having a first and second ends and a bore extending between the ends. First and second cutting heads are provided on the shaft a distance apart. The second cutting head is rearward of the first cutting head and is of a greater diameter. Each cutting head defines an air passage therethrough that is in fluid communication with the shaft's bore. A housing extends rearwardly from the second cutting head and connects to a length of casing. An annular flange, concentric with the housing, seals the borehole as the cutting assembly rotates and moves forward through the ground. Cuttings generated by the assembly are moved therethrough and discharged from the casing by pressurized air provided to the assembly through the shaft's bore.

An apparatus and method for drilling an underground borehole where pressurized air may be used to discharge cuttings produced by a cutting assembly. The cutting assembly includes a shaft having a first and second ends and a bore extending between the ends. First and second cutting heads are provided on the shaft a distance apart. The second cutting head is rearward of the first cutting head and is of a greater diameter. Each cutting head defines an air passage therethrough that is in fluid communication with the shaft's bore. A housing extends rearwardly from the second cutting head and connects to a length of casing. An annular flange, concentric with the housing, seals the borehole as the cutting assembly rotates and moves forward through the ground. Cuttings generated by the assembly are moved therethrough and discharged from the casing by pressurized air provided to the assembly through the shaft's bore.

A method and system for a hole opener are provided. The hole opener includes a shaft including a plurality of axial slots formed in an outer periphery and spaced circumferentially about the shaft, a plate coupled to the outer periphery between each pair of slots, the plate including fastening wings that extend radially outwardly from each circumferential end of the plate, and a blade extending radially outwardly from a respective one of the plurality of axial slots between a fastening wing of each of adjacent plates, the blade coupled to each fastening wing.

A method and system for a hole opener are provided. The hole opener includes a shaft including a plurality of axial slots formed in an outer periphery and spaced circumferentially about the shaft, a plate coupled to the outer periphery between each pair of slots, the plate including fastening wings that extend radially outwardly from each circumferential end of the plate, and a blade extending radially outwardly from a respective one of the plurality of axial slots between a fastening wing of each of adjacent plates, the blade coupled to each fastening wing.

Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a sweet spot position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the sweet spot of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a sweet spot position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the sweet spot of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.