A drilling apparatus including a rotary cutting tool having a proximal end and a distal end and further defining a rotary axis generally extending between the proximal and distal ends. The rotary cutting tool includes a proximally directed face located between the proximal and distal ends that face mainly in a proximal direction. The rotary cutting tool also includes an angled mounting face that extends between the proximally directed face and the proximal end. The angled mounting face is angled relative to the proximally directed face and the rotary axis where one of a mounting aperture and a mounting protrusion are provided at the proximally directed face. The one of the mounting aperture and the mounting protrusion have a mounting depth that extends generally in the direction of the rotary axis. The distal end includes a feature that is configured for at least one of cutting and grinding.

A drilling apparatus including a rotary cutting tool having a proximal end and a distal end and further defining a rotary axis generally extending between the proximal and distal ends. The rotary cutting tool includes a proximally directed face located between the proximal and distal ends that face mainly in a proximal direction. The rotary cutting tool also includes an angled mounting face that extends between the proximally directed face and the proximal end. The angled mounting face is angled relative to the proximally directed face and the rotary axis where one of a mounting aperture and a mounting protrusion are provided at the proximally directed face. The one of the mounting aperture and the mounting protrusion have a mounting depth that extends generally in the direction of the rotary axis. The distal end includes a feature that is configured for at least one of cutting and grinding.

An apparatus for horizontal directional drilling includes a housing and a sonde transmitter mounted in the housing. The housing includes a main fluid channel to permit a flow of a fluid therethrough. The apparatus further includes a fluid outlet at the front of the housing in communication with the main fluid channel and adapted to emit fluid. from the front of the housing during pilot bore operations. The housing further includes a plurality of fluid ports in fluid communication with the main fluid channel and adapted to emit fluid from the housing during pullback operations. Drill bits, drill bit adapters adapters, swivel connectors, and tow heads adapted to be coupled to the drill bits for direct pullback operations, as well as methods of direct pullback operations during horizontal direction drilling are also provided.

An apparatus for horizontal directional drilling includes a housing and a sonde transmitter mounted in the housing. The housing includes a main fluid channel to permit a flow of a fluid therethrough. The apparatus further includes a fluid outlet at the front of the housing in communication with the main fluid channel and adapted to emit fluid. from the front of the housing during pilot bore operations. The housing further includes a plurality of fluid ports in fluid communication with the main fluid channel and adapted to emit fluid from the housing during pullback operations. Drill bits, drill bit adapters adapters, swivel connectors, and tow heads adapted to be coupled to the drill bits for direct pullback operations, as well as methods of direct pullback operations during horizontal direction drilling are also provided.

A fixed-cutter earth-boring tool includes a first blade substantially comprising a first material having a first elastic modulus at a temperature, and a second blade substantially comprising a second material having a second elastic modulus at the temperature. The second elastic modulus is different from the first elastic modulus. A method of forming an earth-boring tool includes forming a bit body having a plurality of blades, and providing at least one cutting element on at least one of the plurality of blades. Some fixed-cutter earth-boring drill bits include a first blade exhibiting a first deflection when subjected to a load, and a second blade exhibiting a second deflection when subjected to the load. The first deflection may be a continuous function of the load, and the second deflection may be a discontinuous function of the load.

A replaceable tool support is disclosed. The tool support may be configured to be mounted to a base member of a cutting head, which may be mountable to a tool drum used in hard rock mining applications. The tool support may have an annular body having a first end face side. The tool support may also have a plurality of cutting bit carriers disposed spaced apart from each other on the first end face side. In addition, the tool support may have a plurality of cutting bits. Each of the plurality of cutting bits may be rotatably supported by one of the plurality of cutting bit carriers.

A downhole drilling tool, forming part of a subterranean drilling system, may include at least one plate secured to an exterior of an elongate body. Electronics may be disposed between the plate and the body to be protected by the plate while still readily accessible. A dynamic element may be radially extendable from the plate to engage an inner wall of a borehole being drilled. If this radially-extendable element becomes worn or damaged from this engagement, the plate may be replaced. More expensive components of the drilling tool may be contained within the elongate body, rather than the plate, thus reducing replacement frequency. Additionally, plates including unique features may be employed at different times without altering the underlying elongate body.

A downhole drilling tool, forming part of a subterranean drilling system, may include at least one plate secured to an exterior of an elongate body. Electronics may be disposed between the plate and the body to be protected by the plate while still readily accessible. A dynamic element may be radially extendable from the plate to engage an inner wall of a borehole being drilled. If this radially-extendable element becomes worn or damaged from this engagement, the plate may be replaced. More expensive components of the drilling tool may be contained within the elongate body, rather than the plate, thus reducing replacement frequency. Additionally, plates including unique features may be employed at different times without altering the underlying elongate body.

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.

A method includes acquiring an image of a cutter on a drill bit, determining a cutter dull condition based on the image of the cutter using a machine-learning method, wherein the machine-learning method is trained using a set of training images and a set of known cutter dull conditions, wherein each of the set of known cutter dull conditions is associated with one or more of a set of cutters depicted in the set of training images and determining a cutter degradation severity based the image of the cutter. The method also includes generating bit modification instructions based the cutter dull condition and the cutter degradation severity.