Based on measurements of forces and rotational velocity experienced by a drill bit during drilling, drilling behavior is detected and identified. Measurements of forces on a drill bit including torque on bit (TOB), weight on bit (WOB), etc. and measurements of rotational velocity (rotations per minute or RPM) are acquired in real time at the drill bit. Various measurements are correlated to produce related combinations of measurements, such as WOB-RPM, TOB-RPM, and RPM-time. Based on fitting between the combinations of measurements and curves corresponding to predetermined torsional behavior trends, torsional, axial, and rotational behaviors are classified as functional or dysfunctional. A dysfunction identifier then identifies drill bit dysfunctions, such as high-frequency torsional noise, cutting-induced stick-slip, friction-inducted stick-slip, pipe-induced stick-slip, three-dimensional (3D) coupled vibrations (including subsets high-frequency torsional oscillations and low-frequency torsional oscillations), low-frequency torsional vibration, high-frequency torsional vibration, etc.) based on the functionality of the torsional, axial, and rotational behaviors. Based on drill bit dysfunction identification, dysfunctional drilling behavior can be mitigated.

A rock-piercing flexible rock drilling robot and a rock breaking method therefor are disclosed. The robot includes a control system, a head, and at least one tail. The head includes a head housing, a propulsion turntable, a drilling mechanism, a hydraulic propulsion system, a first driving mechanism, and a second driving mechanism. The propulsion turntable includes a drill bit located at a center thereof and a cutting turntable arranged around the drill bit. The first driving mechanism is connected to the drill bit, and the second driving mechanism is connected to the cutting turntable. The tail includes a tail housing, an advancing and retreating power system, and a fixed support system. The head and the tail are connected through a flexible component, and the tails are connected through flexible components.

An underground transmitter can be configured for use with a drill head and configured for wireless communication. The underground transmitter can include a control circuitry and a multi-coil antenna assembly. The control circuitry is configured for transmitting data associated with an operation of the drill head. The multi-core antenna can include an antenna core and a plurality of distinct wire coils. The plurality of distinct wire coils can be positioned proximate (e.g., around) the antenna core, with the distinct wire coils each having a different inductance associated therewith and thereby capable of transmitting in a separate frequency range. The control circuitry can be selectably coupled with the distinct wire coils to control which of the distinct wire coils are activated and thereby generating data signals at a given time.

Based on measurements of forces and rotational velocity experienced by a drill bit during drilling, drilling behavior is detected and identified. Measurements of forces on a drill bit including torque on bit (TOB), weight on bit (WOB), etc. and measurements of rotational velocity (rotations per minute or RPM) are acquired in real time at the drill bit. Various measurements are correlated to produce related combinations of measurements, such as WOB-RPM, TOB-RPM, and RPM-time. Based on fitting between the combinations of measurements and curves corresponding to predetermined torsional behavior trends, torsional, axial, and rotational behaviors are classified as functional or dysfunctional. A dysfunction identifier then identifies drill bit dysfunctions, such as high-frequency torsional noise, cutting-induced stick-slip, friction-inducted stick-slip, pipe-induced stick-slip, three-dimensional (3D) coupled vibrations (including subsets high-frequency torsional oscillations and low-frequency torsional oscillations), low-frequency torsional vibration, high-frequency torsional vibration, etc.) based on the functionality of the torsional, axial, and rotational behaviors. Based on drill bit dysfunction identification, dysfunctional drilling behavior can be mitigated.

A modular compaction boring device. The boring device comprises a compaction boring head which creates a borehole through a subsurface by operation of a thruster and a rear and forward anchor. Extension of the thruster while the rear anchors are engaged move the boring head forward. Retraction of the thruster while the forward anchors are engaged brings the rear anchors forward for an addition stroke. A steering geometry in the boring head and rotation of the boring head allow steering of the boring device. Steering, thrust, and anchors may be controlled remotely through an umbilical cable pulled through the borehole by the boring device.

A system and for providing a bore sight in a piercing tool. A transmitter emits a magnetic field. The flux lines which emanate along the transmitter axis are substantially straight. A receiver at a remote, target location can detect these flux lines. The receiver and transmitter are oriented such that the substantially straight flux line are along an intended bore path. Then, a piercing tool or other boring tool is oriented along the same path and a bore is created.

A method comprises acquiring measurements of a force and a rotational velocity experienced by a drill bit while the drill bit is positioned in a wellbore; and identifying, by at least one processor, a type of dysfunction experienced by the drill bit based on a relationship of the measurement of the force and a measurement of the rotational velocity.

A connection system for a lid in a beacon housing. The lid is connected to the housing at a tab at a first end, after a lip of the lid is placed under a shelf at its second end. The tab has a cross-bore for receiving a connection pin through both the cross-bore and corresponding holes in the housing which form a continuous passage. The lid is placed under tension to reduce relative vibration between the lid and the housing. A set screw is placed within the tab to place a force on the connection pin. Further set screws are distributed about the lid and place the lid in tension relative to the housing. The lid can be removed by reducing the tension provided by the set screws, removing the connection pin, and adjusting the lid such that it is no longer under the shelf of the housing.

A wireless data telemetry system for use in a drilling system can include a drill head wireless transmitter and at least one data link transceiver. The drill head wireless transmitter can be in a drill head of the drilling system, the drill head wireless transmitter configured to generate and transmit one or more data signals associated with a drilling process. The at least one data link transceiver can be wirelessly coupled to at least one of the drill head wireless transmitter or another data link transceiver, with the drill head wireless transmitter and the at least one data link transceiver configured to be physically coupled within a drill string and spaced apart from one another. The drill head wireless transmitter and the at least one data link transceiver together configured to wirelessly communicate the one or more data signals beyond a transmission range of the drill head wireless transmitter.

A system and for providing a bore sight in a piercing tool. A transmitter emits a magnetic field. The flux lines which emanate along the transmitter axis are substantially straight. A receiver at a remote, target location can detect these flux lines. The receiver and transmitter are oriented such that the substantially straight flux line are along an intended bore path. Then, a piercing tool or other boring tool is oriented along the same path and a bore is created.