A transmitter for inground use controls a depth signal transmit power in relation to a data signal transmit power such that one reception range of the depth signal at least approximately matches another, different reception range of the data signal. A portable device can form a system with the transmitter in which the portable device scans a plurality of frequencies within at least one low frequency depth signal range to measure the electromagnetic noise at each one of the plurality of frequencies and identify at least one of the frequencies as a potential depth frequency for the transmitter. The portable device can include a dual mode filter having a rebar mode and a normal mode filter. The depth signal frequency is dynamically positionable in relation to low frequency noise.

A horizontal directional drilling method includes operation of a HDD machine to power a drill string terminating at a drill head to create an underground borehole extending at least partially horizontally between an entry point and an exit point. A utility line and a pair of insulated wires are attached to the drill string at the exit point. An observation device is also attached to the drill string, and the observation device is connected with an uphole module via power line communication (PLC) over the pair of insulated wires. The horizontal directional drilling machine performs a pullback of the drill string, with the utility line, the pair of insulated wires, and the observation device connected thereto, back toward the entry point. Data from the observation device are displayed on the uphole module during pullback of the drill string.

A perforating gun for use in oil and gas operations. The gun is carried to a desired area of a wellbore using only fluid pressure. The gun comprises a charge housing disposed within a removable sleeve. The charge housing comprises a plurality of shaped charges in communication with one or more sensors. The sensors are programmed to initiate the detonation sequence of the shaped charges upon measuring set parameters. Upon detonation, the gun fragments into a plurality of pieces that may be washed away from the detonation site.

Couplers for connecting a power source to a drilling string are disclosed. The coupler may include an elongate assembly including a first portion and a second portion. The first portion and the second portion are configured to move relative to each other such that the coupler may be arranged in a retracted position, an extended position, and one or more intermediate positions. In the retracted position, the coupler may transmit a compressive force and/or a torque to the drilling string. In the extended position, the coupler may transmit a tensile force and/or a torque to the drilling string. In the intermediate positions, the first portion and the second portion are able to translate and rotate independently relative to each other.

A method for building a dual-member drill string comprising an inner drill string and an outer drill string. Inner pipe sections are connected using non-threaded connections, while outer pipe sections are connected using threaded connections. A new inner pipe section is rotated in a first direction until the inner pipe section applies torque to the existing inner pipe string. If the magnitude of the torque applied to the inner pipe string exceeds a pre-determined threshold value, the inner pipe section is automatically rotated in an opposite second direction. The inner pipe section rotates between opposite directions, once torque is sensed in each direction, until the inner pipe section is coupled to the inner pipe string.

A drill assembly (10) for use in trenchless subterranean boring, comprising: a drill shoe (20) having a body with a posterior portion (30) and an anterior portion (22), the latter defining a recess while the former comprises drill bits (32) disposed on a front end (34), opposing lateral sides, and flanks to assist the shoe (20) in acting as both pilot bore drilling tool and as reaming tool; a drill head (50) demount ably mounted to tire drill shoe (20) via tire recess and in communication with directional guidance means; a string of connectable drill rods (80), having a bailing end (82) and a leading end (84) when connected, and through which a drilling solution can be pumped towards tire drill shoe (20); a coupling (86) for linking tire leading end (84) to said drill head (50); and a connector (88) for connecting the trailing end (82) to a vehicle. The invention extends to a drill shoe (20) and a method of use and manufacture thereof.

The invention relates to a control for at least one retainer of a transfer device for a rod section of a ground drilling device, wherein the ground drilling device is configured for moving a drill string, and the transfer device is configured for transferring the received rod section from a position in a rod magazine to a position on the drill string or vice versa, and the control is configured to move the retainer between a position above the rod magazine and the position on the drill string while the drill string is still moving.

In an embodiment, the present system can primarily determine the pilot bore profile of a horizontal directional drill (HDD) based on the number of rod sections added and the pitch reading from the underground transmitter at the front of the drill string (as communicated to the HDD drill rig via the walk-over locator), with such calculations being able to be made at the HDD drill rig and/or related remote display on the HDD drill rig. That is, since the length of a given rod section is known and the pitch readout is provided by the underground transmitter, the change in the overall depth of the drill string can be calculated, for example, on drill rod to drill rod basis based on rise over run geometry. The walk-over locator can then be used for a secondary confirmation of the actual depth, if conditions permit (e.g., in range of a direct walk-over).

A cutting head has a mounting bracket for attachment to a pipe and a cutter wheel. A double tapered bearing is connected between the mounting bracket and the cutter wheel. The bearing allows the cutter wheel to be rotated without rotation of the pipe. A drive shaft connector on the cutter wheel is connectable to a pilot hole drive shaft for rotating the cutter wheel and pulling it and the pipe. A pilot hole is drilled in a conventional manner. The pipe is attached to the mounting bracket and an end of the pilot hole drive shaft is then connected to the cutter wheel. Simultaneously the pilot hole is enlarged and the pipe and cutter wheel are pulled along the enlarged hole by the drive shaft. The cutter wheel advances along the pilot hole and the pipe is simultaneously advanced through the enlarged hole immediately behind the cutter wheel.

A spallation drill head can include a drill head body having a primary face substantially oriented facing in a primary drilling direction along a longitudinal axis of the drill head body. A liquid inlet can be on the drill head body. The liquid inlet can be connected or connectable to a liquid supply line. An internal liquid connection can be oriented within the drill head body and fluidly connected to the liquid inlet. A plurality of liquid jets can be oriented on the primary face of the drill head. The liquid jets can be fed by the liquid inlet through the internal liquid connection. A mass flow controller can be associated with the liquid jets to control delivery of liquid by the liquid jet, and flowrates to at least two of the liquid jets can be independently controllable.