An insert for installation on an inner pipe member of a dual-pipe member assembly. The insert is interposed between an external shoulder formed on the inner pipe member and an internal shoulder formed in an outer pipe member. Shoulder-to-shoulder impacts between pipe members results in wear to the insert, rather than to either pipe member. The insert has the shape of an unclosed loop and is positioned within an endless external groove formed in the inner pipe member.

The invention relates to a double head drilling device for a drill rod having an outer pipe and an inner rod running at least in sections inside the outer pipe, with a first drive unit for driving the inner rod in a rotating manner and a second drive unit for driving the outer pipe in a rotating manner. According to the invention provision is made in that for the releasable clamping of the inner rod a first clamping head and a second clamping head are provided and in that the two clamping heads are supported in an axially displaceable manner with respect to each other. Furthermore, the invention also comprises a method for producing a bore with this double head drilling device.

A ground drilling device with a drivetrain for rotating a drill string, wherein at least one section of the drivetrain is configured to form a channel between a force transmission element of the drivetrain and the drill string, wherein the channel projects through the force transmission element and the force transmission element may be driven radially in the drivetrain.

An assembly for a torque-transmitting connection in an inner pipe string of a dual-member drill string is formed from a collar, a retaining ring, and an inner pipe member. An endless internal groove having adjacent shallow and deep sections is formed in the collar. Formed in the inner pipe member, an external grooved region is situated in adjacent relationship with the internal groove. The retaining ring, situated within the grooves, resists disconnection of the collar from the inner pipe member. When the assembly is subjected to an axial force that might otherwise tend to pull it apart, the retaining ring resists the tendency by wedging between the bottom of the shallow section of the internal groove and the crest of the external groove.

A rock drilling arrangement, rock drilling rig and drilling method is provided. The rock drilling arrangement includes a drilling boom, which is mountable to a carrier of the rock drilling rig. The boom is provided with two rock drilling units arranged movably in the longitudinal direction of the boom. Further, the drilling units may be moved independently relative to each other.

A screw anchor for a trussed foundation system to support single-axis trackers and other structures and related methods of driving such a screw anchor into underlying ground. A hollowed tube of uniform diameter is open at both ends with a thread form beginning at one end and circumscribing a portion the tube, the thread form having a tapered lead-in. The open-ended geometry allows a mandrel or rock drill to be inserted and operated through the anchor during driving to expedite the driving process. The tapered thread form provides a lead-in for driving the anchor into a rock bore.

A screw anchor for a trussed foundation system to support single-axis trackers and other structures and related methods of driving such a screw anchor into underlying ground. A hollowed tube of uniform diameter is open at both ends with a thread form beginning at one end and circumscribing a portion the tube, the thread form having a tapered lead-in. The open-ended geometry allows a mandrel or rock drill to be inserted and operated through the anchor during driving to expedite the driving process. The tapered thread form provides a lead-in for driving the anchor into a rock bore.

A horizontal directional drilling system includes a drill head that includes a drive coupling with a central bore that is a through bore. The drill head includes a drive shaft that has an enlarged portion at a downhole end that defines a centroid positioned within the central bore of the drive coupling. The drive shaft includes a drive shaft axis that is misaligned and intersects with an end casing axis of an end casing at a balance point of the drill head. The centroid of the drive shaft is positioned to be coincident with the balance point of the drill head.

A flush of directional drilling apparatus for directionally drilling a lateral bore from a main bore, has a casing in the main bore, the casing having at least one lateral exit port, with a fragmentable plug, flush lateral directional drilling tube, and a pre-installed whipstock guide for guiding the flush lateral directional drilling tube into the lateral exit port to drill a directional lateral hole from the lateral exit port.

A rig control apparatus, system, and method according to which a mud pump is ramped up toward a full-operational pumping pressure to circulate drilling mud via a drill string between a surface location and a downhole tool, the downhole tool being connected to the drill string and positioned within a wellbore, the flow of the drilling mud between the surface location and the downhole tool is stabilized prior to the mud pump reaching the full-operational pumping pressure, data is transmitted via mud-pulse telemetry from the downhole tool to the surface location when the flow of the drilling mud between the surface location and the downhole tool is stabilized, and the mud pumps are ramped up further to the full-operational pumping pressure.