A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

An orienting system for precisely aligning downhole tools with respect to each other, such as perforating guns, exploration tools, or other completions tools. The orienting system provides for orienting a first tool with respect to a second tool in a predetermined number of degrees of rotation, and then locking down the combination for use downhole in that configuration.

This invention builds up on technical features and on the industry experience with the use of Merlin™ family connectors. In addition to friction, structural means utilized to transfer high torsional loads include keys and may also include: interlocked thread systems, shear pins, dog-clutch teeth and splines, all used in isolation or in arbitrary combinations. Static and fatigue bending load capacities of the connectors remain high, while the axial load capacities may or may not be high, depending on the design requirements. Connectors according to this invention can be built as new, carefully optimized designs. In some cases upgrading existing Merlin™ family connector designs to increase they torque transfer capacities may be also feasible.

This invention builds up on technical features and on the industry experience with the use of Merlin™ family connectors. In addition to friction, structural means utilized to transfer high torsional loads include keys and may also include: interlocked thread systems, shear pins, dog-clutch teeth and splines, all used in isolation or in arbitrary combinations. Static and fatigue bending load capacities of the connectors remain high, while the axial load capacities may or may not be high, depending on the design requirements. Connectors according to this invention can be built as new, carefully optimized designs. In some cases upgrading existing Merlin™ family connector designs to increase they torque transfer capacities may be also feasible.

A disconnect sub is connected at one end to a pipe for deployment into a well, where the disconnect sub is then connected to a downhole sealing device such as a plug. The disconnect sub comprises a disconnection point that has a lower tensile break value than the rest of the plug, and has a predetermined tensile break value such that the disconnection point will fail when a threshold value of axial tensile load is applied to the disconnect sub. This offers two methods of disconnection of the pipe from the plug after the plug has set—firstly, rotation of the pipe, or if rotation is not possible, overpull of the pipe in excess of the threshold will cause failure of the disconnection point and separation of the pipe from the plug.

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.

A stabilizer can include an outer collar, an inner sleeve, and a locking mechanism. The locking mechanism is changeable between a first mode in which the outer collar is rotationally fixed to the inner sleeve and a second mode in which the outer collar is rotationally isolated relative to the inner sleeve. The stabilizer may include an active or passive system for changing modes. An example passive device may include a magnetic clutch where the detected force overcomes magnetic forces to change mode. The stabilizer can be used to mitigate whirl on a rotating device by switching the rotating device between a rotating mode and a non-rotating mode. In the rotating mode, outer collar may rotate with the inner sleeve. In the non-rotating mode, the outer collar may be rotationally isolated from the inner sleeve.

A stabilizer can include an outer collar, an inner sleeve, and a locking mechanism. The locking mechanism is changeable between a first mode in which the outer collar is rotationally fixed to the inner sleeve and a second mode in which the outer collar is rotationally isolated relative to the inner sleeve. The stabilizer may include an active or passive system for changing modes. An example passive device may include a magnetic clutch where the detected force overcomes magnetic forces to change mode. The stabilizer can be used to mitigate whirl on a rotating device by switching the rotating device between a rotating mode and a non-rotating mode. In the rotating mode, outer collar may rotate with the inner sleeve. In the non-rotating mode, the outer collar may be rotationally isolated from the inner sleeve.

The invention relates to a rod section of a ground drilling rod, wherein the rod section is configured at the end to form a plug connection and has (a) a male connector or (b) a female connector at at least one end, wherein the male connector has at least one circular portion and at least one more straight-line-like portion in cross section on the outside, or the female connector has at least one circular portion and at least one more straight-line-like portion in cross section on the inside.

The invention relates to a rod section of a ground drilling rod, wherein the rod section is configured at the end to form a plug connection and has (a) a male connector or (b) a female connector at at least one end, wherein the male connector has at least one circular portion and at least one more straight-line-like portion in cross section on the outside, or the female connector has at least one circular portion and at least one more straight-line-like portion in cross section on the inside.