A downhole device delivery and drive transfer system includes a sub which is arranged to attach to a drill string and a tool which is configured to enable it to travel through the drill string and releasably couple to the sub. The sub and the tool are arranged so that when they are releasably coupled to each other torque imparted to the drill string is transferred by the sub to the tool. The tool is arranged to carry one or more devices for performing one or more downhole functions such as core drilling, hole reaming or wedge placement for directional drilling. The system also has a guide mechanism that operates between the sub and the tool to guide the tool to a known rotational orientation relative to the sub as the tool travels into the sub. A fluid control system controls the flow of fluid through the tool through a downhole outlet and a plurality of ports intermediate opposite ends of the tool.

A system for connecting a drill bit and pipe puller to a drill string. The system includes a downhole tool having an internal cavity and a through-hole in its wall. A coupler may be slidingly received in the cavity and connected using one or more fasteners which interconnect a groove in the coupler to the wall of the downhole tool. Fasteners used may be screws or bolts interconnecting the wall of the tool with radial holes in the coupler. Alternatively, bolts may interconnect the wall with a circumferential groove on the coupler. A drill bit may be threaded into the coupler. The coupler allows drill bits and other tools to be connected and disconnected from a downhole tool without unthreading the drill bit.

A drill pipe connecting apparatus has radially extending locking openings to the drilling drive of a rig. An inner tube receives a free end of the drill pipe by the locking opening of the drill pipe. An outer tube at least partially encompasses the inner tube and connects to the drive. The inner tube has, at the drill pipe end, radially extending through-recesses for guiding/allowing passage of locking elements, radially slidingly movable in the through-recesses. External guide elements on the outer tube form control gates for adjusting the radial position of the locking elements between open/locking positions by relative rotation. A connecting device releasably connects the tubes in a rotationally fixed manner; positive-locking elements extend circumferentially around the inner face of the outer tube and on the outer face of the inner tube. These elements enter into positive-locking engagement or reach free-running position, depending upon the longitudinal tube position.

A method of borehole pipe installation begins with unfinished stick pipes brought to the installation site and then machined or cut to form male and female ends. The pipe ends are then locked together to form a flush joint. The lock can be provided via a groove cut into one of the ends for receipt of a lock gasket, which secures and seals the joint when the pipes are pushed together, and prevents the pipes from being pulled apart. Alternatively, to the groove and lock gasket, the ends can be glued and screwed together, with the screws allowing the joined pipes to be pulled through the borehole before the glue is dry. The pipe joint has flush exterior and interior surfaces to minimize borehole clearance and maximize fluid flow through the pipe assembly.

A drill string connect tool comprises a housing having first and second sections. The first section has a first recess, and the second section has a second recess. The tool and the first and sections may be in a connected configuration or a disconnected configuration. The connect tool comprises at least one tension member placeable within, and suitable to transfer tensile forces between, the first and second sections when in the connected configuration. A retaining member can retain the tension member within the first and second recesses. The retaining member is selectively dissolvable by a dissolving fluid, while the remaining components of the tool can withstand the dissolving fluid. When exposed to a dissolving fluid, the retaining member dissolves, allowing the tension member to exit the first and second recesses, thereby actuating the tool to the disconnected configuration.

A method for lifting a first well tubular nested in a second well tubular from contact with the second well tubular includes moving a wellbore intervention tool to a location where the first well tubular is in contact with the second well tubular. The well intervention tool is operated to displace a wall of the first tubular until either (i) the wall of the first tubular contacts the second tubular and separates the first tubular from contact with the second tubular, or (ii) an opening is made in the wall of the first tubular. After the opening is made, an object is displaced from the wall of the first tubular until the object contact the second tubular and lifts the first tubular from the second tubular, wherein a circumferentially continuous annular space is opened between the first well tubular and the second well tubular.

The invention relates to a drill head of a ground drilling device having a drill bit and an attachment which can be fastened to the drill bit, wherein at least one dowel pin is provided for holding the attachment on the drill bit, and the drill bit has one or more receptacles for a dowel pin, wherein the receptacle is enlarged with respect to the radius of the dowel pin.

Pipe coupling: a male portion (13) provided with a series of spaced keys (15); a female portion (14) provided with a series of spaced keyways (16) so the keys are a sliding fit; a fastener including a male portion fitting (17) secured to or formed in the male portion (13) and providing at least one internally screw-threaded bore (17b); a female portion socket attached to or formed in the female portion, said female portion socket (18a) including a central aperture (23) shaped to receive a plug (24), both the female portion socket and the plug being radiused to match the radius of the female portion; a securing bolt (27) dimensioned to fit in a corresponding fixing aperture (26) formed in said plug and engage with said bore (17b); wherein when the at least one fastener is assembled the plug is a circumferential clearance fit in the female portion socket.

A self-retaining shear pin tool and methods for connecting downhole tubulars in a wellbore are disclosed. The self-retaining shear pin tool includes a cap having an inner side and an outer side opposite the inner side, the cap defining a first recess formed in the inner side of the cap, the first recess of the cap having a cylindrical portion and a frustoconical portion extending from the cylindrical portion towards the outer side of the cap, and a shear pin disposed partially in the first recess of the cap and extending out of the first recess of the cap. The shear pin includes a body, a first recess extending inward from a first end of the body, a second recess extending inward from a second end of the body, a first swage, and a second swage die.

A downhole tool including a housing, a movable member movably disposed relative to the housing, a release member extending between the housing and the movable member, a floating nut secured to the shear member and movably received in a recess in the movable member.