A lifting plug is for lifting a tubular column in a gas and/or oil well. The lifting plug is a one-piece component capable of being manipulated by a jaw of an oil platform elevator. The plug includes a body to be screwed onto the tubular column. The body includes two outer flanges: an upper flange and an intermediate flange. The flanges are such that the jaw of the elevator can be arranged between these two flanges. The upper flange forms a bearing shoulder for the jaw to bear on and the intermediate flange includes a bore for manipulating the plug allowing the insertion through the body of a pin emerging at two different points of the intermediate collar. The plug can be rotated by the pin while remaining engaged in the jaw.

A retention system for attaching a collar to a pipe. The collar has an internally-disposed groove configured for placement of a ring. The ring is sized such that in one orientation, it can enter the collar between torque-transmitting features into the internally-disposed groove. Once in the groove, the ring may be adjusted such that its aperture is generally aligned with the axis of the collar. In this orientation, the features retain the ring within the groove. A bolt and a pipe may then be placed within the collar from opposite sides. The bolt is attached to the pipe through the ring. Once joined, the collar is joined to the pipe, forming its box end. Such a retention system may be used to join a series of inner pipe members of a dual-member pipe assembly, as in horizontal directional drilling.

A threaded connection includes a pin and a box. The pin includes, in the order from a free end side of the pin toward a tubular body side thereof, an inner sealing surface, an inner male threaded portion, a shoulder portion, an outer male threaded portion, and an outer sealing surface. The box includes, in the order from a tubular body side of the box toward a free end side thereof, an inner sealing surface, an inner female threaded portion, a shoulder portion, an outer female threaded portion, and an outer sealing surface. Between the inner sealing surface and the inner female threaded portion of the box, an inner groove along a circumferential direction is provided, and some threads of the inner male threaded portion of the pin are contained in the inner groove.

A coupling for connecting downhole tubulars includes a tubular body, and at least one thread of a male screw thread formed on an outer surface of the body, and a female screw thread formed in an inner surface of the body. The at least one thread has a thread-form including a crest, a root, and a pair of flanks. The crest and the root are each cambered about a respective first and second camber radius. Each camber radius is greater than an outer diameter of the coupling.

A retention system for attaching a collar to a pipe. The collar has an internally-disposed groove configured for placement of a ring. The ring is sized such that in one orientation, it can enter the collar between torque-transmitting features into the internally-disposed groove. Once in the groove, the ring may be adjusted such that its aperture is generally aligned with the axis of the collar. In this orientation, the features retain the ring within the groove. A bolt and a pipe may then be placed within the collar from opposite sides. The bolt is attached to the pipe through the ring. Once joined, the collar is joined to the pipe, forming its box end. Such a retention system may be used to join a series of inner pipe members of a dual-member pipe assembly, as in horizontal directional drilling.

A drill string including an elongate hollow main length section and a male spigot portion provided at the second end and having an externally threaded section and a non-threaded shank positioned axially intermediate the main length section and the threaded section. The shank includes a transition section positioned adjacent the main length section or a radially projecting shoulder at the second end. The transition section has an outside diameter that increases in a direction from the male spigot portion to the main length section or the shoulder. The cross-sectional shape profile of the outer surface of the transition section in the plane of the longitudinal axis has a segment of an ellipse having semi-major axis (a) and a semi-minor axis (b), wherein the ratio of the semi-major to semi-minor axes (a:b) is within the range 2b<a<8b.

A gap sub assembly for electromagnetic telemetry used in downhole drilling. The gap sub comprises a female part comprising a female mating section and a male part comprising a male mating section. The male mating section is matingly received within the female mating section and electrically isolated therefrom. One or more electrically insulating bodies secure the male part axially and torsionally relative to the female part. The electrically insulating bodies also electrically isolate the male part from the female part. The electrically insulating bodies can be installed through apertures in the female part or at least some of the electrically insulating bodies can be installed before the male mating section is inserted into the female mating section. The electrically insulating bodies can be held in place on the male mating section using a retention apparatus such as a ring, a scarf, pods or an adhesive.

A pipe connection includes a pin having circumferentially extending external grooves. A box has an annular base with deflectable fingers extending upward from the base. Each of the fingers has circumferentially extending internal grooves on an inner side and an external thread on an outer side. A collar has an internal thread on an inner side. A radial dimension from the axis to the internal thread crest decreases from turn to turn of the internal thread in a downward direction. The box and the pin are movable from a stab-in position to a locked position in response to rotation of the collar. In the locked position, the external thread crests are in engagement with the internal thread crests, and the internal grooves are in full engagement with the external grooves.

A tubular string comprises a plurality of torque connectors connecting a plurality of tubular members. At least one torque connector of the plurality of torque connectors comprises a pin component threadably connected to the box component. The pin comprises a three torque shoulders corresponding to three surfaces of the box component. In at least one embodiment, a sacrificial material is deposited between one of the torque shoulders and one of the surfaces to provide additional torque capacity to the torque connector. Additional apparatus, methods, and systems are disclosed.

A drill string rod and a drill string assembly includes a drill rod and a drill bit. The rod includes a threaded male end and a female end. An axially extending shoulder is provided at the male end and has an axial length greater than an outside diameter of the shoulder to provide a shoulder driven rod exhibiting enhanced guidance to achieve straighter holes and better collaring.