A non-frustoconical coupling provides a mechanical connection used in fluid transport for hydrocarbon recovery operations.

Aspects of the disclosure describe a non-frustoconical coupling used in connections for tubulars in hydrocarbon recovery operations.

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 shear pins and may also include: interlocked thread systems, dog-clutch teeth, keys 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.

An alignment sub may include a first sub body part rotatably coupled to a second sub body part. The first sub body part and second sub body part may be respectively non-rotatably coupled to a first wellbore tool and a second wellbore tool. A lock screw switchable between an unlocked state and a locked state may fix an angular position of the first sub body part relative to an angular position of the second sub body part when the lock screw is in the locked state.

The present disclosure provides a portable seafloor drill rig for a submersible for multi-point core drilling, including a power head, a reduction gear box, an emergency jettison device, a drilling tool, and a temperature and pressure-retaining device. a water supply connector and the power head are arrange on a top plate of the reduction gear box. An output shaft of the power head is connected to an input shaft of the reduction gear box, and an output shaft of the reduction gear box is provided with a central hole, which is in communication with a water inlet hole of the water supply connector. An output shaft of the reduction gear box is connected to the emergency jettison device, and the temperature and pressure-retaining device can perform temperature and pressure-retaining storage of the core drilled by the drilling tool.

The invention relates to a tubular threaded joint for use in the oil and gas industry. A tubular threaded joint comprising a first tubular member (1) having a pin (100) and a second tubular member (2) having a box (200), wherein the pin is an end portion of the first tubular member and comprises on its radially outward-facing surface a male threaded zone comprising a tapered male thread (150). The box is an end portion of the second tubular member and comprises on its radially inward-facing surface a female threaded zone comprising a tapered female thread (250). The male thread and female thread are configured to engage with each other when the joint is in a made-up state. The male thread and female thread are each trapezoidal and comprise a crest, a root, a load flank, and a stabbing flank. On both of the male thread and the female thread at least one of the load flank and the stabbing flank is negatively inclined. A first portion of the male thread extending from an end thereof has a first taper relative to a longitudinal axis of the first member. A first portion of the female thread extending from an end thereof has a second taper relative to a longitudinal axis of the second member, the first portion of the male thread and the first portion of the female thread are configured to engage with each other when the joint is in the made-up state. The second taper is different from the first taper such that the threads converge toward an end of the threads in the made-up state.

A threaded connection for steel pipe is provided in which galling does not easily occur on any of the inner and outer threads. A threaded connection for steel pipe 1 includes a pin 10 and a box 20. The pin 10 includes: a nose 12; a tapered inner male thread 14; a tapered outer male thread 17; a pin inner sealing surface 13; a pin intermediate shoulder surface 18; and a pin intermediate sealing surface 16. The box 20 includes: a tapered inner female thread 24; a tapered outer female thread 27; a box inner sealing surface 23; a box intermediate shoulder surface 28; and a box intermediate sealing surface 26. Each of the inner male thread 14, outer male thread 17, inner female thread 24 and outer female thread 27 includes a perfect thread portion 141, 171, 241, 271. Each perfect thread portion includes an inner end located relatively close to the tip of the pin 10 and an outer end located relatively close to the end of the pin 10 opposite to its tip. The threaded connection for steel pipe 1 satisfies the following Expressions (1) and (2):

x.sub.1+L.sub.1<X.sub.2  (1), and

u.sub.1+L.sub.2<U.sub.2  (2).

A threaded tubular connection for drilling or operating hydrocarbon wells comprising a longitudinal axis, a metal pin member having a tapered two-step wedge pin thread with dovetail wedge threads and a pin sealing surface located between the small and large diameter pin thread steps, and a metal box member having a tapered two-step wedge box thread with dovetail wedge threads and a box sealing surface located between the small and large diameter box thread steps, wherein the tubular connection is free from any final make-up stop shoulder defining a final make-up position for the pin member relative to the box member, the small diameter wedge thread set and the large diameter wedge thread set are dimensioned to have a first axial clearance and a second axial clearance.

A mechanical connector, including a telescopically assembled, Merlin™ Family Connector is provided with one or more sets of threads on substantially matching frustoconical surfaces of a pin and a box of the connector. Strengthening means are introduced involving at least one of: a mechanical stiffening arrangement on an outside surface of the box or a mechanical stiffening arrangement on an inside surface of the pin. The strengthening means provided may involve systems of arbitrarily oriented ribs and/or fairing surfaces. The mechanical stiffening arrangements may be integral with the box or the pin, or they can be separate external/internal strengthening arrangements, as applicable. They can be also essentially annular clamps that would have relatively regular shapes essentially conforming to the external or internal surfaces of the box or the pin, respectively. The above modifications can be introduced to traditional connectors and to connectors designed to transfer high torsional loads.

A system for making a connection between a first tubular member and a second tubular member having coincident bores for conveying a fluid, the connection having an axis in the general direction of flow of said fluid therethrough, the system comprising a connection (1) and a tensioning tool (100), the connection having a first tubular end (6) comprising a first end flange (16) having an end face (17) and a collar (20) comprising a sleeve (21) and an end stop (30) fixed to the sleeve (21), said sleeve (21) arranged about said flange (18) and said end stop (30) arranged about said tubular end (6), said collar (20) slideable along said tubular end (6), the connection further having a second tubular end (7) comprising a second end flange (43) having an end face (45) and a locking nut (50) about and slideable along said first tubular end (7), the tensioning tool (100) for applying axial tension to said collar (30) relative to said second tubular end (7) characterised in that at least one of said sleeve (20) and said second tubular end (7) has a set of parallel circumferential grooves (23,47) therein and said tensioning tool (100) has a set of ridges (142), the system comprising the steps of moving said set of ridges (142) into said set of grooves (23,47) and applying an axial tension to said collar (20) relative to said second tubular end (7).