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 downhole assembly includes a first tubular including a first shoulder and a second tubular including a second shoulder. The assembly further includes a transmission element having a first portion disposed in the first shoulder, the first portion includes an electrically conductive member having a first arc length and a second portion disposed in the second shoulder. The second portion includes a contacting element having a second arc length that is substantially less than the first arc length and further includes an outer insulating carrier that defines a groove. The contacting element is disposed in the groove. When the first tubular is joined to the second tubular, the contacting element contacts the electrically conductive member and the second portion defines at least one region between the electrically conductive member and the second portion in areas of the groove where the contacting element does not contact the electrically conductive member.

A threaded connection for steel pipe that provides high torque performance, high tension performance and high sealability is provided. A threaded connection 1 includes: a tubular pin 10 including a pin shoulder 12, a male thread 11 and a pin seal 13; and a tubular box 20 including a box shoulder 22, a female thread 21 and a box seal 23. The male and female threads 11 and 21 are constituted by wedge threads. The pin seal 13 is provided between the pin shoulder 12 and the male thread 11. The box seal 23 corresponds to the pin seal 13 and is located on the inner peripheral surface of the box 20. When the connection is made up, the pin shoulder 12 is spaced apart from the box shoulder 22. The threaded connection 1 satisfies the following expression, (1):

3%≤(LP−SP)/LP≤7%   (1).

In expression (1), LP is the pitch between loading flanks 111 of the male thread 11, and SP is the pitch between stabbing flanks 112 of the male thread 11.

An oil-well metal pipe according to the present disclosure has a pipe main body including a first end portion and a second end portion. The pipe main body includes a pin formed at the first end portion, and a box formed at the second end portion. The pin includes a pin contact surface including an external thread part, and the box includes a box contact surface including an internal thread part. The oil-well metal pipe according to the present disclosure also includes a resin coating containing a resin, a solid lubricant powder, and copper phthalocyanine on or above at least one of the pin contact surface and the box contact surface.

A disclosed threaded connection for steel pipes includes a pin and a box. The pin includes, in order from a front end of the pin toward a pipe body of the pin, an annular shoulder surface, an annular sealing surface located adjacent to the shoulder surface, and a male thread part. The box includes, in order from a pipe body of the box toward a front end of the box, an annular shoulder surface, an annular sealing surface located adjacent to the shoulder surface, and a female thread part. The pin shoulder surface and the box shoulder surface incline from a plane perpendicular to a pipe axis in a direction of screwing the pin. A diameter of an inner circumferential edge of the pin shoulder surface is smaller than a diameter of an inner circumferential edge of the box shoulder surface.

A method of making-up tubular string components can include inputting to an image processor image data output from at least one camera, the image processor in response detecting positions of a tubular and a mark on another tubular, threading the tubulars with each other while inputting position data from the image processor to a controller, and the controller terminating the threading in response to the position of the mark relative to the position of the first tubular being within a predetermined range. Another method of making-up tubular string components can include, in response to inputting image data to an image processor, the image processor detecting longitudinal positions of two tubulars, threading the tubulars with each other, and a controller terminating the threading in response to the longitudinal position of one tubular relative to the longitudinal position of the other tubular being within a predetermined range.

A coupling assembly includes a coupling, a protective ring and two tubulars, the coupling of generally cylindrical shape with a channel therethrough, the coupling having at least one internal thread and two coupling ends and a pin end of at least one of the two tubulars having an external thread for threaded mating therewith so that the coupling assembly provides a connection between the two tubulars, the protective ring including a ring body for positioning adjacent an interior wall of the coupling between the two ends thereof, the ring body being generally cylindrical and having a ring channel therethrough, the protective ring includes one of a tongue and groove and at least one of the ends of at least one of the two tubulars having the other of a tongue and groove.

A threaded coupling comprising a first end, a second end, a first portion of the threaded coupling defining a first thread profile, a second portion of the threaded coupling defining a second thread profile different from the first thread profile, where at least two threads of the second thread profile proximate to the second end are reduced in height according to an extra machining angle.

A threaded tubular connection includes a tubular female end extending from a main body of a first tubular member, and a tubular male end extending from a main body of a second tubular member, such that the tubular male end includes a first machined inner surface close to the male free end and a second machined inner cylindrical surface above a threaded portion of the male end such that a second inner diameter of the second machined inner cylindrical surface is smaller than a first inner diameter of the first machined inner surface.

A threaded tubular connection which includes a pin member and a mating box member. The pin member has pin threads with stab flanks and load flanks and thread crests and thread roots which are adapted to be made-up with a mating box member having a complimentary thread structure. The threads of the pin member are intentionally made asymmetric to those of the box.