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.

There is provided a threaded connection for pipe having an excellent galling resistance and an excellent appearance. A threaded connection for pipe according to the present embodiment includes a pin (3) and a box (4). The pin (3) and the box (4) have contact surfaces (34) and (44) that include thread parts (31) and (41), metal seal parts (32) and (42), and shoulder parts (33) and (43), respectively. The threaded connection for pipe includes a ZnNi alloy plating layer (100) on the contact surface (34) or (44) of at least one of the pin (3) and the box (4). The ZnNi alloy plating layer (100) contains Cu. The Cu content of the ZnNi alloy plating layer (100) is 4.5% by mass or less (zero excluded).

This invention provides a threaded connection for pipes or tubes having high over-torque performance, and a method for producing the threaded connection for pipes or tubes. A threaded connection for pipes or tubes according to the present embodiment includes a pin and a box. The pin and the box include a contact surface including a threaded portion and a metal contact portion. The threaded connection for pipes or tubes includes a solid lubricant coating layer on at least one of the contact surfaces of the pin and the box, the solid lubricant coating layer including a resin, a solid lubricant powder, and Cr.sub.2O.sub.3.

Oil well pipe component comprising a threaded portion, at least part whereof is coated with a layer of a corrosion-inhibiting material, that has been applied to at least the part of the threaded portion of the oil well pipe component by means of a method comprising a cataphoresis step from an aqueous bath, said method comprising providing the oil well pipe component comprising a threaded portion; immersing at least part of the threaded portion of the pipe component in a cataphoresis bath comprising water and suspended particles of corrosion-inhibiting material, and provided with an anode and a cathode means, the pipe component being connected to the cathode means; inducing a current through the bath, in order to provide the corrosion-inhibiting material with a positive charge; depositing a layer of the positively charged corrosion-inhibiting material onto the pipe component; and removing the immersed part of the pipe component with the layer of corrosion-inhibiting material from the cataphoresis bath and allowing the corrosion-inhibiting material to set.

The invention concerns an abutment for a tubular component, said abutment being overlaid with a coating comprising a principal layer constituted by an alloy selected from nickel-phosphorus alloys, copper-nickel alloys and nickel-tungsten alloys. The invention also concerns a tubular component comprising said abutment and a method for producing such an abutment.

In a threaded joint for pipes constituted by a pin and a box, each having a contact surface comprising a threaded portion and an unthreaded metal contact portion, the contact surface of the pin has a solid corrosion protective, preferably transparent coating based on a UV-curable resin and the contact surface of the box has a solid lubricating coating having plastic or viscoplastic rheological behavior which is preferably formed by the hot melt technique from a composition comprising a thermoplastic polymer, a wax, a metal soap, a corrosion inhibitor, a water-insoluble liquid resin, and a solid lubricant.

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 method for producing a matrix-containing dry film on a threaded tubular component for drilling or working hydrocarbon wells, by applying a mixture containing a dispersion or an aqueous emulsion of an acrylic copolymer with a solution of an alkaline polysilicate in a liquid state onto a threaded end of the threaded tubular component by spraying at a temperature of from 20 C. to 40 C. thereby obtaining a threaded end coated with a film; drying the threaded end coated with the film; and densifying the film.

A corrosion resistant tube and a corrosion resistant tubing connector and methods for making them are disclosed. The tube comprises a tube section main body which is hollow and cylindrical in shape and having two end portions, each end portion having threads, an internal anti-corrosion coating layer on the inner surface of the tube section, an external anti-corrosion coating layer at each of the end portions, and an end anti-corrosion coating layer at each of the end portions. The internal anti-corrosion coating layer, the external anti-corrosion coating layer, and the end anti-corrosion coating layer are resistant to corrosive elements present in crude oil or natural gas.

A connecting element for a tubular component, the connecting element being overlaid with a coating including a principal layer constituted by a nickel-phosphorus alloy, a tubular component including one or more such connecting elements, and a method for producing such a connecting element.