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 threaded tubular connection is provided. The threaded tubular connection includes a pin having external threads, a pin seal surface, and a pin torque shoulder at a free end and a box for receiving the pin, the box having internal threads for interacting with the pin threads, a box seal surface for contacting the pin seal surface and a box torque shoulder for contacting the pin torque shoulder. The pin and box define a longitudinal axis. The pin torque shoulder has a first pin shoulder surface and a second pin shoulder surface, the first pin shoulder surface intersects an axis perpendicular to the longitudinal axis at a first angle and the second pin shoulder surface intersects the perpendicular axis at a second angle. The box torque shoulder has a first box shoulder surface and a second box shoulder surface. The first box shoulder surface intersects an axis perpendicular to the longitudinal axis at a third angle and the second box shoulder surface intersects the perpendicular axis at a fourth angle. A further tubular connection and method are also provided.

A threaded connection includes a first tube having a pin, the pin having pin threads, a circumferential concave outer pin surface, and a pin torque shoulder at a free end, the concave outer pin surface including a pin seal surface and a continuous extension from the pin seal surface to the pin torque shoulder. A second tube has a box, the box has box threads for interacting with the pin threads, a circumferential inner box surface and a box torque shoulder. The inner box surface has a radially inwardly extending box seal surface, the pin seal surface contacts the box seal surface to define a seal. The seal is spaced from the free end when the pin and box torque shoulders contact, the continuous extension continuing from the seal to the pin torque shoulder. A method for making-up a threaded connection is also provided.

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 plug for a pressure test configured for a tubular component, the tubular component including a male threaded element at a free end, the male threaded element including a male thread and a sealing surface, the plug including a thread compatible with the male thread, an inner annular groove, and a sealing ring held in the groove such that the sealing ring is radially compressed between an outer periphery of the male threaded element and a bottom of the inner annular groove.

A pressure balancing apparatus can have a compression collar to mate with a component comprising a seal, and a gripper to anchor to a tube and the compression collar. The compression collar is used to apply an axial force to the tube to relieve shear stress on proximate seals. The method can include mating a compression collar to a component comprising a seal, anchoring a gripper to a tube, mating the gripper to the compression collar, and using the compression collar to apply an axial force to the tube.

A tubular member for threadably engaging another tubular member to form a tubular string includes a first end including a helical female thread formed in an outer surface of the tubular member, wherein the female thread includes a slot extending radially inwards from the outer surface, and a root extending radially inwards from the slot, wherein the root has a maximum width that is greater than a maximum width of the slot, a second end opposite the first end and including a helical male thread formed on an inner surface of the tubular member, wherein the male thread includes a shank extending radially outwards from the inner surface, and a notch extending radially outwards from the shank, wherein the notch has a maximum width that is greater than a maximum width of the shank.

A threaded connection for steel pipe is provided that prevents cross-threading and provides good compression load resistance. A threaded connection (10) includes a pin (30) and a box (40). The male thread stabbing flank (34) of the pin (30) includes two male thread stabbing flank portions (341) and (342). The male thread stabbing flank portion (341) is located farther from the pipe axis (X) of the steel pipe (20) and has a stabbing flank angle (1) of 10 to 15 degrees. The male thread stabbing flank portion (342) is located closer to the pipe axis (X) and has a stabbing flank angle (2) of 20 to 60 degrees. The female thread stabbing flank (44) of the box (40) includes two female thread stabbing flank portions (441) and (442). The female thread stabbing flank portion (441) is located farther from the pipe axis (X) and has a stabbing flank angle (1) equal to the stabbing flank angle (1) of the male thread stabbing flank portion (341). The female thread stabbing flank portion (442) is located closer to the pipe axis (X) and has a stabbing flank angle (2) equal to the stabbing flank angle (2) of the male thread stabbing flank portion (342).

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.

High sealing performance is provided in a threaded connection used for pipes for oil wells with large wall thickness and with a connection efficiency smaller than 1. A threaded connection (10) connects pipes for oil wells (1). The threaded connection (10) includes two pins (11) and a tubular coupling. Each of the pins (11) is provided on an end of the pipe for oil wells (1) and is in continuity with the pipe body (12), which has a wall thickness not smaller than 12 mm. The coupling (2) includes two boxes (21) and a recess portion (22). The box (21) is provided on both ends of the coupling (2). The recess portion (22) has a length not smaller than 10 mm. The threaded connection (10) has a connection efficiency smaller than 1. When the wall thickness of the pipe body (12) is expressed as t.sub.pipe, the wall thickness and length of the recess portion (22) are expressed as t.sub.1 and 2L.sub.1, respectively, and the length of each of the boxes (21) is expressed as L.sub.2, and if the following expressions (1) and (2) define T and L, then, Tand L satisfy the following expression (3):

[00001]$\begin{array}{cc}T=\frac{t_1}{t_{\mathrm{pipe}}}& \left(1\right)\\ L=\frac{L_1}{L_1+L_2}& \left(2\right)\\ T.Math.L^{1/15}>1.4& \left(3\right)\end{array}$