Abstract: A threaded joint for joining tubes used especially in the field of OCTG (Oil Country Tubular Goods), such as pipes in gas or oil production and/or casings when drilling wells can include a pin and a coupling, or box, having an end surface not facing against any surface of the pin when the joint is made-up. Following make-up of the joint, first sealing surfaces of the pin and box mate to form an internal metal-to-metal seal, and second sealing surfaces of the pin and box mate to form an external metal-to-metal seal, where the internal and external seals are defined by contact between one toroidal surface and one frusto-conical surface.

Abstract: A threaded joint comprises a seal ring positioned between a pin and a box, and located in a groove between the end of a threaded section and the nose of the box. The seal ring has a first base, a second base axially opposite to the first base, at least two protruding annular ribs on the external surface, and an internal surface comprising, in an unloaded position, two frustoconical annular surfaces tapering towards the center of the seal ring and joined by a fillet.

Abstract: A threaded joint has a sealing ring radially positioned between a pin and a box and axially positioned on a portion of the pin on an opposite side of the threads of the pin from the nose of the pin. The sealing ring has two protruding annular lips positioned at a skewed angle to the longitudinal axis, two or more radial annular ribs on an external surface, an internal surface, and an at least partly embedded reinforcement ring. When the joint is made up, the sealing ring is in sealing contact with an annular groove of the box by the annular ribs and in sealing contact with the pin by the internal surface. The internal surface of the sealing ring can have a uniform diameter or have radially protruding annular ribs.

Abstract: A make-up method for a threaded joint with a pin and a box to increase the fatigue life of the joint is provided. The method includes the step of applying a torque for making up the pin in the box until first and second abutment shoulders of the pin and the box abut. The method can also include the step of applying an additional torque to the threaded joint until a magnitude of between 50% and 90% of the yield strength of the joint material in the most stressed part of the joint is reached.

Abstract: A threaded joint comprises a pin coupled to a box with an annular groove, one or a pair of seal rings, and hydraulic actuating means to pressurize the seal ring or rings against the pin to provide sealability of the joint. The seal ring or rings comprise a frustoconical surface, an external surface, and an internal surface with one or more protruding annular ribs. In the unpressurized state, the seal ring or rings do not protrude from the groove. In the pressurized state, the frustoconical surface of the sealing ring is in sealing contact with an internal surface of the annular groove of the box, and the annular ribs of the sealing ring are in sealing contact with the external surface of the pin.

Abstract: A threaded joint includes a first seal ring having a tapered shape in a cross section on an axial plane, this ring having an L-shaped metal reinforcement ring embedded in it. The threaded joint can also include a second seal ring positioned more internal to the first seal ring and located in a housing between the end of a threaded section and the nose of the box. The second seal ring has a first base, a second base axially opposite to the first base, and protruding annular ribs either on the external surface or on an internal surface.

Abstract: A threaded joint has an interference between thread roots of the pin and thread crests of the box of between 1% and 5% of the average thickness of the connection, and a root to load flank radius R in the range of 0.2 mm and 0.4 mm. In other embodiments the interference can be between thread roots of the box and thread crests of the pin. The threaded joint can also have a surface treatment that includes shot peening applied to the beginning and end of the threaded zone of the pin.

Abstract: A threaded joint for joining tubes used especially in the field of OCTG (Oil Country Tubular Goods), such as pipes in gas or oil production and/or casings when drilling wells can include a pin and a coupling, or box, having an end surface not facing against any surface of the pin when the joint is made-up. The pin can have a pin threaded portion between a first sealing surface distal of the pin threaded portion and a second sealing surface proximate to the pin threaded portion. The coupling or box can have a box threaded surface between a first sealing surface and an abutment shoulder located proximate to the box threaded surface and a second sealing surface distal of the box threaded surface.

Abstract: A threaded joint has an interference between thread roots of pin and thread crests of the box of value comprised between 1% and 5% of the average thickness of the connection, and a root to load flank radius R comprised in the range of 0.2 mm and 0.4 mm and a surface treatment comprising shot peening applied to the beginning and end of the threaded zone of the pin. In other embodiments the interference can be between thread roots of box and thread crests of the pin.

Abstract: A make-up method for a threaded joint with a pin and a box to increase the fatigue life of the joint is provided. The method includes the step of applying a torque for making up the pin in the box until first and second abutment shoulders of the pin and the box abut. The method can also include the step of applying an additional torque to the threaded joint until a magnitude of between 50% and 90% of the yield strength of the joint material in the most stressed part of the joint is reached.

Abstract: A threaded joint (1) comprises a first seal ring (30) having a tapered shape in a cross section on an axial plane, this ring having an L-shaped metal reinforcement ring (34) embedded in it, and/a second seal ring (6) positioned more internal to the first seal ring (30) and located in a housing (18) between the end of a threaded section (5) and the nose (15) of the box. The second seal ring (6) has a first base, a second base axially opposite to the first base, and protruding annular ribs either on the external surface or on an internal surface.

Abstract: A threaded joint comprises a pin coupled to a box with an annular groove, one or a pair of seal rings, and hydraulic actuating means to pressurize the seal ring or rings against the pin to provide improved scalability of the joint. The seal ring or rings comprise a frustoconical surface, an external surface, and an internal surface with one or more protruding annular ribs. In the unpressurized state, the seal ring or rings do not protrude from the groove. In the pressurized state, the frustoconical surface of the sealing ring is in sealing contact with an internal surface of the annular groove of the box, and the annular ribs of the sealing ring are in sealing contact with the external surface of the pin.

Abstract: A threaded joint has a sealing ring radially positioned between a pin and a box and axially positioned on a portion of the pin on an opposite side of the threads of the pin from the nose of the pin. The sealing ring has two protruding annular lips positioned at a skewed angle to the longitudinal axis, two or more radial annular ribs on an external surface, an internal surface, and an at least partly embedded reinforcement ring. When the joint is made up, the sealing ring is in sealing contact with an annular groove of the box by the annular ribs and in sealing contact with the pin by the internal surface. The internal surface of the sealing ring can have a uniform diameter or have radially protruding annular ribs.

Abstract: A threaded joint comprises a seal ring positioned between a pin and a box, and located in a groove between the end of a threaded section and the nose of the box. The seal ring has a first base, a second base axially opposite to the first base, at least two protruding annular ribs on the external surface, and an internal surface comprising, in an unloaded position, two frustoconical annular surfaces tapering towards the center of the seal ring and joined by a fillet.

Abstract: A radially expandable sealed tubular joint for use in oil and gas wells having a pair of radially expandable tubular elements each having threading at a free end thereof and coupled to one another to form a flush joint connection, the threading including hooked incomplete threads located at least adjacent the free ends, and a sealing substance extending between and adhering to the threading of one element and the threading of the other element, wherein after a radial expansion of the coupled pair of elements the sealing substance remains extended between and adhered to the threading of one element and the threading of the other element. The sealing substance is either a greaseless elastomeric sealant coated on one or both of the pair of elements or a pure metal applied to each of the pair of elements.