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

A double shoulder threaded tool joint connection includes a pin with external threads formed between a pin external shoulder and a pin internal shoulder, the pin including a nose section between the pin internal shoulder and the pin external thread and a box with internal threads formed between a box external shoulder and a box internal shoulder. The internal threads and the external threads are arranged and designed for connection with each other so that the box and the pin are connected with a common center-line and with a primary seal formed by the pin external shoulder forced against the box external shoulder and a secondary seal formed between the pin internal shoulder forced again the box internal shoulder. The invention may be applied to any threaded joint.

A double shoulder threaded tool joint connection includes a pin with external threads formed between a pin external shoulder and a pin internal shoulder, the pin including a nose section between the pin internal shoulder and the pin external thread and a box with internal threads formed between a box external shoulder and a box internal shoulder. The internal threads and the external threads are arranged and designed for connection with each other so that the box and the pin are connected with a common center-line and with a primary seal formed by the pin external shoulder forced against the box external shoulder and a secondary seal formed between the pin internal shoulder forced again the box internal shoulder. The invention may be applied to any threaded joint.

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.

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 joint for production of tubing includes a male element and female elements, having outer surface and inner surfaces, respectively, whose ends are configured with a trapezoidal tapered thread and with sealing surfaces, auxiliary surfaces and abutting end surfaces, which form an inner sealing assembly. The threads have characteristics described in the present disclosure. Auxiliary surfaces are provided between the sealing surfaces and the abutting end surfaces. The junction between the sealing surfaces and the auxiliary surfaces is configured in the form of a concave spherical surface on the male element and a convex spherical surface on the female element. This provides for the formation of a tight joint under high mechanical loads by virtue of improved coupling characteristics and the prevention of damage to the surfaces.

A threaded joint for production of tubing includes a male element and female elements, having outer surface and inner surfaces, respectively, whose ends are configured with a trapezoidal tapered thread and with sealing surfaces, auxiliary surfaces and abutting end surfaces, which form an inner sealing assembly. The threads have characteristics described in the present disclosure. Auxiliary surfaces are provided between the sealing surfaces and the abutting end surfaces. The junction between the sealing surfaces and the auxiliary surfaces is configured in the form of a concave spherical surface on the male element and a convex spherical surface on the female element. This provides for the formation of a tight joint under high mechanical loads by virtue of improved coupling characteristics and the prevention of damage to the surfaces.

A leak-resistant pipe connection has an annular seal bulge on a pin end of the connection and a tapered seal area adjacent a secondary box shoulder of a box end of the connection. The annular seal bulge is coined on contact with the tapered seal area on initial make-up of the connection which provides a metal-to-metal seal that is very resistant to high-pressure fluid leakage even after the connection is subjected to extreme shear and tensile stresses.

A leak-resistant pipe connection has an annular seal bulge on a pin end of the connection and a tapered seal area adjacent a secondary box shoulder of a box end of the connection. The annular seal bulge is coined on contact with the tapered seal area on initial make-up of the connection which provides a metal-to-metal seal that is very resistant to high-pressure fluid leakage even after the connection is subjected to extreme shear and tensile stresses.

A threaded connection for large diameter steel pipe exhibits high torque resistance and high sealability and, at the same time, provides a shear resistance that suits the size of the steel pipe to be connected. The threaded connection includes a tubular pin provided on a tip of a steel pipe with large diameter, and a tubular box 20 adapted to be drawn up on the pin as the pin is screwed in. The pin includes a male threadform made with a taper thread. The box includes a female threadform made with a taper thread. Each of the threadforms are wedge threads and have a dovetail-shaped cross section. The male threadform is designed such that the width of the thread in an end region of the male threadform closer to the tip is set to a size corresponding to the size of the pipe body of the steel pipe.