Abstract: Connectors and connections that enhance mechanical and sealing engagement between the ends of tubular bodies that are radially expanded by a forging tool. The connectors are designed to maintain or restore mechanical and sealing engagement following expansion. The connections are made by joining components that exhibit different spring back characteristics following mechanical deformation. Dissimilar material may be used for the connectors or the connected components can be made of the same materials but dimensioned and configured to exert an interfering force between engaged components following expansion. In operation, a material or component with a high spring back characteristic is positioned adjacent a material or component having a lower spring back characteristic. Following passage of a forging tool, the expanded components spring back differently toward their original unexpanded dimensions to produce the enhanced seal or mechanical engagement.

Abstract: A coupled version of a threaded connection 10 includes first threads 16, 38 and second threads, 20, 34 on both elongate tubulars 14, 30 and a coupling 45. An integral joint version 50 preferably includes a first and second tapered threads 58, 60 on each of the connected tubular bodies 54, 56. The coupling preferably includes a dope entrapment cavity in one of the connected tubulars between the first and second threads. A tapered metal seal surface is provided preferably between the first and second threads. The second thread in a preferred embodiment is a hook thread with a negative rake angle. In another embodiment, the pin ends of a coupled connection may engage, with seals provided between the first and second threads on each tubular.

Abstract: Connectors and connections that enhance mechanical and sealing engagement between the ends of tubular bodies that are radially expanded by a forging tool. The connectors are designed to maintain or restore mechanical and sealing engagement following expansion. The connections are made by joining components that exhibit different spring back characteristics following mechanical deformation. Dissimilar material may be used for the connectors or the connected components can be made of the same materials but dimensioned and configured to exert an interfering force between engaged components following expansion. In operation, a material or component with a high spring back characteristic is positioned adjacent a material or component having a lower spring back characteristic. Following passage of a forging tool, the expanded components spring back differently toward their original unexpanded dimensions to produce the enhanced seal or mechanical engagement.

Abstract: A coupled version of a threaded connection 10 includes first threads 16, 38 and second threads, 20, 34 on both elongate tubulars 14, 30 and a coupling 45. An integral joint version 50 preferably includes a first and second tapered threads 58, 60 on each of the connected tubular bodies 54, 56. The coupling preferably includes a dope entrapment cavity in one of the connected tubulars between the first and second threads. A tapered metal seal surface is provided preferably between the first and second threads. The second thread in a preferred embodiment is a hook thread with a negative rake angle. In another embodiment, the pin ends of a coupled connection may engage, with seals provided between the first and second threads on each tubular.

Abstract: Threaded and coupled pipe connections are provided with a number of design features that increase resistance of the connection to fatigue failure from cyclical side loading. The features acting alone or in combination include the provision of a pin thread that is formed along a single taper and that vanishes at the surface of the pipe. The coupling engages the pin such that the threaded area of the coupling engages all of the pin threads and extends beyond the vanish point of the pin threads at the optimum coupling makeup position. The threads of the coupling and pipe may engage along both the stab and load flanks to distribute the side loading. The external surface of the coupling may be tapered from the center toward each coupling end to reduce the stiffness ratio of the connection, and the ends or faces of the coupling may be reduced in radial thickness to prevent coupling splitting.

Abstract: A threaded connection for tubular members comprising a box connector having axially spaced threaded sections and a thread-free section therebetween, the threaded sections of the box connector defining a two-step thread, a pin connector having axially spaced threaded sections and a thread-free section therebetween, the threads in the box connector mating with the threads on the pin connector, there being at least one annular relief in the thread-free portion of at least one of the pin connector and the box connector, an axially facing pin torque shoulder being formed on the pin connector and an axially facing box torque shoulder being formed on the box connector, a metal-to-metal seal being formed between the thread-free sections of the pin and box connectors when the pin torque shoulder and the box torque shoulder are engaged, the annular relief being adjacent the metal-to-metal seal.

Abstract: A threaded connection for tubular members comprising a box connector having axially spaced threaded sections and a thread-free section therebetween, the threaded sections of the box connector defining a two-step thread, a pin connector having axially spaced threaded sections and a thread-free section therebetween, the threads in the box connector mating with the threads on the pin connector, there being at least one annular relief in the thread-free portion of at least one of the pin connector and the box connector, an axially facing pin torque shoulder being formed on the pin connector and an axially facing box torque shoulder being formed on the box connector, a metal-to-metal seal being formed between the thread-free sections of the pin and box connectors when the pin torque shoulder and the box torque shoulder are engaged, the annular relief being adjacent the metal-to-metal seal.

Abstract: Methods and apparatus are provided for obtaining a secure mechanical connection and a pressure-tight seal in the overlapping area of two telescoping tubular bodies. The two bodies, including the overlapping area, are radially expanded to increase the inside diameter of the bodies. The expansion forces an annular seal in the overlapping area into a pressure-sealing engagement between the bodies. A string of pipe assembled from joints secured to each other by telescoping, threadedly engaged expanded pin and box connections may be radially expanded into a surrounding well bore to provide a cased well having an internal diameter greater than the original internal diameter of the pipe string. The seal in the connection comprises an annular elastomeric seal ring and an annular Teflon spacer ring carried in a specially dimensioned groove formed in either the box or the pin, or both members of the connection.