Patent Application
20070257486
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function.
“Box member” refers to an end portion of a tubular member or of a coupling employing a female threadform.
“Pin member” refers to an end portion of a tubular member employing a male threadform. The threadable engagement of a pin member within a box member may be referred to as a threaded tubular connection (e.g., threaded connection, a tubular connection, or connection).
“Thread” refers to a ridge of generally uniform section in the form of a helix on the internal or external surface of a tubular member such as a pipe or a coupling.
“Tubular member” refers to a joint of pipe (e.g., a casing joint) or a coupling.
In an embodiment, a radially expandable tubular connection includes a box member and a pin member. The box member and pin member are radially expandable. In addition, the box member has an internal thread and a non-threaded area. The radially expandable tubular connection further includes an elastomeric seal ring carried in a specially-dimensioned groove formed in the non-threaded area of the box member. In an embodiment, the groove dimensions are designed to provide a mechanical means for securing the elastomeric seal ring in the groove during transportation and assembly of the radially expandable tubular connection. The pin member has an external thread for threadably engaging the internal thread of the box member, and a non-threaded external seal surface carried by an elongated pin nose for engaging the elastomeric seal ring in a sealable manner. In embodiments in which the external thread is threadably engaged within the internal thread, radial expansion of the radially expandable tubular connection produces deformation to compress the elastomeric seal ring between the pin member and the box member to seal the annular area between the pin member and the box member. The groove width is less than the elastomeric seal ring cross-sectional diameter in a longitudinal direction, and the groove depth is less than the elastomeric seal ring cross-sectional diameter in a radial direction. Consequently, the elastomeric ring may be securely held in the groove during transportation and assembly of the radially expandable tubular connection and may be compressed upon connection make-up and after expansion, which may provide a seal between the pin and the box members of the radially expandable tubular connection.
In some embodiments, the groove has the shape of a “dove tail” with both groove shoulders inclined to the base of the groove at angles less than 90 degrees. In other embodiments, the groove has the shape of a “half dove tail” with one shoulder inclined to the base of the groove at an angle less than 90 degrees and the other shoulder at about 90 degrees.
The groove dimensions may be designed to provide mechanical means for securing elastomeric seal ring 12 in the groove during transportation and assembly of the connection. In an embodiment, the groove has a shape of a “dove tail,” as illustrated in
In an embodiment as illustrated in
In an embodiment as shown in
It is to be understood that elastomeric seal ring 12 may be employed in various different ways. In addition, elastomeric seal ring 12 may be constructed of a suitable resilient material, such as, but not limited to, an acrylonitrile-butadiene, a fluorocarbon, a carboxylated nitrile, an ethylene acrylate, an ethylene propylene, a fluorosilicone, a hydrogenated nitrile, a perfluoroelastomes, compounds thereof, and/or combinations thereof. Elastomeric seal ring 12 may have different cross-sectional shapes. It is also to be understood that the groove may have varieties of shapes such as rounded corners or curved shoulders and/or curved groove base, provided that groove width 24 or 44 are less than cross-sectional dimension 31 in the longitudinal direction, and groove depth 22 or 42 are less than elastomeric seal ring cross-sectional dimension 33 in the radial direction, providing mechanical means for securing position of elastomeric seal ring 12 in the groove. Elastomeric seal ring 12, positioned in the groove, provides a seal between pin member 62 and box member 65, before and after expansion of radially expandable tubular connection 200.
In embodiments, a form of radially expandable tubular connection 200 may be machined on pipe where a pin connection is machined on one end of the pipe, and a box connection is machined on the other end of the pipe. Other embodiments may also be used such as the pipe being threaded with either a pin or a box on both ends and connected with pin-by-pin or box-by-box couplings. The threads may be machined with or without a taper, or there may be provided two thread steps that are radially separated. Moreover, in some embodiments, the threads may be of the “wedge thread” type, where both the stab and load flank are hooked.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
This application is a non-provisional of U.S. Application Ser. No. 60/797,325 filed on May 3, 2006, which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60797325 | May 2006 | US |
