| 摘要 |
An expandable threaded connection between segments of expandable tubulars that provides multiple sealing points along the pin and box members that can withstand high pressure is disclosed. The present invention utilizes a gap that is created between the pin nose and the back of the box member when the threaded connection is made up and a reverse trapping angle machined into the pin nose end and the back of the box. The radial expansion of the tubulars causes axial movement of the pin nose and the box member until the pin nose is in contact with the back of the box member, thereby closing the gap and forcing the pin nose into sealing engagement with the back of the box member. The reverse trapping angle forces the nose of the pin member outwardly (i.e., toward the outer diameter of the expandable tubular string) as it is forced into contact with the back of the box member during the expansion process. The force imparted on the pin nose by the reverse trapping angle creates a high pressure radial seal between surfaces of the pin member and the box member. The contact point between the nose of the pin member and the back of the box member creates a high pressure axial seal. By controlling the initial gap size and the reverse trapping angle, the present invention ensures that the axial and radial sealing points are strengthened by the expansion process. The combination of the radial and axial seals created by the expansion process provides an expanded threaded connection that is capable of withstanding high pressure.
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