Collapsing type seal for expandable tubular connections

Abstract

A seal for a radially expansible conduit connection is disclosed. The seal includes a first sealing surface disposed proximal to an end of a male portion of the connection and a corresponding second sealing surface disposed proximal to an end of a female portion of the connection. The first and said second sealing surfaces are substantially opposite each other upon connection of the male and female portions. The seal includes a first clearance surface proximal to the first sealing surface and a second clearance surface proximal to the second sealing surface. The first and second clearance surfaces are substantially opposite each other upon connection of the male and female portions. The first and second clearance surfaces, and the first and second sealing surfaces each have a diameter such that upon radial expansion of the male portion and the female portion after coupling together thereof, the clearance surfaces remain out of contact while the sealing a surfaces contact each other so as to develop a contact pressure. In one embodiment, the clearance between the sealing surfaces prior to expansion is about 30 to 40 percent of the amount of expansion. In another embodiment, the sealing surfaces are in interference contact prior to expansion. In one embodiment, the clearance surfaces have a clearance, prior expansion, of about 50 to 55 percent of the amount of expansion. In a particular embodiment, the conduit connection is a threaded coupling.

Dependencies are inferred from the claim text.