Bi-directional seal assembly

摘要

A bi-directional seal assembly for sealing the annulus between an inner tubular member and an outer tubular member comprises an annular seal which in cross section includes a generally U-shaped first portion having a radially inner first leg and a radially outer second leg and a generally U-shaped second portion having a radially inner third leg and a radially outer fourth leg. The second and third legs are joined together such that the first leg engages the inner tubular member and the fourth leg engages the outer tubular member. Pressure below the seal urges the first leg into sealing engagement with the inner tubular member and forces the second and third legs radially outwardly to thereby urge the fourth leg into sealing engagement with the outer tubular member. Also, pressure above the seal urges the fourth leg into sealing engagement with the outer tubular member and forces the second and third legs radially inwardly to thereby urge the first leg into sealing engagement with the inner tubular member.

主权项

1. A seal assembly for sealing an annulus between an inner tubular member and an outer tubular member, the seal assembly comprising:
an annular first seal which sealingly divides the annulus into a first part located below the first seal and a second part located above the seal and which in cross section includes:
a generally U-shaped first portion which comprises a radially inner first leg and a radially outer second leg, the first and second legs defining a first cavity;a generally U-shaped second portion which is located radially outwardly of the first portion and which comprises a radially inner third leg and a radially outer fourth leg, the third and fourth legs defining a second cavity;wherein the second and third legs are joined together between the first and fourth legs such that the first cavity faces one of the first and second parts of the annulus and the second cavity faces the other of the first and second arts of the annulus; and wherein the first seal is part of a packoff which also includes a lower packoff body which is located in the first part of the annulus and an upper packoff body which is located in the second part of the annulus; an annular second seal which is positioned between the first seal and the lower packoff body and which in cross section comprises:
a generally U-shaped third portion which comprises a radial inner fifth leg a radial outer sixth leg, the fifth and sixth legs defining a third cavity;a generally U-shaped fourth portion which is located radially outwardly of the first portion and which comprises a radially inner seventh leg and a radially outer eighth leg, the seventh and eight less defining a fourth cavity;wherein the sixth and seventh legs are joined together between the fifth and eight legs; wherein the first and second seals are oriented such that the first and third cavities face in opposite directions and the second and fourth cavities face each other.