Patent ID: 6044908
Filing Date: 2000-04-04
Classification: E21B

Abstract:
In a sliding sleeve valve for controlling fluid flow between a well annulus and a string of well conduit, said valve including a tubular housing adapted for connection into said string and having at least one radial flow port therethrough, a sleeve disposed co-axially within said housing for selective, longitudinal movement relative to said housing, said sleeve having an annular outer seal portion and at least one radial flow aperture, a primary annular seal member carried by said housing, disposed between and sealingly engaging said housing and said seal portion of said sleeve and spaced longitudinally from said flow port in a first direction, said valve having a closed position wherein said sleeve is positioned such that said flow aperture is axially spaced from said primary seal member in said first direction and an open position wherein said flow aperture is longitudinally spaced from said primary seal member in a second direction opposite the first direction and in communication with said flow port, the improvement characterized in that said primary seal member, in a relaxed condition, comprises an annular, monolithic body having a first, radially outwardly facing, annularly extending, seal surface and a second, radially inwardly facing, annular extending seal surface, said second seal surface comprising first and second, axially spaced, annularly extending, radially inwardly projecting ribs, each of said ribs having a radially innermost convex portion when viewed in transverse cross-section, an annularly extending relief being formed being formed between said first and second ribs, said first seal surface sealingly engaging said housing and said convex portion sealingly engaging with said seal portion of said sleeve when said primary seal member is disposed between said housing and said sleeve, said seal member being made of a substantially non-elastomeric material but having sufficient memory to provide an interference seal between said seal member and said housing, and said seal member and said sleeve.