Patent ID: 6264367
Filing Date: 2001-07-24
Classification: E21B

Abstract:
A drill bit for use in an earthen annulus that contains loose particles, the drill bit connected to a fluid supply source, comprising:a bit body having at least one leg, said leg having a journal segment, said bit body further having at least one fluid conduit in fluid communication with the fluid supply source;a roller cone rotatably mounted upon said journal segment, at least one bearing cavity being defined between said cone and said bit body;an annular primary seal disposed between said roller cone and said bit body and between said bearing cavity and the earthen annulus;an annular gap disposed between said roller cone and said bit body and between said annular primary seal and the earthen annulus, said annular gap in fluid communication with said fluid conduit and the earthen annulus;an annular secondary seal disposed between said annular primary seal and the earthen annulus; andat least one partial circumferential groove defined by at least one of said leg and said roller cone between said annular secondary seal and said annular gap and being in fluid communication with said fluid conduit and the earthen annulus, said partial groove circumscribing less than the entire circumference of at least one of said journal segment and said roller cone.