Patent ID: 7409988
Filing Date: 2008-08-12
Classification: E21B

Abstract:
1. Non-metallic composite inserts for use in an annular blowout preventer packing element where the packing element includes flexible non-metallic composite body disposed about a longitudinal axis, the flexible non-metallic composite body carrying the non-metallic composite inserts in respective radial planes extending from the center of the packing element and adapted to be compressively displaced inwardly towards the axis upon vertical actuation of the packing element, each of the inserts comprising; upper and lower flanges; a web element extending between said flanges, said web element including leading and wailing edges each having outer arcuate surfaces that are substantially semicircular far distributing loads applied to a bond line between the inserts and the flexible non-metallic composite body during the operation of the packing element, and a central rib extending between the edges, the rib being thinner than the edges, whereby said web element exhibits a substantially dumbbell-shaped cross section for efficient reinforcement of the flexible non-metallic composite body, whereby, because the inserts are non-metallic, sparks are inhibited between the inserts and a drill string in a borehole in which the packing element is mounted, the need to remove the drill string from the borehole due to the packing element is reduced, and wear is reduced.