Debris barrier for packer setting sleeve

摘要

An annular seal for a setting tool in a packer tieback extension comprises a downhole oriented packer cup assembly. As the tool is run in the hole the packer cup flexes as the rising hydrostatic pressure equalizes across the cup into what started as a zone with atmospheric pressure inside the packer tieback extension. Once the pressure is equalized the self energizing feature of the packer cup maintains grit and debris in the mud from entering the tieback extension where the spring loaded dogs of the setting tool are held in a retracted position. If the seal fails to equalize and allows a large differential across the setting sleeve from the surrounding annulus, the rupture disc breaks inwardly into the tieback extension so that pressure is equalized. If the packer is never set after being lowered to depth and the pressure from the tieback extension is equalized into the annulus.

主权项

1. An apparatus for protecting from debris a component of a running tool disposed within a subterranean tool being run for deployment at a subterranean location, comprising:
a running tool mandrel disposed adjacent a component of a subterranean tool to define an annular gap therebetween defining an annular space where components need to be protected from subterranean debris; a self-actuating seal assembly spanning said annular gap for contact with said component during the entire running in from a surface location to the subterranean location except during pressure equalization, said seal assembly comprising a sealing member that allows flow into said annular space as the subterranean tool is run in to equalize initially lower pressure in said annular space with increasing surrounding hydrostatic pressure to reduce differential pressure on the component of the subterranean tool; said annular space, which is closed to flow toward the subterranean location surrounding said mandrel by said seal assembly, is selectively communicated through at least one mandrel wall opening always fully exposed to pressure in said annular space as said seal assembly contacts said component, said opening is covered by a pressure sensitive barrier which is selectively fully opened by defeat of said pressure sensitive barrier automatically responding to differential pressure between pressure at said annular space and the subterranean location surrounding said mandrel at a time when the subterranean tool is run in or pulled out.