PACKOFF NIPPLE

摘要

A packoff nipple is provided for sealing an annular space in a well pipe. The packoff nipple generally comprises a tubular body and a sealing assembly positioned around the tubular body and axially moveably thereon. A stop restrains the sealing assembly from extruding in to the annular space. The sealing assembly includes one or more elastomeric sealing rings having a circumferential groove formed in a downhole face. An axially moveable actuator, preferably a packer cup, engages the sealing ring assembly to causes at least an expansion portion of the sealing rings to expand radially outwardly to seal the annular space and the sealing ring assembly to contact the uphole stop. The sealing rings are axially compressed between the uphole stop and the actuator to further expand the sealing rings. Preferably the uphole stop is concave to urge the sealing rings away from the well pipe and thus further avoid extrusion. As the sealing rings are not extruded past the uphole stop or otherwise permanently deformed, the packoff nipple is reusable and thereby cost- effective.