Casing hanger running and retrieval tools.

摘要

A tool for setting or retrieving a packoff between the casing hanger and the wellhead utilizes differential area pistons. The tool has a mandrel (27) which connects to a string of drill pipe. The mandrel carries a body (55) and is axially movable relative to the body. A sleeve (75) is carried by the body for connection to the packoff (81). A sleeve piston (89) is carried by the body for relative movement relative to the body. A mandrel piston (97) is carried by the mandrel for movement with the mandrel. Passages (93) in the body communicate the mandrel piston (97) with the sleeve piston (89) and contain an incompressible fluid. Axial movement of the mandrel causes the pressure to increase to drive the sleeve piston downward to set the packoff, or in another embodiment, upward to retrieve the packoff.