Well service tool

摘要

A well service tool has a mandrel including a fluid flow conduit therethrough in fluid communication with a workstring including a fluid pressure source. An expendable knife-mounting sleeve is coupled to the mandrel and includes at least one cutting knife pivotally secured thereto. A housing is disposed about and secured against rotation relative to the mandrel by drive pins and is selectively movable relative to the mandrel responsive to fluid pressure from the fluid pressure source. The housing includes a positive extender to extend the cutting knives and temporarily maintain them in an extended position. A closure member is coupled to the mandrel to selectively obstruct fluid flow through the fluid conduit, wherein fluid pressure within the fluid conduit is increased, and wherein relative movement between the housing and the mandrel is induced. A probe is coupled to the housing to open the closure member upon a selected extension of the cutting knives wherein fluid pressure within the mandrel is decreased. At least one stabilizer may be coupled between the mandrel and the housing and is extendable from the housing to center the well service tool in the wellbore and to provide reversed relative movement between the housing and the mandrel to retract the knife from the extended position.