US Patent 10309179 Downhole casing pulling tool

A pulling tool deploys on a workstring to retrieving a well component, such as casing or a liner, stuck downhole. The tool has an anchor, a puller, and an implement. The implement is supported on the end of the puller and engages the component. Hydraulic pressure supplied downhole moves at least one puller piston coupled to the implement along a piston mandrel to pull the implement and component. An anchor mandrel coupled to the workstring and the piston mandrel anchors the pulling tool downhole. The anchor has slips disposed on the anchor mandrel that engage in surrounding casing when an anchor piston disposed on the anchor mandrel is hydraulically actuated with the communicated pressure.