US Patent 9845661 Exercising a well tool

An exercise tool assembly for operating a downhole tool auxiliary to a primary actuator system of the downhole tool includes a cylinder mandrel configured to be received in the central bore of the downhole tool. A piston mandrel is in and sealed with the cylinder mandrel. The exercise tool assembly is configured to couple to an actuator sleeve of the downhole tool and to couple to the downhole tool at a location apart from the actuator sleeve. The piston mandrel is responsive to a change in pressure in the central bore to translate relative to the cylinder mandrel and translate the coupling with the actuator sleeve relative to the coupling at the location apart from the actuator sleeve.