Patent ID: 10774829

Abstract:
A hydraulic lift apparatus for operating a downhole pump features a hydraulic linear actuator with a piston longitudinally slidable on a central axis of a rotatable portion of a housing. An anti-rotation rod runs longitudinally through the piston at a position radially offset outwardly from the central axis to prevent rotation between the piston and housing. A stationary motor powers a drive train whose output is connected to the rotatable portion of the housing and centered on the central axis. The actuator is one-way actuator with a hydraulically driven upstroke. A leak detection passage extends through the piston to collect fluid that has leaked across the piston seals and convey it to a leak detection port and associated containment tank. A position sensor for monitoring the piston movement features a sensing rod depending downwardly into a hollow piston shaft carried by the piston and connected to the pump rod.