摘要 |
A motor driven hydraulic lift pump assembly for oil wells includes a mechanical flywheel connected to a hydraulic pump/motor combination in turn incorporated in the hydraulic circuit of the well lift cylinder. The pump/motor and flywheel assembly with associated hydraulic control can be separately mounted on a skid and connected into the hydraulic and electrical circuitry for the well lift cylinder. The combination pump/motor reverses in mode as the vertically mounted well cylinder piston moves upwardly and downwardly to pump from a deep well. As the well cylinder piston moves downwardly the pump/motor is in motor mode storing energy by increasing the rotational speed of the flywheel. As the well cylinder piston moves upwardly the pump/motor is in the pump mode and energy is taken from the flywheel to assist in raising the well cylinder piston to pump crude oil from the deep well. Thus, a portion of the energy released as the well cylinder piston moves downwardly on the return stroke is saved in the flywheel and recycled to assist in raising the well cylinder on the pumping stroke.
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