Patent ID: 8523533

Claim:
A hydraulic pumping unit for removing well fluids from a well, comprising: a drive motor having a rotary shaft for turning in a first angular direction; a reservoir for a hydraulic fluid; an accumulator for storing potential energy in response to receiving the hydraulic fluid; a sucker rod assembly disposed in the well for removing the well fluids from the well; a ram connected to said sucker rod assembly for moving in an up-stroke from a retracted position to an extended position and moving said sucker rod assembly from a lowered position to a raised position, and moving in a down-stroke from said extended position to said retracted position with said sucker rod assembly moving from said raised position to said lowered position; a ram pump connected to said rotary drive shaft, said ram pump having a ram pump suction port connected to said reservoir and a ram pump discharge port connected to said ram for during the up-stroke of said ram transferring the hydraulic fluid into said ram and moving said ram from said retracted position to said extended position, and during the down-stroke transferring the hydraulic fluid into said reservoir; an accumulator pump connected to said rotary drive shaft, said accumulator pump having an accumulator pump suction port connected to said reservoir and an accumulator pump discharge port connected to said hydraulic accumulator for transferring the hydraulic fluid into said hydraulic accumulator and storing potential energy in said hydraulic accumulator during the down-stroke of said ram, and during the up-stroke transferring the hydraulic fluid into said reservoir; at least one control unit adapted for controlling flow rates of the hydraulic fluid through said ram pump and said accumulator pump, and adapting said ram pump for pumping the hydraulic fluid into said ram during the up-stroke and during the down-stroke passing the hydraulic from said ram into said reservoir and turning said rotary shaft in said first angular direction to power said accumulator pump in response to pressures within the ram provided by the weight of said sucker rod assembly in combination with said drive motor, and adapting said accumulator pump for pumping the hydraulic fluid into said accumulator during the down-stroke and during the up-stroke passing the hydraulic fluid from said accumulator into said reservoir and turning said rotary shaft in said first angular direction to power said accumulator pump in response to pressure within said accumulator in combination with said drive motor.