Abstract: A method for controlling a well pumping system is provided. The method includes the steps of entering a pump intake depth, a minimum fill preset, a maximum fill preset, and a gain value into a controller for the well pumping system, and determining a fluid over pump level. If the fluid over pump level is zero, the method calls for setting a target pump fill equal to the maximum fill preset. If the fluid over pump level is not zero, the method calls for calculating a fluid over pump ratio using the pump intake depth, and calculating the target pump fill using the fluid over pump ratio and the gain value. Further, the method includes calculating a pump fill error as the difference between the target pump fill and an actual pump fill. The method further includes controlling a pumping speed of the well pumping system based on the pump fill error.

Abstract: A method for operating a tandem motor linear rod pumping apparatus that includes first and second linear mechanical actuator systems each having a motor, and also includes a rod for a sucker-rod pump. The method calls for constructing the first and second linear mechanical actuator systems to operate within a single housing, and simultaneously operating each of the two motors in a manner that imparts reciprocating vertical motion to respective-vertically movable members of the first and second linear mechanical actuator systems. Each motor has a reversibly rotatable element that is operatively connected to the vertically-movable member of its respective linear mechanical actuator system, thus establishing a fixed relationship between the rotational position of the rotatable element and the vertical position of its respective vertically-movable member. The simultaneous operation of the two motors imparts a reciprocating vertical motion to the pump rod of the sucker-rod pump.

Abstract: An oil pumping system to carry oil from an oil sump in a pump housing to an internal oil reservoir in another portion of the pump housing. A top plate is attached to a pump rod and moves in accordance with a reciprocating motion of the pump rod. A bottom plate is below the top plate. A pump mechanism, disposed between the top plate and bottom plate, includes a valve seat that contacts the bottom plate, and an upper portion that contacts the top plate. A first biasing element is configured to urge the valve seat upward away from the bottom plate. A second biasing element is configured to urge the plunger upward away from the valve seat. Upward movement of the pump rod allows oil to flow into the pump mechanism. Downward movement of the pump rod causes the bottom of the valve seat to seal against the bottom plate.

Abstract: A method of operating an electric induction motor with a variable-speed drive includes determining a voltage level on a DC bus for the drive, and measuring a first magnitude of magnetic flux from a stator of the normally-operating electric motor, determining a normal flux level. The method includes disabling a first output to the drive when the DC bus voltage is less than a first threshold level. The method includes measuring a magnetic flux feedback signal having a phase and second magnitude, estimating a speed of the electric motor, and configuring a second output signal for the drive when the DC bus voltage is greater than a second threshold level. The second output signal matches a signal from the second magnitude and a phase of magnetic flux. The method includes enabling the drive output to restart the electric motor when the magnetic flux is greater than a third threshold value.

Abstract: A method is disclosed for balancing loss energy distribution in a drive circuit which drives a resonant load. The method includes the steps of using a plurality of switches to modulate a flow of electrical energy to a resonant load, and providing each of the plurality of switches with a diode connected in anti-parallel to its respective switch. The method further includes generating a voltage-modulated waveform across the resonant load which results in a first amount of loss energy distributed equally among the plurality of switches, and a second amount of loss energy distributed equally among the diodes.

Abstract: A dual completion linear rod pumping apparatus for imparting reciprocating vertical motion to a pair of rods for respective sucker-rod pumps. The dual completion linear rod pumping apparatus includes first and second linear mechanical actuator systems disposed in a single housing. These linear mechanical actuator systems impart and control vertical motion of the pair of rods. Each linear mechanical actuator system includes a rack and pinion gearing arrangement. The rack is operatively connected in a gear-mesh relationship with the pinion. The pinion is operatively connected to a rotating output of a motor. Rotation of the motor in a first direction results in an upward motion of the rack and connected sucker rod pump. Rotation of the motor in a second direction opposite the first direction results in a downward motion of the rack and connected sucker rod pump. An electronic controller is operatively connected to the motor.

Abstract: A tandem motor linear rod pumping apparatus for imparting reciprocating, substantially-vertical motion to a pump rod for a sucker-rod pump. The tandem motor linear rod pumping apparatus includes first and second linear mechanical actuator systems disposed in a single housing. These linear mechanical actuator systems impart and control vertical motion of the pump rod. Each linear mechanical actuator system includes a rack and pinion gearing arrangement. Each rack is operatively connected with two pinions. Each pinion is operatively connected to a motor. Rotation of the two motors in a first direction results in an upward motion of the rack and connected sucker rod pump. Rotation of the two motors in a second direction, opposite the first direction, results in a downward motion of the rack and sucker rod pump. The tandem motor linear rod pumping apparatus includes at least one electronic controller to control the operation of the two motors.