CPC E21B 43/122 (2013.01) [E21B 33/068 (2013.01)] | 13 Claims |
1. An apparatus to operate a plunger catcher used with a plunger-assisted gas lift system, the apparatus, comprising:
a case having a mounting member for coupling the case in a fixed position relative to a lubricator on a wellhead, the case having an aperture to receive a plunger rod;
an electric motor connectable to a source of electrical current and having an output shaft controllably rotatable by the electric motor, at least a portion of the output shaft being within an interior of the case;
a current sensor to detect the current being provided to the electric motor and to generate a signal corresponding to the sensed current;
a processor/controller activatable by a signal from a plunger sensor disposed proximal to the lubricator of the wellhead, to receive the signal from the current sensor, to compare the signal from the current sensor to a set point, and to generate a control signal to the electric motor to generate a predetermined amount of torque to the output shaft; and
a lever arm coupled to the output shaft of the electric motor at a first end of the lever arm, and coupled to the plunger rod at the second end of the lever arm;
wherein rotation of the output shaft by the electric motor rotates the lever arm to extend the plunger rod outwardly from the case; and
wherein upon producing the predetermined amount of torque to the output shaft, the electric motor continues to produce that amount of torque until the control signal is changed.
|