Controller and method of controlling a rod pumping unit
AssigneeRavdos Holdings Inc.
InventorsOmar Al Assad, Rogier Sebastiaan Blom, Gary Hughes, Justin Edwin Barton, Peter Westerkamp
Life of this patent
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Abstract
A controller for operating a rod pumping unit at a pump speed. The controller includes a processor configured to operate a pump piston of the rod pumping unit at a first speed. The processor is further configured to determine a pump fillage level for a pump stroke based on a position signal and a load signal. The processor is further configured to reduce the pump speed to a second speed based on the pump fillage level for the pump stroke.
Claims23
A controller for operating a rod pumping unit at a pump speed, said controller comprising a processor configured to:
- operate a pump piston of the rod pumping unit at a first pump piston speed during a pump stroke;
- determine a pump fillage level for the pump stroke based on a position signal and a load signal;
- reduce the first pump piston speed to a second pump piston speed based on the pump fillage level and a severity of a fluid pound event for the pump stroke in anticipation of the fluid pound event within the pump stroke, wherein the severity of the fluid pound event is based on the transfer of a load from a rod to a standing valve;
- and
- increase the second pump piston speed, within the pump stroke, to a third pump piston speed after the fluid pound event.
A method of controlling a rod pumping unit, said method comprising:
- determining a pump piston position and a pump piston load;
- computing a pump fillage level based on the pump piston position and the pump piston load;
- operating the rod pumping unit at a first pump speed;
- reducing the first pump speed to a second pump speed based on the pump fillage level, a severity of a fluid pound event, and the pump piston position in anticipation of the fluid pound event, wherein the severity of the fluid pound event is based on the transfer of a load from a rod to a standing valve;
- and
- increasing the second pump speed to a third pump speed after the fluid pound event;
- wherein said determining, computing, operating, reducing and increasing are carried out within a single pump stroke.
A rod pumping unit, comprising:
- a pump comprising a pump piston and a barrel, said pump piston operable within said barrel;
- a rod coupled to a motor and said pump, said rod configured to operate said pump at a pump speed during a pump stroke having a downstroke and an upstroke;
- and
- a controller coupled to said motor and configured to:
- drive said pump piston on the downstroke at a first pump speed;
- decelerate said pump piston on the downstroke to make the pump speed equal to a second pump speed, wherein the second pump speed is based on a severity of a fluid pound event, wherein the severity of the fluid pound event is based on the transfer of a load from the rod to a standing valve;
- and
- accelerate said pump piston on the downstroke after said pump piston contacts a fluid surface within said barrel.
Dependencies are inferred from the claim text.