Low Profile Rod Pumping Unit with Pneumatic Counterbalance for the Active Control of the Rod String
AssigneeLufkin Industries, Inc.
InventorDavid W. Doyle
Life of this patent
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Abstract
Adaptable systems for a surface pumping unit that includes a low inertia pumping unit mechanism having a pneumatic counterbalance assembly are described, as well as methods for the use of such systems for subterranean fluid recovery. The system is capable of being integrated with well management automation systems, thereby allowing for response to active control commands, and automatically altering and/or maintaining a counterbalance force in the pumping unit by adding or removing air mass from a containment vessel associated with the pumping unit.
Claims3
A pumping unit for recovering underground fluid from a well, the unit comprising:
- a base disposed adjacent to the well;
- at least one support post mounted on the base, the support post extending upwardly and being connected to a center bearing;
- a walking beam pivotally mounted on the center bearing;
- a Pitman arm pivotally connected to the walking beam and extending downward from the walking beam;
- a crank assembly mounted on the base and operatively connected to the Pitman arm;
- a gear reducer mounted on and operatively connected to the crank assembly;
- is a drive unit mounted on the base and operatively connected to the gear reducer;
- and
- a pneumatic pressure vessel in operative communication with the pumping unit, the pressure vessel capable of automatically altering the compressible volume inside the pressure vessel for counterbalancing the pumping unit by displacing a portion of the compressible volume with an incompressible substance.
A device for actuating a rod of a sucker rod pump assembly, the device comprising;
- a rod;
- a motor;
- and
- a counterbalance assembly in communication with the motor,
- wherein the counterbalance assembly includes a pneumatic containment cylinder capable of altering and maintaining counterbalance force by adding or removing a fluid mass from the containment cylinder.
A method of pumping a fluid utilizing a sucker rod assembly, the sucker rod assembly comprising a rod, a motor, and a counterbalance assembly, the method comprising:
- positioning the sucker rod pump assembly such that the pump contacts a fluid reservoir;
- positioning the linear motor such that its axis of operation is substantially the same as the axis of movement of the sucker rod;
- providing a counterbalance assembly that includes at least one pneumatic pressure vessel positioned such that it automatically alleviates the load imposed on the motor by the sucker rod and the column of fluid to be pumped;
- and
- operating the motor such that the pump acquires fluid on its down stroke and transports fluid on its upstroke,
- wherein at least one pneumatic pressure vessel contains an incompressible substance capable of fluid communication between a separate reservoir and the pressure vessel.
Dependencies are inferred from the claim text.