Compact well pumping unit actuated by linear motor with counterweight directly attached to slider

Abstract

A compact well pumping unit actuated by a linear motor with one or more counterweights directly attached to the slider. In one embodiment, two slider units are joined to form a rectangular complex around a two-sided stator track mounted vertically inside of a vertical steel frame. A belt assembly connects the slider complex to the polished rod of the well pump. The belt assembly passes over a first set of pulley wheels mounted on top of the vertical steel frame and a second set mounted on the side of the vertical steel frame. Thus when the slider complex caused to moves up and down, the polished rod of the well pump is actuated by the linear motor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of provisional application Ser. No. 60 / 857,622, filed Nov. 8, 2006, the contents of such application being hereby incorporated by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT[0003]Not applicable.INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC[0004]Not applicableBACKGROUND OF THE INVENTION[0005]1. Field of the Invention[0006]This invention generally relates to a new apparatus for actuating a sucker rod pump on an oil well.[0007]2. Background Art[0008]For oil production, sucker rod pumps are typically installed in oil wells to extract the oil below which do not have enough pressure to rise to the surface. Oil is extracted by reciprocating the up and down motion of the sucker rod. Different means have been employed to actuate the sucker rod. The most popular prior art apparatus utilize...

AI Technical Summary

Benefits of technology

[0020]Some of the objectives of the present invention include constructing a pumping unit that is made more durable by having less moving parts and more compact by eliminating the use of a counterweight that hangs outside of the vertical support structure. In addition, the pumping unit in the present invention is less top heavy since only one pair of pulley wheels is mounted on top of the vertical support structure. By utilizing two symmetrical sliders on a two-sided stator plate, the linear motor of the preferred embodiment is designed to be more powerful and efficient. Furthermore, the clearance distance between the slider and the stator track can be adjusted to further maximize the power and efficiency of the linear motor. Lastly, the present invention is less prone to vibrations since each slider unit rolls on a precise rail attached to the stator plate.

[0021]The present invention also incorporates other useful features. The preferred embodiment incorporates an automatic cooling fan to prevent the expensive electromagnetic coils in the slider from overheating, an automatic electromagnetic emergency brake system to safeguard the linear motor in case of emergency, and soft bumpers placed above and below the stator track to soften any possible impact the sliders would have on the pumping unit structure.

Problems solved by technology

Traditional pumping units are not efficient because energy is lost when rotational force from a rotary motor is converted to a linear motion using a gearbox and oscillating walking beam.

These pumping units are vulnerable to vibrations produced by the linear motor.

Uneven magnetic forces between the slider and the stator can cause vibrations.

This could weaken seals inside the well leading to oil and / or natural gas leakage.

In addition, such vibrations may gradually deform the downhole casing pipes.

Since the linear motor in these designs is fixed on top of the well, maintenance and service of the wellhead and downhole components are more difficult.

Furthermore, because the linear motor is fixed on the wellhead, the wellhead unit cannot withstand large pressure.

Thus, extra cost for an additional design is required for the wellhead unit to withstand large pressure.

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