Method and Apparatus for Fluid Pumping

Abstract

A fluid balanced hydraulic pump has a support tower that can be mounted over a well. At least one cylinder assembly is pivotally mounted within the support tower. A prime mover provides hydraulic fluid to the at least one cylinder assembly through a wedge spool control valve that provides precise speed control with minimal maintenance requirements. Stroke speed can be easily and quickly adjusted without the need for expensive, troublesome or complicated electronic equipment.

Description

STATEMENTS AS TO THE RIGHTS TO THE INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0001]NONEBACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention pertains to a hydraulic pumping unit. More particularly, the present invention pertains to a hydraulic pumping unit that provides precise rod speed control with minimal maintenance requirements.[0004]2. Brief Description of the Prior Art[0005]Liquid-producing subterranean reservoirs all have some level of energy or potential, frequently referred to as “reservoir pressure” that will force fluid (liquid, gas or a mixture) to areas of lower energy or potential. If a well penetrates such a reservoir, and if the pressure inside such a well is decreased below the reservoir pressure, fluids will feed into the well from said formation. However, depending on the depth of the reservoir and density of the fluid(s), the reservoir may not have sufficient reservoir pressure to push the fluid to the surfa...

AI Technical Summary

Benefits of technology

[0014]Said at least one hydraulic cylinder assembly can be beneficially mounted to said elongate tower assembly using a self-centering pivot mounting assembly. Said self-centering pivot mounting assembly ensures that said at least one hydraulic cylinder assembly finds the center of gravity, thereby preventing unwanted side loading on said at least one cylinder assembly.

[0016]The hydraulic pumping apparatus of the present invention is inexpensive, durable and simple to operate. Further, the hydraulic pumping apparatus of the present invention has a small footprint and can be directly mounted to wells having shallow to medium depths or, alternatively, skid supported for wells extending to deeper depths. The hydraulic pumping apparatus of the present invention further provides for precise rod speed control with minimal maintenance requirements. Stroke speed can be easily and quickly adjusted without the need for expensive, troublesome or complicated electronic equipment.

Problems solved by technology

However, depending on the depth of the reservoir and density of the fluid(s), the reservoir may not have sufficient reservoir pressure to push the fluid to the surface.

However, as a well continues to produce, reservoir pressure will often decrease as a reservoir depletes.

Further, in many reservoirs, formation water will eventually encroach into the wellbore, causing the lifting requirements to be much greater than for just oil and / or gas.

Either or both of these conditions can cause production from a well to decline, or possibly even cease entirely.

Said surface drive mechanisms can be large, cumbersome and difficult to install in many instances.

Further, such conventional surface drive mechanisms are typically complicated, and expensive to manufacture, operate and maintain.

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