Hydraulic pump jack sytem for reciprocating oil well sucker rods

Abstract

A pumping system for vertical reciprocation of a string of sucker rods within oil well tubing having a positive displacement pump at the bottom thereof, includes a vertically positioned elongated hydraulic cylinder supported above the tubing and in alignment therewith, the cylinder having a vertically displaceable piston therein. A pump rod is affixed to the piston and extends beyond the bottom end of the cylinder. A seal member affixed to the lower end of the cylinder sealably and reciprocally receives the piston rod. A Tee fitting is secured between the tubing and the cylinder bottom end and reciprocally receives the piston rod. A controlled hydraulic power system provides fluid pressure to the cylinder to vertically reciprocate the piston and thereby the piston rod and tubing string to pump crude oil upwardly in the tubing, the crude oil flowing under pressure into the Tee fitting and out through a side opening.

Description

REFERENCE TO PENDING APPLICATIONS [0001] This application is based on Provisional Patent Application 60 / 562,207 filed April 13, 2004 entitled PUMP APPARATUS AND METHOD FOR OIL WELL PRODUCTION.REFERENCE TO MICROFICHE APPENDIX [0002] This application is not referenced in any microfiche appendix. FIELD OF THE INVENTION [0003] This invention relates to a system for reciprocating an oil well pump located in the bottom portion of a string of tubing in which the pump is reciprocated by sucker rods extending from the pump to the earth's surface. BACKGROUND OF THE INVENTION [0004] Oil wells typically vary in depth from a few hundred feet to several thousand feet. In many wells there is insufficient subterranean pressure to force the oil to the earth's surface. For this reason some system must be devised for pumping the crude oil from the producing formation to the earth's surface. The most common system for pumping an oil well is by the installation of a pumping unit at the earth's surface t...

AI Technical Summary

Benefits of technology

"The present invention provides a hydraulic pump jack drive system for reciprocating a down hole oil well pump by using a sucker rod string. This system eliminates the need for a stuffing box, which saves time and money. The system also allows for full stroke of the pump, regardless of rod stretch, and reduces the risk of pipe line leaks and power factor penalties. The system is easy to install and cheaper to operate and maintain compared to existing pumping systems. The method includes using hydraulic fluid to raise the cylinder rod and sucker rod to load the down hole pump, holding the pump at the top of the stroke for a pre-determined time to allow for maximum fluid pump efficiency, and controlling the speed of the down stroke by adjusting a variable orifice valve."

Problems solved by technology

In many wells, and stripper wells in particular, the walking beam pumping system cannot run at a slow enough rate.

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