Pump Drive Unit for Water, Oil or Other Fluid Extraction

Abstract

A reciprocating seesaw-type (upward-downward) pump drive unit for water, oil, or other fluid extraction; the pump drive unit uses a pumping rod string that allows pumping fluids from depths of thousands of meters. This unit can be used in any well operated with mechanical pumping, without making any changes to the existing installation, achieving a reduction of around 20 % in pumping and operating equipment costs. The drive unit includes a piston ( 2 ) that slides up and down inside a vertical hydraulic cylinder ( 4 ) with the application of an actuating fluid, and where the piston shaft ( 2 ) is the rod string's polished rod ( 1 ).

Having described and specified the nature and scope of the invention and its implementation, exclusive rights and ownership are hereby claimed: 
     
         1 . Pump drive unit for water, oil or other fluid extraction able of providing a reciprocating motion (upward/downward) to a pumping unit through a pumping rod string (a); the drive unit includes a piston ( 2 ) that slides up and down inside a vertical hydraulic cylinder ( 4 ) as a result of the application of an actuating fluid, characterized in that the piston shaft ( 2 ) is the sucker rod string's polished rod ( 1 ). 
     
     
         2 . Pump drive unit for water, oil or other fluid extraction in accordance with  claim 1 , characterized in that the coupling of the piston ( 2 ) to the polished rod ( 1 ) of the pumping string ( 1 ) includes a lower well connection flange ( 7 ) with a seat ( 7   a ) against which rests an upper flange ( 6 ) for the hydraulic cylinder ( 4 ), and in which said upper flange ( 7 ) has a tab ( 20 ) to support the hydraulic cylinder ( 4 ); located on the lower flange ( 7 ) and threaded into the polished rod ( 1 ) of the rod string there is a seal assembly. 
     
     
         3 . Pump drive unit for water, oil or other fluid extraction in accordance with  claim 2 , characterized in that the seal assembly includes a body ( 11 ) housing a guide ring on the top ( 12 ) in contact with the piston ( 2 ); underneath the guide ring there is a housing ( 13 ) with a first hydraulic seal, and next to it a guide bushing ( 14 ); under the guide bushing ( 14 ), there is a cavity ( 15 ) that makes up a second stage hydraulic seal; below this second hydraulic seal stage there is a third hydraulic seal stage ( 16 ) in the body ( 11 ) of the seal assembly that can separate the hydraulic fluid from the extraction fluid in which there are also wipers ( 22 ) for the rod string's polished rod ( 1 ). 
     
     
         4 . Pump drive unit for water, oil or other fluid extraction in accordance with  claim 1 , characterized in that at the end of the rod string's polished rod ( 1 ) and over the piston ( 2 ) there is at least one spacer ( 18 ) attached by a coupling ( 19 ) threaded to the end of the rod string's polished rod ( 1 ).