Surface driven well pump

Abstract

Oil is recovered from a borehole using a pump using a surface driven high rotary speed pump. In one aspect, the pump is a centrifugal pump, operated at speeds in excess of 3400 rpm. The pump is located in a downhole position, within a production zone of a wellbore. A drive rod extends from a wellhead, downwardly through the wellbore, where it is received in engagement with the impeller of the pump. A dampening element is disposed in conjunction with the rod to reduce the physical excursion of the rod and thus enable high-speed rotation of the rod with minimal risk of excursion related failure of the rod or wellbore.

1 . A downhole pumping apparatus for pumping fluids from a wellbore, comprising: 
 a barrier extending along at least a portion of the wellbore to isolate an interior region of the wellbore from the adjacent earth;    a pump positionable in the wellbore in a producing region thereof;    a sleeve extending from the opening of the wellbore at the earth's surface to the centrifugal pump;    a drive member located outwardly of the bore;    a drive rod extending within said sleeve and interconnected to said pump and said drive motor; and    a dampening element positioned in contact with said drive rod within the wellbore when said drive rod is actuated by said motor to operate said pump.    
   
   
       2 . The downhole pumping apparatus of  claim 1 , wherein said pump is a centrifugal pump.  
   
   
       3 . The downhole pumping apparatus of  claim 1 , wherein said drive member is an electric motor.  
   
   
       4 . The downhole pumping apparatus of  claim 1 , wherein said drive member rotates said drive rod.  
   
   
       5 . The downhole pumping apparatus of  claim 1 , wherein said lubricant is an oil maintained in an annulus formed between said sleeve and said drive rod.  
   
   
       6 . The downhole pumping apparatus of  claim 1 , wherein said drive means rotates said drive rod in excess of 3400 rpm.  
   
   
       7 . The downhole pumping apparatus of  claim 1 , wherein said rod includes at least one mass imbalance portion therein.  
   
   
       8 . A lifting apparatus for lifting fluids from a downhole location to a location adjacent the opening of the wellbore to the earth's surface; comprising: 
 a drive member locatable adjacent the opening of the borehole to the earth's surface;    a pump locatable in a downhole location;    a rod, extending from said drive member to said pump; said drive member configured to enable rotation of said rod;    a sleeve disposed about said rod over at least a portion thereof extending within the wellbore; and    a dampening element disposed between said sleeve and said rod.    
   
   
       9 . The lifting apparatus of  claim 8 , wherein said pump is a centrifugal pump.  
   
   
       10 . The lifting apparatus of  claim 8 , wherein said dampening element is a fluid maintainable between said rod and said sleeve.  
   
   
       11 . The lifting apparatus of  claim 8 , further including production tubing extending from said pump to a location adjacent the opening of the wellbore in the earth; and 
 said pump includes a pump outlet in fluid communication with said production tubing.    
   
   
       12 . The lifting apparatus of  claim 11 , wherein said production sleeve extends within, and is substantially surrounded by, said production tubing.  
   
   
       13 . The lifting apparatus of  claim 8 , further including casing extending along at least a portion of the borehole.  
   
   
       14 . A method of recovery of fluids from a borehole, wherein the fluids exist at a pressure in the borehole insufficient to naturally drive them to the surface of their own accord, comprising: 
 providing a pump in the borehole and having a fluid inlet, a fluid outlet, and an energy transfer mechanism to transfer energy to the well fluids sufficient cause them to be lifted to the opening of the borehole with the earth's surface;    positioning a drive member at a location remote from the pump to provide energy transferred through rotary motion to the pump;    extending an energy transfer mechanism from the pump to the drive member, the energy transfer member including an excursion-dampening element; and    pumping fluids from the wellbore.    
   
   
       15 . The method of  claim 14 , wherein the pump is a centrifugal pump.  
   
   
       16 . The method of  claim 14 , wherein the excursion-dampening member includes a drive rod received in a sleeve, and a lubricant positioned between the sleeve and the rod.  
   
   
       17 . The method of  claim 14 , wherein said pump includes at least one impeller received within a diffuser housing and the impeller is rotatably driven by a rod extending down the wellbore from a drive mechanism located adjacent said wellhead.  
   
   
       18 . The method of  claim 14 , wherein the drive rod includes at least one mass imbalance region therein.  
   
   
       19 . A downhole pumping apparatus, comprising: 
 a centrifugal pump stack having an inlet, an outlet, and a plurality of impellers and diffuser housings in fluid communication therein received in a wellbore;    a drive rod extendible from a surface location, downwardly through said wellbore, and in physical coupled engagement with at least one of said impellers;    a drive member located adjacent to said wellbore and in physical driving engagement with said drive rod outwardly of said wellbore;    said drive rod including a naturally occurring excursion element therein; and    an excursion prevention element disposed in relation to said drive rod to prevent excursion of said drive rod.    
   
   
       20 . The pumping apparatus of  claim 19 , wherein said drive member includes a motor coupled to said drive rod, and said drive rod is rotated thereby at speeds in excess of 3400 rpm.  
   
   
       21 . The pumping apparatus of  claim 19 , wherein said excursion prevention mechanism includes: 
 a sleeve extending about the drive rod and forming an annulus therebetween therewith; and    a lubricant maintained within said annulus.    
   
   
       22 . The pumping apparatus of  claim 19 , wherein said excursion element is a mass imbalance portion of said drive rod.  
   
   
       23 . The pumping apparatus of  claim 19 , further including a production tube extending from a location in the well adjacent said surface location to a position coupled to said pump; 
 said pump includes a pump outlet coupled to the interior of said production tube; and    said sleeve extends within said wellbore within said production tube.    
   
   
       24 . The apparatus of  claim 21 , wherein said lubricant is oil.