Sealed ESP Motor System

Abstract

The present invention provides a submersible motor and pump system for use in a wellbore. More specifically, the present invention provides a submersible system having a sealed motor and a magnetic coupling to transmit torque from the sealed motor to the pump.

1 . A system for pumping fluids from a wellbore, comprising: 
 a motor having a motor shaft rotated by the motor around an axis, the motor shaft coupled to at least one driving magnet;    an expansion chamber in communication with the motor, the expansion chamber adapted to substantially equalize the internal pressure of the motor with the external pressure of the wellbore; and    a pump having a pump shaft coupled to at least one driven magnet,    wherein the pump is operated by rotation of the motor shaft and the at least one driving magnet to cause rotation of the at least one driven magnet and the pump shaft.    
   
   
       2 . The system of  claim 1 , wherein the motor and pump are deployed in the wellbore.  
   
   
       3 . The system of  claim 1 , wherein the at least one driving magnet comprises a plurality of driving magnets arranged in axially spaced rings disposed about the axis.  
   
   
       4 . The system of  claim 3 , wherein the at least one driven magnet comprises a plurality of driven magnets arranged in axially spaced rows concentric with the plurality of driving magnets.  
   
   
       5 . The system of  claim 1 , further comprising a shell disposed between the at least one driving magnet of the motor shaft and the at least one driven magnet of the pump shaft.  
   
   
       6 . The system of  claim 5 , wherein the shell prevents fluid communication between the motor and the pump.  
   
   
       7 . The system of  claim 5 , wherein the shell seals the motor from well fluids.  
   
   
       8 . The system of  claim 1 , wherein the expansion chamber comprises a flexible element housed within a pressurized chamber.  
   
   
       9 . The system of  claim 1 , wherein the expansion chamber comprises a bellows.  
   
   
       10 . The system of  claim 1 , wherein the expansion chamber comprises a piston.  
   
   
       11 . The system of  claim 1 , wherein the expansion chamber comprises a bellows affixed to a flexible element, the flexible element having an exterior surface in communication with wellbore fluid.  
   
   
       12 . The system of  claim 5 , further comprising an intermediate bearing disposed between the motor shaft and the shell.  
   
   
       13 . The system of  claim 5 , further comprising an intermediate bearing disposed between the shell and the pump shaft.  
   
   
       14 . The system of  claim 5 , further comprising an intermediate bearing disposed between the pump shaft and an exterior housing.  
   
   
       15 . The system of  claim 5 , further comprising: 
 an intermediate bearing disposed between the motor shaft and the shell;    an intermediate bearing disposed between the shell and the pump shaft; and    an intermediate bearing disposed between the pump shaft and an exterior housing.    
   
   
       16 . A sealed motor system for use in a submersible pumping system, comprising: 
 a motor;    a motor housing adapted to seal the motor from the surrounding environment;    a submersible pump;    a magnetic coupling adapted to transmit torque to the submersible pump by magnetic fields acting through the motor housing; and    a protector disposed between the magnetic coupling and the submersible pump.    
   
   
       17 . The sealed motor system of  claim 16 , wherein the magnetic coupling comprises rotors housing one or more permanent magnets.  
   
   
       18 . The sealed motor system of  claim 16 , wherein the motor housing comprises a thin-walled shell made of a high strength non-magnetic material.  
   
   
       19 . The sealed motor system of  claim 19 , wherein the motor housing comprises a thin-walled shell made of a non-conducting composite material.  
   
   
       20 . The sealed motor system of  claim 20 , wherein the non-conducting composite material is carbon-reinforced PEEK.