Sealed ESP motor system

1. A submersible pumping system for deployment in a well, comprising:

a submersible pump;

a motor located within a housing sealed from contamination with well fluids; and

a magnetic coupling adapted to magnetically drive the submersible pump via the motor, wherein the dynamic stability of the magnetic coupling is enhanced by an intermediate bearing support having three intermediate bearings concentric with each other at the same axial position.

2. The submersible pumping system of claim 1 , further comprising a magnetic coupling adapted to transmit torque from the motor to the submersible pump.

3. The submersible pumping system of claim 2 further comprising a protector adapted to transmit torque from the magnetic coupling to the submersible pump.

4. The submersible pumping system of claim 1 further comprising a protector adapted to transmit torque to the submersible pump.

5. The submersible pumping system of claim 1 further comprising thrust bearings.

6. A system to transmit torque from motor to a pump for pumping well fluids, comprising:

a motor-side housing affixed to the motor;

a motor-side shaft rotatably driven by the motor;

a motor-side rotor affixed to the motor-side shaft and having at least one permanent magnet affixed thereto;

a protective shell affixed to the motor-side housing and adapted to seal the motor, motor-side shaft and the motor-side rotor from the surrounding well fluids;

a pump-side housing affixed to the pump;

a pump-side shaft adapted to drive the pump;

a pump-side rotor affixed to the pump-side shaft and having at least one permanent magnet affixed thereto; and

wherein the at least one permanent magnet affixed to the motor-side rotor interacts with the at least one permanent magnet affixed to the pump-side rotor to create a magnetic field that transmits through the protective shell to enable synchronous transmission of torque from the motor-side shaft to the pump-side shaft; and

an intermediate bearing support having three intermediate bearings concentric with each other at the same axial position.

7. The system of claim 6 , wherein the motor-side housing is welded to the motor.

8. The system of claim 6 , wherein the at least one permanent magnet of the motor-side rotor is arranged in rings.

9. The system of claim 6 , wherein the protective shell is made of a high strength, non-magnetic material.

10. The system of claim 6 , wherein the protective shell is made of a non-conducting composite material.

11. The system of claim 10 , wherein the composite material is carbon-reinforced PEEK.

12. The system of claim 6 , wherein the at least one permanent magnet affixed to the motor-side rotor is enclosed by a non-magnetic sleeve.

13. The system of claim 6 , wherein the at least one permanent magnet affixed to the pump-side rotor is enclosed by a non-magnetic sleeve.

14. The system of claim 6 , wherein the sealed motor is filled with clean oil.

15. The system of claim 6 , further comprising a pressure and volume compensating device affixed to the sealed motor.

16. A magnetic coupling for use in a submersible pumping system, comprising:

a motor sealed from well fluids by a protective housing;

a motor shaft within the protective housing having a plurality of magnets affixed thereto;

a pump having a pump housing;

a pump rotor located outside the protective housing and having a plurality of magnets affixed thereto magnetically linked to the magnets affixed to the motor shaft, wherein rotation of the motor shaft causes the pump rotor to rotate; and

one or more intermediate bearing supports, wherein the one or more intermediate bearing supports comprise tilt-pad bearings.

17. A magnetic coupling for use in a submersible pumping system, comprising:

a motor sealed from well fluids by a protective housing;

a motor shaft within the protective housing having a plurality of magnets affixed thereto;

a pump having a pump housing;

a pump rotor located outside the protective housing and having a plurality of magnets affixed thereto magnetically linked to the magnets affixed to the motor shaft, wherein rotation of the motor shaft causes the pump rotor to rotate; and

one or more intermediate bearing supports, wherein the one or more intermediate bearing supports comprise lemon bore bearings.

18. A magnetic coupling for use in a submersible pumping system, comprising:

a motor sealed from well fluids by a protective housing;

a motor shaft within the protective housing having a plurality of magnets affixed thereto;

a pump having a pump housing;

a pump rotor located outside the protective housing and having a plurality of magnets affixed thereto magnetically linked to the magnets affixed to the motor shaft, wherein rotation of the motor shaft causes the pump rotor to rotate; and

one or more intermediate bearing supports, wherein the one or more intermediate bearing supports comprise offset bearings.

19. A magnetic coupling for use in a submersible pumping system, comprising:

a motor sealed from well fluids by a protective housing;

a motor shaft within the protective housing having a plurality of magnets affixed thereto;

a pump having a pump housing;

a pump rotor located outside the protective housing and having a plurality of magnets affixed thereto magnetically linked to the magnets affixed to the motor shaft, wherein rotation of the motor shaft causes the pump rotor to rotate; and

one or more intermediate bearing supports, wherein the one or more intermediate bearing supports comprise elliptical bearings adapted to shape the protective housing elliptically.