Sealless downhole system with magnetically supported rotor

Patent metadata

Field	Value
Publication number	US-10309200-B2
Application number	US-201816107824-A
Country	US
Kind code	B2
Filing date	Aug 21, 2018
Priority date	Sep 20, 2017
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A fluid module includes a fluid rotor configured to rotatably drive or be driven by fluid produced from a wellbore. A first shaft is coupled to the fluid rotor. The first shaft is configured to rotate in unison with the fluid rotor. A thrust bearing module includes a thrust bearing rotor. A second shaft is coupled to the thrust bearing rotor. The second shaft is configured to rotate in unison with the thrust bearing rotor. The second shaft is coupled to the first shaft. An electric machine module includes an electric machine rotor. A third shaft is coupled to the electric machine rotor. A third shaft is configured to rotate in unison with the electric machine rotor. The third shaft is coupled to the second shaft. The third shaft is rotodynamically isolated from the first shaft and the second shaft.

First claim

What is claimed is:

1. A downhole-type artificial lift system comprising:
a fluid module comprising:
a fluid rotor configured to rotatably drive or be driven by fluid produced from a wellbore;
a first shaft coupled to the fluid rotor, the first shaft configured to rotate in unison with the fluid rotor; and
a fluid stator that surrounds the fluid rotor;

a thrust bearing module comprising:
a thrust bearing rotor;
a second shaft coupled to the thrust bearing rotor, the second shaft configured to rotate in unison with the thrust bearing rotor, the second shaft coupled to the first shaft, the second shaft configured to transfer torque between the first shaft and the second shaft, the second shaft being rotodynamically isolated from the first shaft; and
a thrust bearing stator that surrounds the thrust bearing rotor; and

an electric machine module comprising:
an electric machine rotor;
a third shaft coupled to the electric machine rotor, the third shaft configured to rotate in unison with the electric machine rotor, the third shaft coupled to the second shaft or the first shaft, the third shaft configured to transfer torque between the second shaft and the third shaft or between the second shaft and the first shaft, the third shaft being rotodynamically isolated from the first shaft and the second shaft; and
an electric stator that surrounds the electric machine rotors;

wherein the system is configured to rotate the first shaft below a critical speed of the first shaft, rotate the second shaft below a critical speed of the second shaft, and rotate the third shaft below a critical speed of the third shaft.

2. The downhole-type artificial lift system of claim 1 , wherein the critical speed of the first shaft, the critical speed of the second shaft, and the critical speed of the third shaft are greater than a critical speed of a single shaft of equivalent length to a sum of a length of the first shaft, a length of the second shaft, and a length of the third shaft.

3. The downhole-type artificial lift system of claim 1 , wherein the system is configured to rotate the first shaft, the second shaft, and the third shaft at 10,000 revolutions per minute.

4. The downhole-type artificial lift system of claim 1 , wherein the system is configured to rotate the first shaft, the second shaft, and the third shaft at 120,000 revolutions per minute.

5. The downhole-type artificial lift system of claim 1 , wherein the fluid module is positioned at an uphole end of the system and the electric machine module is positioned at a downhole end of the system.

6. The downhole-type artificial lift system of claim 1 , wherein the fluid module further comprises:
a first magnetic radial bearing configured to support a first end of the first shaft to the fluid stator; and
a second radial magnetic bearing configured to support a second end of the first shaft to the fluid stator.

7. The downhole-type artificial lift system of claim 1 , wherein the electric machine module further comprises:
a first magnetic radial bearing configured to support a first end of the second shaft to the electric stator; and
a second radial magnetic bearing configured to support a second end of the second shaft to the electric stator.

8. The downhole-type artificial lift system of claim 1 , wherein the thrust bearing module comprises a magnetic thrust bearing.

9. The downhole-type artificial lift system of claim 8 , wherein the magnetic thrust bearing is an active magnetic thrust bearing.

10. The downhole-type artificial lift system of claim 1 , wherein the thrust bearing module further comprises:
a first magnetic radial bearing configured to support a first end of the second shaft to the thrust bearing stator; and
a second radial magnetic bearing configured to support a second end of the second shaft to the thrust bearing stator.

11. The downhole-type artificial lift system of claim 1 , wherein the fluid module is a first fluid module, the fluid rotor is a first fluid rotor, and the fluid stator is a first fluid stator, the downhole-type artificial lift system further comprising a second fluid module comprising:
a second fluid rotor configured to rotatably drive or be driven by fluid produced from a wellbore;
a fourth shaft coupled to the second fluid rotor, the fourth shaft configured to rotate in unison with the second fluid rotor, the fourth shaft being rotodynamically isolated from the first shaft, the second shaft, and the third shaft; and
a second fluid stator that surrounds the second fluid rotor.

12. The downhole-type artificial lift system of claim 1 , wherein the thrust bearing module is a first thrust bearing module, the thrust bearing rotor is a first thrust bearing rotor, and the thrust bearing stator is a first thrust bearing stator, the downhole-type artificial lift system further comprising a second thrust bearing module comprising:
a second thrust bearing rotor;
a fourth shaft coupled to the thrust bearing rotor, the fourth shaft configured to rotate in unison with the second thrust bearing rotor, the fourth shaft being rotodynamically isolated from the first shaft, the second shaft, and the third shaft; and
a second thrust bearing stator that surrounds the second thrust bearing rotor.

13. The downhole-type artificial lift system of claim 1 , wherein the electric machine module is a first electric machine module, the electric machine rotor is a first electric machine rotor, and the electric stator is a first electric stator, the downhole-type artificial lift system further comprising a second electric machine module comprising:
a second electric machine rotor;
a fourth shaft coupled to the second electric machine rotor, the fourth shaft configured to rotate in unison with the second electric machine rotor, the fourth shaft being rotodynamically isolated from the first shaft, the second shaft, and the third shaft; and
a second electric stator that surrounds the second electric machine rotor.

14. A method comprising:
radially magnetically levitating a first rotor within a first stator;
radially magnetically levitating a second rotor within a second stator;
radially magnetically levitating a third rotor within a third stator;
rotodynamically isolating the first rotor from the second rotor by a first rotodynamic isolator coupling; and
rotodynamically isolating the second rotor from the third rotor by a second rotodynamic isolator;
rotating the first shaft below a critical speed of the first rotor;
rotating the second shaft below a critical speed of the second rotor; and
rotating the third shaft below a critical speed of the third rotor.

15. The method of claim 14 , further comprising rotating the first rotor, the second rotor, and the third rotor in unison at 10,000 revolutions per minute.

16. The method of claim 14 , further comprising rotating the first rotor, the second rotor, and the third rotor in unison at 120,000 revolutions per minute.

17. The method of claim 14 , further comprising axially supporting the first rotor, the second rotor, and the third rotor with a magnetic thrust bearing.

18. The method of claim 14 , further comprising damping radial vibrations.

19. The method of claim 14 , further comprising:
exchanging torque between the first rotor and second rotor by a first rotodynamic isolator coupling, the first coupling configured to rotodynamically isolate the first rotor and second rotor from one another; and
exchanging torque between the second rotor and the third rotor by a second rotodynamic isolator coupling,

Assignees

• Upwing Energy Llc

Inventors

• Mcmullen Patrick
• Artinian Herman
• Chen Kuo-Chiang
• Biddick David

Classifications

• E21B47/008

  Monitoring of down-hole pump systems, e.g. for the detection of "pumped-off" conditions · CPC title

• F16C37/005

  of magnetic bearings · CPC title

• F04D13/064

  Details of the magnetic circuit · CPC title

• F16C32/0474

  for rotary movement · CPC title

• H02K11/27

  Devices for sensing current, or actuated thereby (overcurrent protection responsive to temperature of the machines or parts thereof, e.g. windings, H02K11/25) · CPC title