Wellbore motor having magnetic gear drive

• US 20070125578A1
• Filed: 11/27/2006
• Published: 06/07/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Magnomatics Limited
• Original Assignee: Deter Magnetic Technologies Incorporated
• Inventors: McDonald, William, Price, Timothy, Hatch, Gareth
• Granted Patent: US 7,481,283 B2
• Time in Patent Office: Days
• US Class Current: 175/107
• CPC Class Codes: E21B 4/006 Mechanical motion converting means, e.g. reduction gearings E21B4/10 takes precedence
• CPC Class Codes: F16H 49/005 Magnetic gearings with physical contact between gears rotating torque transmitting elements of the permanent-magnet type H02K49/102
• CPC Class Codes: H02K 49/102 Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact magnetized gearings with physical contact F16H13/12, F16H49/005

Abstract

A wellbore motor includes a means for converting flow of fluid in the wellbore into rotational energy. A magnetic gear member is operatively coupled at an input thereof to the means for converting. A wellbore rotary tool is coupled to an output of the magnetic gear member.

Claims

1. A wellbore motor, comprising:

means for converting flow of fluid in the wellbore into rotational energy;

a magnetic gear member operatively coupled at an input thereof to the means for converting; and

a magnetic gear member output adapted to couple rotationally to a rotary wellbore tool.

2. The motor of claim 1 wherein the means for converting comprises a turbine.

3. The motor of claim 1 wherein the wellbore rotary tool comprises a drill bit.

4. The motor of claim 1 wherein the magnetic gear member comprises an input shaft rotationally coupled to the means for converting, an output shaft disposed externally to the input shaft, and a magnet section disposed externally to the output shaft, the input shaft, the output shaft and the magnet section disposed inside a housing adapted to be coupled to a drill string.

5. The motor of claim 4 wherein the magnet section comprises a plurality of magnets circumferentially spaced about an interior of a magnet retainer, the magnet retainer having an external shape for cooperatively engaging an interior surface of the housing so as to prevent rotation therebetween.

6. The motor of claim 5 wherein a number of the magnets is selected to provide a selected rotational speed ratio between the input shaft and the output shaft.

7. The motor of claim 4 wherein the magnets comprise permanent magnets.

8. The motor of claim 4 further comprising a flux closure disposed about a radial exterior of the plurality of magnets.

9. The motor of claim 7 wherein the magnets are enclosed on a radial interior by an erosion barrier.

10. The motor of claim 4 wherein the output shaft comprises a plurality of ferromagnetic pole pieces circumferentially disposed about an exterior of a drive shaft member, the drive shaft member made from a non-magnetic material.

11. The motor of claim 10 wherein a number of the pole pieces is selected to provide a selected ratio of speed between the input shaft and the output shaft.

12. The motor of claim 9 wherein the pole pieces are enclosed by an erosion barrier.

13. The motor of claim 4 wherein the input shaft comprises a plurality of magnets circumferentially disposed about the drive shaft, the magnets enclosed by an erosion barrier.

14. The motor of claim 13 wherein a number of the magnets on the input shaft is selected to provide a selected rotational speed ratio between the input shaft and the output shaft.

15. The motor of claim 11 wherein the magnets on the input shaft are enclosed by an erosion barrier.

16. The motor of claim 4 wherein an exterior shape of the magnet section includes annular spaces between the exterior of the magnet section and an interior surface of the housing such that wellbore fluid is movable therethrough.

17. The motor of claim 4 wherein the output shaft is rotationally coupled to a threaded coupling adapted to threadedly couple to a drilling tool, the threaded coupling rotationally coupled to the output shaft so as to isolate axial load transfer between the output shaft and the threaded coupling, the threaded coupling having an axial thrust bearing associated therewith to transfer axial loading on the threaded coupling to the housing.

18. The motor of claim 4 wherein the means for rotating is rotatationally coupled to the input shaft such that axial force on the means for rotating is isolated from the input shaft.

19. The motor of claim 4 wherein at least one of the magnets comprises an electromagnet.

20. The motor of claim 19 further comprising a controller operatively coupled to the at least one electromagnet, the controller operative to activate and deactivate the at least one electromagnet in response to a control signal.

21. The motor of claim 1 wherein the rotary wellbore tool comprises a completion valve.

22. The motor of claim 21 wherein the magnetic gear member comprises an input shaft rotationally coupled to the means for converting, an output shaft disposed externally to the input shaft and rotationally coupled to a valve spool, and a magnet section disposed externally to the output shaft, the input shaft, the output shaft, the magnet section disposed inside a casing adapted to be disposed in a wellbore.

23. A magnetically geared wellbore drilling motor, comprising:

a turbine for converting flow of drilling fluid in the wellbore into rotational energy;

an input shaft rotationally coupled to the turbine, the input shaft having at least one magnet thereon;

an output shaft disposed rotatably about an exterior surface of the input shaft, the output shaft having thereon a plurality of circumferentially spaced apart pole pieces formed from ferromagnetic material;

a magnet section having a plurality of magnets disposed circumferentially about an exterior of the output shaft, the magnet section having a magnet retainer with an external shape adapted to cooperate with an interior of a housing in which the magnet section is disposed such that rotation between the magnet section and the housing is substantially prevented; and

a driving device rotationally coupled to the output shaft adapted to operate a rotary wellbore drilling tool, the driving device rotationally coupled to substantially isolate axial force on the drilling tool from the output shaft, the driving device arranged to transfer axial loading thereon to the housing.

24. The motor of claim 23 wherein at least one of the magnets comprises an electromagnet.

25. The motor of claim 24 further comprising a controller operatively coupled to the at least one electromagnet, the controller operative to activate and deactivate the at least one electromagnet in response to a control signal.

26. A magnetically geared, powered wellbore completion valve, comprising:

a turbine for converting flow of fluid in the wellbore into rotational energy;

an input shaft rotationally coupled to the turbine, the input shaft having at least one magnet thereon;

an output shaft disposed rotatably about an exterior surface of the input shaft, the output shaft having thereon a plurality of circumferentially spaced apart pole pieces formed from ferromagnetic material, the output shaft rotationally coupled to a valve spool;

a magnet section having a plurality of magnets disposed circumferentially about an exterior of the output shaft, the magnet section having a magnet retainer with an external shape adapted to cooperate with an interior of a housing in which the magnet section is disposed such that rotation between the magnet section and the housing is substantially prevented; and

at least one valve port in a casing proximate the valve spool, the port cooperating with a seal element on the valve spool such that rotation of the valve spool relative to the casing enables selective opening and closing of the completion valve, the at least one valve port when open providing hydraulic communication between an interior and an exterior of the casing.