Wellbore Motor Having Magnetic Gear Drive

Abstract

A wellbore motor includes a source of rotational motive power disposed in a wellbore, a magnetic gear member operatively coupled at an input thereof to the source; and a magnetic gear member output coupled rotationally to a rotary wellbore tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a drilling rig moving a drill string in a wellbore to drill a wellbore through Earth formations.

FIG. 2 shows one embodiment of a fluid-driven, geared motor used in the drill string of FIG. 1.

FIG. 3 shows a cross section of the reduction gear section of the geared motor of FIG. 2.

FIG. 3A shows a perspective view of the embodiment shown in FIG. 3.

FIG. 4 shows an alternative embodiment of a magnet section using electromagnets.

FIG. 5 shows a cross section of one implementation of a wellbore motor according to the invention used with a wellbore completion valve.

FIG. 6 shows an electric submersible wellbore pump using a magnetic gear member according to the invention.

FIG. 7 shows a rod driven wellbore pump using a magnetic gear member according to the invention.

FIG. 8 shows a magnetic gear member according to the invention used between a rotary steerable directional drilling system and a drill bit.

Claims

1. A geared wellbore motor, comprising: a source of rotational motion disposed in a wellbore;a magnetic gear member rotationally coupled at an input thereof to the source; anda rotary wellbore tool rotationally coupled to an output of the magnetic gear member tool.

2. The motor of claim 1 wherein the source comprises an electric motor.

3. The motor of claim 2 wherein the rotary wellbore tool comprises a pump.

4. The motor of claim 1 wherein the source comprises rods extending to the Earth's surface from within the wellbore.

5. The motor of claim 4 wherein the rotary wellbore tool comprises a pump.

6. The motor of claim 1 wherein the source comprises a drill string disposed in the wellbore and extending to a drilling rig at the Earth's surface.

7. The motor of claim 6 wherein the rotary wellbore tool comprises a drill bit.

8. The motor of claim 6 wherein the magnetic gear member is disposed between the drill string and a drill bit.

9. The motor of claim 8 further comprising a rotary steerable directional drilling device rotationally coupled in the drill string between the lower end thereof and the input to the magnetic gear member, and wherein the drill bit is rotationally coupled to the output of the magnetic gear member.

10. 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.

11. The motor of claim 10 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.

12. The motor of claim 11 wherein a number of the magnets is selected to provide a selected rotational speed ratio between the input shaft and the output shaft.

13. The motor of claim 10 wherein the magnets comprise permanent magnets.

14. The motor of claim 10 further comprising a flux closure disposed about a radial exterior of the plurality of magnets.

15. The motor of claim 14 wherein the magnets are enclosed on a radial interior by an erosion barrier.

16. The motor of claim 10 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.

17. The motor of claim 16 wherein a number of the pole pieces is selected to provide a selected ratio of speed between the input shaft and the output shaft.

18. The motor of claim 17 wherein the pole pieces are enclosed by an erosion barrier.

19. The motor of claim 10 wherein the input shaft comprises a plurality of magnets circumferentially disposed about the drive shaft, the magnets enclosed by an erosion barrier.

20. The motor of claim 19 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.

21. The motor of claim 19 wherein the magnets on the input shaft are enclosed by an erosion barrier.

22. The motor of claim 10 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.

23. The motor of claim 10 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.

24. The motor of claim 10 wherein the source is rotationally coupled to the input shaft such that axial force on the source is isolated from the input shaft.

25. The motor of claim 10 wherein at least one of the magnets comprises an electromagnet.

26. The motor of claim 25 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.

27. A magnetically geared wellbore motor, comprising: a drill string extended into a wellbore and coupled to a drilling rig at the Earth's surface;an input shaft rotationally coupled to the drill string in the wellbore, 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; anda driving device rotationally coupled to the output shaft and configured to drive a drill bit.

28. The motor of claim 27 wherein at least one of the magnets comprises an electromagnet.

29. The motor of claim 28 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.

30. The motor of claim 27 wherein the driving device is 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.

31. The motor of claim 27 further comprising a rotary steerable directional drilling device coupled in the drill string between the lower end thereof and an input to the magnetic gear member.

32. A wellbore pump, comprising: a motor disposed in the wellbore, the motor supplied by power from a source external to the wellbore;a magnetic gear member rotationally coupled at an input thereof to an output of the motor; anda pump coupled at its input to an output of the magnetic gear member.

33. The pump of claim 32 wherein the motor comprises an electric motor.

34. The pump of claim 32 wherein the magnetic gear member comprises an input shaft rotationally coupled to the motor, an output shaft disposed externally to the input shaft, and a magnet section disposed externally to an output shaft rotationally coupled to the pump, the input shaft, the output shaft and the magnet section disposed inside a housing.

35. The pump of claim 34 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.

36. The pump of claim 35 wherein a number of the magnets is selected to provide a selected rotational speed ratio between the input shaft and the output shaft.

37. The pump of claim 35 wherein the magnets comprise permanent magnets.

38. The pump of claim 35 further comprising a flux closure disposed about a radial exterior of the plurality of magnets.

39. The pump of claim 35 wherein the magnets are enclosed on a radial interior by an erosion barrier.

40. The pump of claim 34 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.

41. The pump of claim 40 wherein a number of the pole pieces is selected to provide a selected ratio of speed between the input shaft and the output shaft.

42. The pump of claim 40 wherein the pole pieces are enclosed by an erosion barrier.

43. The pump of claim 34 wherein the input shaft comprises a plurality of magnets circumferentially disposed about the drive shaft, the magnets enclosed by an erosion barrier.

44. The pump of claim 43 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.

45. The pump of claim 43 wherein the magnets on the input shaft are enclosed by an erosion barrier.

46. The pump of claim 34 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.

47. The motor of claim 34 wherein the motor is rotationally coupled to the input shaft such that axial force on the motor is isolated from the input shaft.

48. The pump of claim 35 wherein at least one of the magnets comprises an electromagnet.

49. The pump of claim 48 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.