DOWNHOLE DETECTION

• US 20140239959A1
• Filed: 03/13/2013
• Published: 08/28/2014
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Petrowell Limited (Weatherford International PLC)
• Inventors: Clarkson, Hugh
• Granted Patent: US 9,677,397 B2
• Time in Patent Office: Days
• US Class Current: 324/338
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: E21B 47/13 by electromagnetic energy, e.g. radio frequency
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

A system for use in downhole detection comprises a downhole arrangement defining a throughbore and a tool deployable through the throughbore of the downhole arrangement. The system further comprises a primary electromagnetic element provided on one of the downhole arrangement and the deployable tool and a secondary electromagnetic element provided on the other of the downhole arrangement and the deployable tool, wherein the primary and secondary electromagnetic elements are configurable for electromagnetic coupling therebetween. Such a system may be used for determining a status and/or an identity of a downhole tool in an oil or gas well from a determined degree of electromagnetic coupling between the primary and secondary electromagnetic elements.

Claims

1. A system for use in downhole detection comprising:

a downhole arrangement defining a throughbore;

a tool deployable through the throughbore of the downhole arrangement;

a primary electromagnetic element provided on one of the downhole arrangement and the deployable tool; and

a secondary electromagnetic element provided on the other of the downhole arrangement and the deployable tool,

wherein the primary and secondary electromagnetic elements are configurable for electromagnetic coupling therebetween.

2. A system according to claim 1, wherein the downhole arrangement comprises a downhole tool.

3. A system according to claim 1, wherein the downhole arrangement is configurable for at least one of fluid injection, stimulation, fracturing and production.

4. A system according to claim 1, wherein the deployable tool comprises a shifting tool for actuating the downhole arrangement.

5. A system according to claim 1, wherein the primary and secondary electromagnetic elements are configurable for electromagnetic coupling at a frequency in the range of 10 kHz to 1 MHz, 50 kHz to 500 kHz, or 100 kHz to 150 kHz.

6. A system according to claim 1, comprising a controller which is configured to generate and apply an electrical signal to the primary electromagnetic element, measure an electrical signal existing on the primary electromagnetic element, and determine a degree of electromagnetic coupling between the primary and secondary electromagnetic elements from the measured electrical signal.

7. A system according to claim 6, wherein the controller is configured to determine a degree of electromagnetic coupling between the primary and secondary electromagnetic elements according to a shape of a frequency spectrum of the measured electrical signal.

8. A system according to claim 6, wherein the controller is configured to determine a degree of electromagnetic coupling between the primary and secondary electromagnetic elements according to a shape or Q-factor of a resonant feature in the frequency spectrum of the measured electrical signal.

9. A system according to claim 6, wherein the controller is configured to log the determined degree of electromagnetic coupling between the primary and secondary electromagnetic elements in a memory.

10. A system according to claim 6, wherein the deployable tool comprises the controller.

11. A system according to claim 6, wherein the controller is configured for communication to surface.

12. A system according to claim 6, wherein the system comprises a power source for providing power to the controller.

13. A system according to claim 12, wherein the deployable tool comprises the power source.

14. A system according to claim 1, wherein the primary electromagnetic element is provided on the deployable tool and the secondary electromagnetic element is provided on the downhole arrangement.

15. A system according to claim 14, wherein the primary electromagnetic element comprises a coil of wire arranged helically around a body portion of the deployable tool, the wire comprising an electrically conductive core surrounded by an electrically insulating outer layer.

16. A system according to claim 14, wherein the primary electromagnetic element is encapsulated in a potting compound.

17. A system according to claim 14, wherein the deployable tool comprises a primary enclosure and the primary electromagnetic element is housed within the primary enclosure.

18. A system according to claim 17, wherein the primary enclosure is filled with a potting compound.

19. A system according to claim 17, wherein the primary enclosure comprises a generally tubular base member and a generally tubular lid member, and the primary electromagnetic element is wrapped around the base member.

20. A system according to claim 19, wherein at least the lid member of the primary enclosure is transparent to an electromagnetic field at a frequency in the range of 10 kHz to 1 MHz, 50 kHz to 500 kHz, or 100 kHz to 150 kHz.

21. A system according to claim 14, wherein the secondary electromagnetic element is configured so that an electrical signal existing on the primary electromagnetic element when the primary and secondary electromagnetic elements are electromagnetically coupled has a predetermined frequency spectrum.

22. A system according to claim 21, wherein the predetermined frequency spectrum has a predetermined shape.

23. A system according to claim 21, wherein the predetermined frequency spectrum includes a resonant feature having a predetermined shape or a predetermined Q-factor.

24. A system according to claim 23, wherein the resonant feature has a predetermined resonant frequency for a given temperature and/or pressure to which the secondary electromagnetic element is exposed.

25. A system according to claim 14, wherein the secondary electromagnetic element extends around the throughbore of the downhole arrangement.

26. A system according to claim 14, wherein the secondary electromagnetic element comprises a coil of wire arranged helically about the throughbore of the downhole arrangement, the wire comprising an electrically conductive core surrounded by an electrically insulating outer layer.

27. A system according to claim 14, wherein the secondary electromagnetic element comprises a capacitor electrically connected between two ends of the core.

28. A system according to claim 14, wherein the secondary electromagnetic element is encapsulated in a potting compound.

29. A system according to claim 14, wherein the downhole arrangement comprises a secondary enclosure and the secondary electromagnetic element is housed within the secondary enclosure.

30. A system according to claim 29, wherein the secondary enclosure is filled with a potting compound.

31. A system according to claim 29, wherein the secondary enclosure comprises a generally tubular base member and a generally tubular lid member which define a generally annular cavity therebetween, the annular cavity having a radial extent selected so as to avoid electromagnetic coupling between the secondary electromagnetic element and a body portion of the downhole arrangement.

32. A system according to claim 31, wherein the secondary electromagnetic element is wrapped around the base member.

33. A system according to claim 31, wherein at least the base member of the secondary enclosure is transparent to an electromagnetic field at a frequency in the range of 10 kHz to 1 MHz, 50 kHz to 500 kHz, or 100 kHz to 150 kHz.

34. A system according to claim 14, wherein the secondary electromagnetic element comprises a plurality of coils of wire distributed axially along the downhole arrangement, each coil of wire extending helically around the throughbore of the downhole arrangement, the wire of each coil of wire comprising an electrically conductive core surrounded by an electrically insulating outer layer, and each coil of wire configured such that electromagnetic coupling of each coil with the primary electromagnetic element provides a corresponding measured electrical signal having a characteristic frequency spectrum.

35. A system according to claim 14, wherein the secondary electromagnetic element comprises an electrically conductive ring extending around the throughbore of the downhole arrangement.

36. A system according to claim 35, wherein the ring is defined by an annular portion of the downhole arrangement.

37. A system according to claim 35, wherein the secondary electromagnetic element comprises a plurality of rings distributed axially along a longitudinal axis of the downhole arrangement, each ring extending around the throughbore of the downhole arrangement.

38. A system according to claim 37, wherein each ring is configured such that electromagnetic coupling of each ring with the primary electromagnetic element provides a corresponding measured electrical signal having a characteristic frequency spectrum.

39. A system according to claim 38, wherein the configuration of a ring is defined at least in part by an inner profile of the ring.

40. A system according to claim 38, wherein the configuration of a ring is defined at least in part by an inner diameter of the ring.

41. A system according to claim 38, wherein the configuration of a ring is defined at least in part by a material from which the ring is formed.

42. A system according to claim 38, wherein the configuration of a ring is defined at least in part by an axial extent of the ring.

43. A system according to claim 38, wherein the configuration of each ring is selected from a finite set of different ring configurations.

44. A system according to claim 43, wherein the finite set of ring configurations comprises a plurality of data ring configurations and a checking ring configuration which is different from the data ring configurations.

45. A system according to claim 44, wherein the plurality of rings defines a series of rings in which a checking ring configured according to the checking ring configuration is included repeatedly.

46. A system according to claim 45, wherein the plurality of rings defines a series of rings in which a checking ring configured according to the checking ring configuration is included with a regular axial periodicity.

47. A system according to claim 45, wherein alternate rings in the series of rings are checking rings configured according to the checking ring configuration.

48. A system according to claim 43, wherein the plurality of rings defines a series of rings in which a series of ring configurations is repeated at least once.

49. A system according to claim 43, wherein the secondary electromagnetic element comprises an axially inner plurality of rings, a first axially outer plurality of rings, and a second axially outer plurality of rings, and the series of ring configurations of the first axially outer plurality of rings and the second axially outer plurality of rings are different to one another and to the series of ring configurations of the axially inner plurality of rings.

50. A system according to claim 14, wherein the downhole arrangement is configurable between a first configuration in which electromagnetic coupling between the primary and secondary electromagnetic elements is prevented and a second configuration in which the secondary electromagnetic element is accessible by an electromagnetic field generated by the primary electromagnetic element.

51. A system according to claim 50, wherein the downhole arrangement is configurable between the first and second configurations on actuation or de-actuation of the downhole arrangement.

52. A system according to claim 50, wherein the downhole arrangement comprises a cover member, the secondary electromagnetic element is arranged radially outwardly of the cover member relative to a longitudinal axis of the throughbore of the downhole arrangement, and the secondary electromagnetic element and the cover member are moveable relative to one another.

53. A system according to claim 52, wherein the cover member extends at least partially between the secondary electromagnetic element and the throughbore of the downhole arrangement in the first configuration and the cover member is at least partially withdrawn from between the secondary electromagnetic element and the throughbore of the downhole arrangement in the second configuration.

54. A system according to claim 14, wherein the secondary electromagnetic element is accessible for electromagnetic coupling with the primary electromagnetic element regardless of a status of the downhole arrangement.

55. A system according to claim 14, wherein the downhole arrangement comprises a further secondary electromagnetic element configurable for electromagnetic coupling with the primary electromagnetic element, wherein the further secondary electromagnetic element is accessible for electromagnetic coupling with the primary electromagnetic element regardless of a status of the downhole arrangement.

56. A system according to claim 55, wherein the further secondary electromagnetic element comprises one or more of the same features as the secondary electromagnetic element.

57. A system according to claim 56, wherein the further secondary electromagnetic element is configured for location downhole of the secondary electromagnetic element.

58. A downhole arrangement for use in downhole detection, the downhole arrangement defining a throughbore for deployment of a deployable tool therethrough and the downhole arrangement comprising an electromagnetic element configurable for electromagnetic coupling with a further electromagnetic element provided on the deployable tool.

59. A tool for use in downhole detection, the tool being deployable through a throughbore defined by a downhole arrangement and the tool comprising an electromagnetic element configurable for electromagnetic coupling with a further electromagnetic element provided on the downhole arrangement.

60. A method for use in downhole detection, the method comprising:

providing a primary electromagnetic element on one of a downhole arrangement and a tool deployable within a throughbore of the downhole arrangement;

providing a secondary electromagnetic element on the other of the downhole arrangement and the deployable tool, wherein the primary and secondary electromagnetic elements are configurable for electromagnetic coupling therebetween; and

aligning the primary and secondary electromagnetic elements.

61. A method according to claim 60, comprising:

applying an electrical signal to the primary electromagnetic element;

measuring an electrical signal existing on the primary electromagnetic element;

and measuring a degree of electromagnetic coupling between the primary and secondary electromagnetic elements from the measured electrical signal.

62. A method for determining a status of a downhole tool, comprising:

providing a primary electromagnetic element on a shifting tool deployable within a throughbore of the downhole tool;

providing a secondary electromagnetic element on the downhole tool;

applying an electrical signal to the primary electromagnetic element;

aligning the primary electromagnetic element with the secondary electromagnetic element;

measuring an electrical signal existing on the primary electromagnetic element; and

determining a degree of electromagnetic coupling between the primary and secondary electromagnetic elements from the measured electrical signal.

63. A method according to claim 62, comprising:

preventing any electromagnetic coupling between the primary and secondary electromagnetic elements; and

then

in response to actuation or de-actuation of the downhole arrangement, allowing electromagnetic coupling between the primary and secondary electromagnetic elements.

64. A method according to claim 62, comprising:

allowing any electromagnetic coupling between the primary and secondary electromagnetic elements; and

then

in response to actuation or de-actuation of the downhole arrangement, preventing any electromagnetic coupling between the primary and secondary electromagnetic elements.

65. A method according to claim 62, comprising:

determining a status of the downhole arrangement from the determined degree of electromagnetic coupling between the primary and secondary electromagnetic elements.

66. A method for identifying a downhole tool, comprising:

providing a primary electromagnetic element on a shifting tool deployable within a throughbore of the downhole tool;

providing a secondary electromagnetic element on the downhole tool;

applying an electrical signal to the primary electromagnetic element;

running the primary electromagnetic element past the secondary electromagnetic element;

monitoring an electrical signal existing on the primary electromagnetic element as the primary electromagnetic element is run past the secondary electromagnetic element; and

determining an identity of the downhole tool from the monitored electrical signal.

67. A method according to claim 66, wherein the downhole arrangement is located in a wellbore, and the method comprises:

monitoring a position along the wellbore of the primary electromagnetic element as the primary electromagnetic element is run past the secondary electromagnetic element; and

determining a position of the secondary electromagnetic element within the wellbore from the monitored position of the primary electromagnetic element.