Downhole data transmission system

• US 6,670,880 B1
• Filed: 03/23/2001
• Issued: 12/30/2003
• Est. Priority Date: 07/19/2000
• Status: Expired due to Term

• Current Assignee: IntelliServ, LLC (NOV, Inc.)
• Original Assignee: Novatek Engineering Incorporated
• Inventors: Hall, David R., Fox, Joe, Dahlgren, Scott, Hall, H. Tracy Jr., Pixton, David
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): Poker, Jennifer A
• Application Number:
  US09/816,766
• Time in Patent Office: 1,012 Days
• Field of Search: 336/132, 336/90, 339/16, 339/15, 339/84, 339/90, 439/194, 340/854
• US Class Current: 336/132
• CPC Class Codes: E21B 17/0285 characterised by electrically insulating elements
• CPC Class Codes: E21B 47/13 by electromagnetic energy, e.g. radio frequency
• CPC Class Codes: F16L 15/001 with conical threads
• CPC Class Codes: F16L 25/01 specially adapted for realising electrical conduction between the two pipe ends of the joint or between parts thereof
• CPC Class Codes: H01R 13/533 Bases, cases made for use in extreme conditions, e.g. high temperature, radiation, vibration, corrosive environment, pressure H01R13/52 takes precedence

Abstract

A system for transmitting data through a string of downhole components. In one aspect, the system includes first and second magnetically conductive, electrically insulating elements at both ends of the component. Each element includes a first U-shaped trough with a bottom, first and second sides and an opening between the two sides. Electrically conducting coils are located in each trough. An electrical conductor connects the coils in each component. In operation, a varying current applied to a first coil in one component generates a varying magnetic field in the first magnetically conductive, electrically insulating element, which varying magnetic field is conducted to and thereby produces a varying magnetic field in the second magnetically conductive, electrically insulating element of a connected component, which magnetic field thereby generates a varying electrical current in the second coil in the connected component.

Claims

1. A system for transmitting data through a string of downhole components comprising a plurality of joined downhole components, each downhole component comprising:

a first data transmission located proximate to a first end of each downhole component, which first includes a first magnetically conductive, electrically insulating trough, and a first electrically conducting coil lying therein;

a second data transmission located proximate to a second end of each downhole component, which second includes a second magnetically conductive, electrically insulating trough, and a second electrically conducting coil lying therein;

an electrical conductor in electrical communication with and running between each first and second coil in each component;

whereby the first data transmission in one of the plurality of downhole components is cooperatively arranged to be in magnetic, but not in electrical communication with the second data transmission of another one of the plurality of downhole components, when the downhole components are joined.

2. The system of claim 1 wherein the first and second troughs are U-shaped.

3. The system of claim 1 wherein the first and second conductive coils are encapsulated with an electrically insulating material.

4. The system of claim 1 wherein each trough comprises a bottom, a first side, a second side, and an opening between the two sides, and wherein each side has a top opposite the bottom of the trough, and wherein the first and second troughs are shaped and sized so as to allow the first and second conductive coils to lie in the bottom of the respective troughs and be separated a distance from the top of the respective first and second sides, whereby a surface of the component wherein the recess is formed can be machined without damaging the conductive coil lying therein.

5. The system of claim 1 wherein each downhole component includes a first recess formed proximate the first end with the first magnetically conductive, electrically insulating trough lying therein, and a second recess formed proximate the second end with the second magnetically conductive, electrically insulating trough lying therein.

6. The system of claim 5 wherein each recess is formed so as to open axially.

7. The system of claim 5 wherein each recess is formed so as to open radially.

8. The system of claim 1 wherein the system is used to transmit data along a drill string.

9. The system of claim 1 wherein the system is adapted to transmit data at a rate of at least 100 bits/second.

10. The system of claim 1 wherein the system is adapted to transmit data at a rate of at least 20,000 bits/second.

11. The system of claim 1 wherein the system is adapted to transmit data at a rate of at least 1,000,000 bits/second.

12. The system of claim 1 wherein the system is also used to transmit electrical power along the string of downhole components.

13. The system of claim 1 wherein the magnetically conductive, electrically insulating trough has a magnetic permeability greater than 40.

14. The system of claim 1 wherein the magnetically conductive, electrically insulating trough has a magnetic permeability greater than 100.

15. The system of claim 1 wherein the magnetically conductive, electrically insulating trough comprises ferrite.

16. The system of claim 15 wherein the ferrite has a magnetic permeability greater than 40.

17. The system of claim 1 wherein the magnetically conductive, electrically insulating trough comprises a magnetically soft metal in an electrically non-conductive structure.

18. The system of claim 17 wherein the structure is selected from the group consisting of a powdered magnetic material in an insulating matrix and a magnetic material between insulating layers.

19. The system of claim 3 wherein the electrically insulating material is selected from the group consisting of polyurethane, epoxy, silicone, rubber and phenolics, as well as combinations thereof.

20. The system of claim 1 wherein the first and second conductive coils are made from a single loop of insulated wire.

21. The system of claim 1 wherein the first and second conductive coils are made from at least two turns of insulated wire.

22. The system of claim 4 wherein the distance is at least 0.01 inches.

23. The system of claim 4 wherein the distance is at least 0.06 inches.

24. The system of claim 1 wherein the distance between the first and second troughs in connected components is less than 0.03 inches.

25. The system of claim 1 wherein the distance between the first and second troughs in connected components is less than 0.005 inches.

26. The system of claim 1 wherein the first and second troughs in connected components are touching.

27. The system of claim 1 further comprising an elongate hole in the downhole component, said hole being in communication with the first recess and adapted to receive the electrical conductor.

28. The system of claim 27 wherein the hole opens at one end into the first recess and opens at its other end into a hollow portion running through the component.

29. The system of claim 1 wherein the magnetically conductive, electrically insulating trough is formed in a unitary ring of a single magnetic conductive, electrically insulating material within the first and second recesses.

30. The system of claim 1 wherein the magnetically conductive material is formed into a split ring within the first and second recesses.

31. The system of claim 1 wherein the magnetically conductive material is formed into a unitary ring of more than one conductive material within the first and second recesses.

32. The system of claim 1 wherein the magnetically conductive material is formed in segments within the first and second recesses, each segment interspersed with magnetically nonconductive material.

33. The system of claim 1 wherein the system is adapted to transmit data through at least 10 components powered only by the varying current supplied to one of the first conductive coils in one of the components.

34. The system of claim 1 wherein the system is adapted to transmit data through at least 20 components powered only by the varying current supplied to one of the first conductive coils in one of the components.

35. The system of claim 1 wherein the varying current supplied to the first conductive coil in the one component is driving a varying potential having a peak to peak value of between 10 mV and 20 V.

36. The system of claim 1 further comprising amplifying units in at least some of the components for amplifying the data signals.

37. The system of claim 31 wherein each of the amplifying units is powered by a battery.

38. The system of claim 36 wherein the amplifying units are provided in no more than 10 percent of the components in the string of downhole components.

39. The system of claim 36 wherein any power loss between two connected components is less than 15 percent.

40. The system of claim 1 wherein any current loss between two connected components is less than 5 percent.

41. The system of claim 1 wherein the electrical conductor has an impedance and wherein the first and second electrically conductive coils have an impedance, and wherein a ratio of the impedance of the electrical conductor to the impedance of the first and second electrically conductive coils is between 1:

2 and 2;

1.

42. The system of claim 1 wherein the magnetically conductive, electrically insulating is formed in segments which are carried on a substrate, the substrate having a modulus of elasticity less than steel.

43. The system of claim 1 wherein the magnetically conductive, electrically insulating is formed in segments, with a compressible material between otherwise adjacent segments.

44. A downhole tool adapted to transmit data through the system of claim 1.

45. A downhole component including a system for transmitting data from one end to the other, the component comprising:

a first data transmission located proximate to a first end of each downhole component, which first includes a first magnetically conductive, electrically insulating trough, and a first electrically conducting coil lying therein;

a second data transmission located proximate to a second end of each downhole component, which second includes a second magnetically conductive, electrically insulating trough, and a second electrically conducting coil lying therein;

an electrical conductor in electrical communication with and running between each first and second coil in each component;

whereby the first data transmission at the first end of the downhole component is adapted to be in magnetic, but not in electrical communication with a third data transmission of another downhole component, when the downhole components are joined.

46. A system for transmitting data through a string of downhole components comprising a plurality of joined downhole components, each downhole component comprising:

a pin end and a box end, the pin end of one downhole component being adapted to be connected to the box end of another downhole component, each pin end comprising external threads tapering to a pin face, and each box end comprising internal threads tapering to a shoulder face within the box end, and wherein the pin face and shoulder face are aligned with and proximate each other when the pin end of the one component is threaded into a box end of the other component;

a first data transmission located in the pin end of each downhole component, which first includes a first magnetically conductive, electrically insulating trough, and a first electrically conducting coil lying therein;

a second data transmission located in the box end of each downhole component, which second includes a second magnetically conductive, electrically insulating trough, and a second electrically conducting coil lying therein;

an electrical conductor in electrical communication with and running between each first and second coil in each component;

whereby the first data transmission in one of the plurality of downhole components is cooperatively arranged to be in magnetic, but not in electrical communication with the second data transmission of another one of the plurality of downhole components, when the downhole components are joined, and wherein the magnetically conductive material of each magnetically conductive, electrically insulating trough comprises ferrite.

47. The system of claim 46 wherein the magnetically conductive material of each magnetically conductive, electrically insulating trough is formed in segments, each segment interspersed with magnetically nonconductive material.

48. The system of claim 46 wherein the system is adapted to transmit data at a rate of at least 100 bits/second.

49. The system of claim 46 wherein the system is adapted to transmit data at a rate of at least 1,000,000 bits/second.

50. The system of claim 46 wherein the first and second coils each include only one loop.

51. The system of claim 46 wherein the first and second coils each include only two loops.

52. The system of claim 46 wherein the system is adapted to transmit data through at least 10 components powered only by the varying current supplied to one of the first conductive coils in one of the components.

53. The system of claim 46 wherein the system is adapted to transmit data through at least 20 components powered only by the varying current supplied to one of the first conductive coils in one of the components.

54. The system of claim 46 further comprising amplifying units in at least some of the components for amplifying the data signals.

55. The system of claim 54 wherein the amplifying units are provided in no more than 10 percent of the components in the string of downhole components.

56. A downhole tool adapted to transmit data through the system of claim 46.