RELIABLE WIRED-PIPE DATA TRANSMISSION SYSTEM

• US 20120176138A1
• Filed: 12/23/2009
• Published: 07/12/2012
• Est. Priority Date: 01/02/2009
• Status: Active Grant

• Current Assignee: Nextstream Wired Pipe, LLC
• Original Assignee: Martin Scientific LLC
• Inventors: Prammer, Manfred G.
• Granted Patent: US 8,941,384 B2
• Time in Patent Office: Days
• US Class Current: 324/338
• CPC Class Codes: E21B 17/003 with electrically conducting or insulating means E21B17/028 and E21B17/023 take precedence
• CPC Class Codes: E21B 17/0285 characterised by electrically insulating elements
• CPC Class Codes: E21B 41/0085 Adaptations of electric power generating means for use in boreholes
• CPC Class Codes: E21B 47/12 Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
• CPC Class Codes: E21B 47/13 by electromagnetic energy, e.g. radio frequency
• CPC Class Codes: G01V 2003/084 Sources
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/18 specially adapted for well-logging
• CPC Class Codes: G01V 3/26 operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device with electromagnetic waves G01V3/30
• CPC Class Codes: G01V 3/28 using induction coils

Abstract

A high-frequency data and/or power transmission system suitable for down-hole use including signal/power couplers, transmission line segments and signal repeaters. Signals and power are/is transmitted between couplers and/or between couplers and repeaters by means of electromagnetic resonance coupling. In at least a portion of the system, the transmission line segments form parallel data paths and the repeaters provide crossover capability between the data/power paths, thereby significantly improving reliability. The invention also includes methods of transmitting data and/or distributing high-frequency power through a downhole transmission system including multiple data/power paths and multiple crossovers wherein a fault location in one data/power path is bypassed by routing data and/or power to a parallel data/power path by means of electromagnetic resonance coupling.

Claims

1. A downhole signal and/or power transmission system for providing communications and/or power along a string of interconnected downhole components, comprising:

a plurality of downhole components, at least one of said downhole components comprising;

a first end containing a pin electromagnetic coupler, said first end mechanically interconnecting with an end of a first adjacent downhole component containing a box electromagnetic coupler and said first end being electromagnetically coupled to said end of said first adjacent downhole component via said pin electromagnetic coupler; and

a second end containing a box electromagnetic coupler, said second end mechanically interconnecting with an end of a second adjacent downhole component containing a pin electromagnetic coupler and said second end being electromagnetically coupled to said end of said second adjacent downhole component via said box electromagnetic coupler,

wherein said electromagnetic couplers are constructed from non-magnetic materials and wherein said signal and/or power are exchanged among said downhole components by electromagnetic resonant coupling of high-frequency signals.

2. A downhole transmission system as in claim 1, wherein said at least one downhole component further comprises a plurality of electric conductors connecting the pin electromagnetic coupler in the first end to the box electromagnetic coupler in the second end through said downhole component so as to form a plurality of parallel data paths between said pin electromagnetic coupler and said box electromagnetic coupler.

3. A downhole transmission system as in claim 2, wherein an electric fault in one of said data paths is substantially decoupled by weak off-resonance coupling from the remainder of said plurality of said data paths and wherein said electric fault is substantially bypassed by means of electromagnetic coupling between said electromagnetic couplers.

4. A downhole transmission system as in claim 2, further comprising at least one signal repeater that is electromagnetically coupled to the box electromagnetic coupler in said second end of said downhole component and is electromagnetically coupled to said end of said second adjacent downhole component, wherein said signal repeater is tuned to said high-frequency signals and provides crossover capability between parallel data paths.

5. A downhole transmission system as in claim 4, wherein the second end of said downhole component houses said signal repeater.

6. A downhole transmission system as in claim 4, comprising a plurality of signal repeaters and at least one processor, wherein said processor:

receives message packets modulated on said high-frequency signals, said message packets traveling on said parallel data paths and arriving at said processor in multiple copies and at the same or different times;

detects faulty message packets; and

transmits correct message packets by generating said high-frequency signals, modulating said generated high-frequency signals with information, and coupling said modulated high-frequency signals to said parallel data paths.

7. A downhole transmission system as in claim 6, wherein at least one of said repeaters houses at least one of said processors.

8. A downhole transmission system as in claim 7, wherein a repeater that does not house at least one of said processors passively passes said high-frequency signals.

9. A downhole transmission system as in claim 4, wherein said interconnected downhole components have rotary connections and at least some of said rotary connections are adapted to accept said at least one signal repeater.

10. A downhole transmission system as in claim 9, wherein said rotary connections are of the double-shouldered type.

11. A downhole transmission system as in claim 1, wherein said electromagnetic resonant coupling occurs at frequencies within the HF, VHF or UHF bands between 10 MHz and 3 GHz.

12. A downhole transmission system as in claim 1, wherein said high-frequency signals having information modulated thereon.

13. A downhole transmission system as in claim 1, wherein said downhole components comprise pipe joints, pup joints, communication subs and/or repeater subs.

14. A downhole transmission system as in claim 1, wherein said pin electromagnetic coupler and said box electromagnetic coupler each comprises a substantially circular antenna placed in a groove that is filled with non-magnetic dielectric material.

15. A downhole transmission system as in claim 14, further comprising capacitors that match the electrical length of each antenna to the length of the groove in which it is placed.

16. A downhole transmission system as in claim 1,

wherein said pin electromagnetic coupler is separated from said end of said first adjacent downhole component by a first gap, said first gap containing electrically conductive or electrically insulating drilling fluids;

and/or

wherein said box electromagnetic coupler is separated from said end of said second adjacent downhole component by a second gap, said second gap containing electrically conductive or electrically insulating drilling fluids.

17. A downhole transmission system as in claim 4,

wherein said signal repeater is separated from said box electromagnetic coupler in said second end of said downhole component by a first gap, said first gap containing electrically conductive or electrically insulating drilling fluids;

and/or

wherein said signal repeater is separated from said pin electromagnetic coupler in said pin end of said second adjacent downhole component by a second gap, said second gap containing electrically conductive or electrically insulating drilling fluids.

18. A downhole transmission system as in claim 4, wherein said at least one repeater comprises a repeater box having a plurality of cavities adapted to accept electronic circuits and energy storage units.

19. A downhole transmission system as in claim 4, wherein at least one of said signal repeaters comprises a sensor circuit including a sensor, conditioning circuitry, an analog/digital converter, a processor and power-switching circuitry, wherein said sensor circuit is directed by said at least one signal repeaters to take sensor readings and to communicate sensor data.

20. A downhole transmission system as in claim 19, wherein said sensor data comprises local acceleration data, vibration data, and/or shock data gathered along said drill string.

21. A downhole transmission system as in claim 4, wherein at least one of said signal repeaters comprises a solenoidal coil of magnet wire, a permanent magnet that is loosely suspended within the solenoidal coil so as to move relative to the solenoidal coil as the drill string vibrates in the longitudinal direction and to thereby induce voltages in the solenoidal coil, a power conditioning circuit that captures the induced voltages, and a storage capacitor that stores captured induced energy.

22. A drill string signal and/or power coupling element for transmitting communications signals and/or power between drill string components and/or between elements of said drill string components, said components or elements being rotatable with respect to each other, comprising:

a first electromagnetic coupler mounted on a first of said rotatable components or elements;

a second electromagnetic coupler mounted on a second of said rotatable components or elements; and

a gap between said first and second electromagnetic couplers, said gap accommodating fluids that may be electrically conductive or electrically insulating,

wherein said electromagnetic couplers are constructed from non-magnetic materials and wherein said communications signals and/or power are exchanged between said rotatable components or elements by electromagnetic resonant coupling of high-frequency signals.

23. A coupling element as in claim 22, wherein said electromagnetic resonant coupling occurs at frequencies within the HF, VHF or UHF bands between 10 MHz and 3 GHz.

24. A coupling element as in claim 22, wherein said first electromagnetic coupler and said second electromagnetic coupler each comprises a substantially circular antenna placed in a groove that is filled with non-magnetic dielectric material.

25. A coupling element as in claim 24, further comprising capacitors that match the electrical length of each antenna to the length of the groove in which it is placed.

26. A method of providing communications along a string of downhole components comprising a plurality of interconnected downhole components having rotary connections, comprising the steps of:

generating high-frequency signals having information modulated thereon;

tuning a plurality of signal repeaters spaced along said string of downhole components to said high-frequency signals;

providing at least one downhole component having;

a first end containing a pin electromagnetic coupler, said first end mechanically interconnecting with an end of a first adjacent downhole component containing a box electromagnetic coupler and said first end being electromagnetically coupled to said end of said first adjacent downhole component via said pin electromagnetic coupler, said pin electromagnetic coupler constructed from non-magnetic materials,

a second end containing a box electromagnetic coupler, said second end mechanically interconnecting with an end of a second adjacent downhole component containing a pin electromagnetic coupler and said second end being electromagnetically coupled to said end of said second adjacent downhole component via said box electromagnetic coupler, said box electromagnetic coupler constructed from non-magnetic materials, and

a plurality of conductors connecting the pin electromagnetic coupler in the first end to the box electromagnetic coupler in the second end through said downhole component so as to form a plurality of parallel data paths between said pin electromagnetic coupler and said box electromagnetic coupler;

electromagnetically coupling said high-frequency signals from one of said first and second adjacent downhole components to said downhole component through said pin and box electromagnetic couplers by means of electromagnetic resonant coupling;

transmitting said high-frequency signals through at least one of said parallel data paths of said downhole component to a signal repeater; and

electromagnetically coupling said high-frequency signals from said signal repeater to the other of said first and second adjacent downhole components through said pin and box electromagnetic couplers by means of electromagnetic resonant coupling.

27. A method as in claim 26, further comprising the step of a signal repeater crossing said high-frequency signals from one parallel data path to another parallel data path.

28. A method as in claim 26, wherein said electromagnetic resonant coupling occurs at frequencies within the HF, VHF or UHF bands between 10 MHz and 3 GHz.

29. A method as in claim 26, further comprising the step of directing a sensor circuit of at least one of said signal repeaters to take sensor readings, and to communicate sensor data.

30. A method as in claim 26, wherein said sensor data comprises local acceleration data, vibration data, and/or shock data gathered along said drill string.

31. A method as in claim 26, further comprising the steps of inducing voltages in a solenoidal coil in response to vibration of the drill string and storing induced energy.

32. A method as in claim 26, further comprising directing a processor of at least one of said signal repeaters to process message packets, to discard and/or repair faulty packets, and to repeat correct and/or repaired message packets by generating and modulating a high-frequency signal.

33. A method of transmitting signals and/or power between drill string components and/or elements of said drill string components, said components or elements being rotatable relative to each other, comprising the steps of:

generating high-frequency signals having information modulated thereon;

providing a first electromagnetic coupler, said first coupler being constructed from non-magnetic material and mounted on a first component or element;

providing a second electromagnetic coupler, said second coupler being constructed from non-magnetic material and mounted on a second component or element;

providing a gap between said first and second electromagnetic coupler, said gap accommodating fluids that may be electrically conductive or electrically insulating; and

electromagnetically coupling said high-frequency signals from said first electromagnetic coupler to the second electromagnetic coupler through said gap and said fluids by means of electromagnetic resonant coupling.

34. A method as in claim 33, wherein said electromagnetic resonant coupling occurs at frequencies within the HF, VHF or UHF bands between 10 MHz and 3 GHz.