Obstacle detection system for underground operations

• US 7,013,991 B2
• Filed: 08/17/2004
• Issued: 03/21/2006
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: Gas Technology Institute (GTI Energy)
• Original Assignee: Gas Technology Institute (GTI Energy)
• Inventors: Kothari, Kirankumar M., Hanson, David R., Inggs, Michael R., Wilson-Langman, Alan, du Toit, Leendert Johannes
• Primary Examiner(s): TSAY, FRANK
• Application Number:
  US10/919,748
• Publication Number:
  US 20050061547A1
• Time in Patent Office: 581 Days
• Field of Search: 175/48, 175/26, 175/38, 175/42, 175/40, 175/50, 340/435, 340/436, 340/437
• US Class Current: 175/48
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: E21B 7/04 Directional drilling

Abstract

An obstacle avoidance system for obstacle detection in an opaque material. The system includes at least one electromagnetic signal source adapted to produce an electromagnetic source signal suitable for transmission through the opaque material, at least one electromagnetic signal detector adapted to receive reflected electromagnetic energy signals from discontinuities in the opaque material encountered by the electromagnetic source signal, and a reflected electromagnetic energy signal processor suitable for determining a presence of obstructions and/or strata variations within the opaque material. The system is preferably integral with a head element suitable for traversing the opaque material, for example a subterranean drill bit.

Claims

1. An apparatus for obstacle detection in an opaque material comprising:

at least one electromagnetic signal source adapted to produce an electromagnetic source signal suitable for transmission through said opaque material;

at least one electromagnetic signal detector adapted to receive reflected electromagnetic energy signals from discontinuities in said opaque material encountered by said electromagnetic source signal;

a reflected electromagnetic energy signal processor suitable for determining a presence of at least one of obstructions and strata variations within said opaque material; and

a head element having a leading edge and a trailing edge, said head element suitable for traversing at least a portion of said opaque material, and said at least one electromagnetic signal source, said at least one electromagnetic signal detector and said at least one reflected electromagnetic energy signal processor disposed at least one of in contact with said head element and proximate to said head element.

2. An apparatus in accordance with claim 1, wherein said head element comprises a subterranean cutting tool.

3. An apparatus in accordance with claim 1, wherein said at least one electromagnetic signal source and said at least one electromagnetic signal detector are integrated into a transceiver.

4. An apparatus in accordance with claim 3, wherein said transceiver is integral with said head element.

5. An apparatus in accordance with claim 1, wherein said head element comprises a drill bit operably connected to a drill string, said drill string adapted to provide communication between said drill bit and a human machine interface device operably connected to an opposite end of said drill string.

6. An apparatus for obstacle detection in an opaque material comprising:

communication and radar controller means for controlling at least one radar module to enable capture of radar profiles;

sampler and controller means for controlling a radar transceiver and an antenna and sampling an intermediate frequency signal operably connected to said communication and radar controller means;

transmit synthesizer means for generating at least one radar transmit waveform operably connected to said sampler and controller means;

RF demodulation means for demodulating a received RF signal down to said intermediate frequency operably connected to said antenna and said sampler and controller means; and

IF cancellation means for improving a dynamic range of said apparatus operably connected to said sampler and controller means.

7. An apparatus in accordance with claim 6, wherein said communication and radar controller means is operably connected to said sampler and controller means by a first radar module link, said sampler and controller means is operably connected to said transmit synthesizer means by a second radar module link, and said sampler and controller means is operably connected to said antenna by a third radar module link.

8. An apparatus in accordance with claim 6 further comprising a human machine interface operably connected to said communication and radar controller means.

9. An apparatus in accordance with claim 6, wherein said communications and radar controller means, said sampler and controller means, said transmit synthesizer means, said RF demodulator means, said IF cancellation means and said antenna are disposed within a head element suitable for traversing said opaque material.

10. An apparatus in accordance with claim 9, wherein said head element is a drill bit suitable for subterranean boring.

11. An apparatus in accordance with claim 8, wherein said human machine interface and said communications and radar controller means are operably connected to each other by wireless communications.

12. An apparatus in accordance with claim 7, wherein each of said radar module links comprises a low voltage differential signaling electrical interface.

13. An apparatus in accordance with claim 6, wherein said transmit synthesizer means and said RF demodulator means together constitute a radar transceiver.

14. An apparatus in accordance with claim 13, wherein said radar transceiver comprises separate transmit and receive synthesizers.

15. An apparatus in accordance with claim 6 further comprising a modulation scheme selected from the group consisting of stepped frequency continuous wave radar, impulse radar, frequency modulated continuous wave radar, and noise radar.

16. An apparatus comprising:

a controllable head element suitable for traversing an opaque material; and

an obstacle avoidance system disposed one of in said controllable head element, on an outer surface of said controllable head element, and proximate said controllable head element, said obstacle avoidance system comprising a system selected from the group consisting of stepped frequency continuous wave radar, impulse radar, frequency modulated continuous wave radar and noise radar.

17. An apparatus in accordance with claim 16, wherein said obstacle avoidance system comprises said stepped frequency continuous wave radar system.

18. An apparatus in accordance with claim 17, wherein said stepped frequency continuous wave radar system comprises a communications and radar controller module, a sampler and controller module operably connected to said communications and radar controller module, and a radar transmitter module, a radar receiver module, an antenna module, an RF demodulator module and an IF cancellation module operably connected with said sampler and controller module.

19. An apparatus in accordance with claim 17 further comprising a human machine interface disposed distal from said controllable head element operably connected to said stepped frequency continuous wave radar system.

20. An apparatus in accordance with claim 18 further comprising at least one radar module link operably connected to at least one of said modules, thereby providing communications and a reference clock to all said modules.

21. An apparatus in accordance with claim 20, wherein said at least one radar module link comprises two low voltage differential signaling pairs, one bi-directional line and one clock line.

22. An apparatus in accordance with claim 20, wherein said at least one radar module link comprises a bi-directional, fair multiple-access, serial communication protocol operable with one clock and one data signal.

23. An apparatus in accordance with claim 18, wherein said antenna module comprises a surrounding media adaptable antenna.