Method and apparatus for determining a trajectory of a directional drill

• US 7,114,580 B1
• Filed: 02/21/2003
• Issued: 10/03/2006
• Est. Priority Date: 02/21/2003
• Status: Expired due to Fees

• Current Assignee: Field Effects Calibration, LLC
• Original Assignee: MicroTesla, Ltd.
• Inventors: Balogh, W. Thomas
• Primary Examiner(s): NEUDER, WILLIAM P
• Application Number:
  US10/371,623
• Time in Patent Office: 1,320 Days
• Field of Search: 166/250.01, 166/255.1, 166/255.2, 175/24, 175/26, 175/40, 175/45, 175/57, 175/61, 175/62, 175/73, 340/853.1, 340/853.5, 340/853.6, 340/853.4, 731/520.1, 731/524.3, 731/524.6, 731/524.9, 333/40, 333/13, 356/139.03, 356/139.04, 356/139.1, 356/140, 356/634
• US Class Current: 175/45
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: G01C 1/00 Measuring angles
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means

Abstract

An apparatus for determining a trajectory of a directional drill includes two length measurement devices deployed along a surface of the drill string and a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices. A method includes determining at least two lengths along a surface of a drill string; and determining a heading of the drill string using the at least two determined lengths.

Claims

1. An apparatus for measuring a heading of a drill string, comprising

two length measurement devices deployed along a surface of the drill string, wherein at least one of the length measurement devices comprises:

a displacement detector; and

a cord deployed along at least one of the lengths of the drill string and coupled to the displacement detector; and

a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices.

2. The apparatus of claim 1, wherein the displacement detector comprises at least one of a linear variable displacement transducer, a force sensor, a force transducer, a rotary potentiometer, a cable extension transducer, and a linear potentiometer.

3. The apparatus of claim 1, wherein the cord comprises at least one of a wire, a cable, a string, a rod, a chain, a tape, a filament, and a rope.

4. An apparatus for measuring a heading of a drill string, comprising

two length measurement devices deployed along a surface of the drill string, wherein at least one of the length measurement devices comprises a portion of surveyor'"'"'s tape;

and

a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices.

5. An apparatus for measuring a heading of a drill string, comprising

two length measurement devices deployed along a surface of the drill string, wherein at least one of the length measurement devices comprises:

at least one strain gauge sensor; and

a signal processing unit capable of determining a length using the strain gauge sensor; and

a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices.

6. The apparatus of claim 5, wherein the at least one strain gauge sensor comprises at least one of a piezoelectric and a piezoresistive device.

7. An apparatus for measuring a heading of a drill string, comprising

two length measurement devices deployed along a surface of the drill string, wherein the two length measurement devices are deployed within two guides;

and

a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices.

8. A method, comprising:

determining at least two lengths along a surface of a drill string, wherein determining the at least two lengths along the surface of the drill string comprises determining the at least two lengths using at least two length measurement devices deployed within at least two guides positioned along the surface of the drill string; and

determining a heading of the drill string using the at least two determined lengths.

9. The method of claim 8, wherein determining the at least two lengths along the surface of the drill string comprises determining the at least two lengths using at least two surveyors tapes deployed within the at least two guides.

10. The method of claim 8, wherein determining the at least two lengths along the surface of the drill string comprises determining the at least two lengths using at least two cords deployed within the at least two guides, and wherein the at least two cords are coupled to at least two displacement detectors.

11. A method, comprising:

determining at least two lengths along a surface of a drill string, wherein determining the at least two lengths along the surface of the drill string comprises determining the at least two lengths using at least two strain gauge sensors; and

determining a heading of the drill string using the at least two determined lengths.

12. The method of claim 11, wherein determining the at least two lengths using the at least two strain gauge sensors comprises determining the at least two lengths using at least two strain gauge sensors deployed such that at least two lengths of the at least two strain gauge sensors correspond to the at least two determined lengths along the surface of the drill string.

13. An apparatus for measuring a heading of a drill string, comprising:

three cords deployed along the drill string;

three displacement detectors coupled to the three cords, the three displacement detectors being capable of determining three lengths corresponding to the three cords; and

a controller capable of determining the heading of the drill string using the three determined lengths.

14. The apparatus of claim 13, further comprising three guides coupled to the surface of the drill string.

15. The apparatus of claim 14, wherein the three cords are deployed within the three guides.

16. The apparatus of claim 13, wherein the surface of the drill string is an interior surface.

17. The apparatus of claim 13, wherein the surface of the drill string is an exterior surface.

18. The apparatus of claim 13, wherein the controller is capable of determining the heading of the drill string using two differences between the three determined lengths.

19. The apparatus of claim 13, wherein the controller is capable of determining a difference between the heading and a desired heading.

20. The apparatus of claim 19, wherein the controller is capable of providing a signal indicative of the difference between the heading and the desired heading.

21. The apparatus of claim 13, wherein the three cords are displaced angularly about an axis of the drill string.

22. The apparatus of claim 13, wherein the displacement detectors are spaced apart circumferentially about the drill string.

23. A system for trench-less directional drilling, comprising:

a drill string having a first end and a second end;

a drill bit deployed near the first end of the drill string;

at least two length measurement devices deployed along a surface of the drill string, wherein the at least two length measurement devices are capable of determining at least two lengths from the first end of the drill string to the second end of the drill string along the surface of the drill string, wherein at least one of the length measurement devices comprises;

a guide deployed substantially along the surface of the drill string;

a cord deployed in the guide; and

a displacement detector coupled to the cord and capable of providing a signal indicative of a length of the cord; and

a controller capable of;

determining a heading of the drill string using the at least two lengths;

determining a trajectory of the drill string based on the determined heading; and

controlling the drill bit such that the determined trajectory corresponds to a desired trajectory.

24. A system for down-hole directional drilling, comprising:

a first portion of a drill string, the first portion having a first end and a second end;

a drill bit deployed near the first end of the first portion of the drill string;

at least two length measurement devices deployed along a surface of the first portion, wherein the at least two length measurement devices are capable of determining at least two lengths from the first end to the second end along the surface of the first portion, wherein at least one of the length measurement devices comprises;

a strain gauge sensor; and

a signal processing unit capable of determining a length using the strain gauge sensor; and

a controller capable of;

determining a heading of the first portion using the at least two lengths;

determining a trajectory of the first portion based on the determined heading; and

controlling the drill bit such that the determined trajectory corresponds to a desired trajectory.

25. A system for down-hole directional drilling, comprising:

a first portion of a drill string, the first portion having a first end and a second end;

a drill bit deployed near the first end of the first portion of the drill string;

at least two length measurement devices deployed along a surface of the first portion, wherein the at least two length measurement devices are capable of determining at least two lengths from the first end to the second end along the surface of the first portion, wherein at least one of the length measurement devices comprises;

a guide deployed substantially along the surface of the first portion of the drill string;

a cord deployed in the guide; and

a displacement detector coupled to the cord and capable of providing a signal indicative of a length of the cord; and

a controller capable of;

determining a heading of the first portion using the at least two lengths;

determining a trajectory of the first portion based on the determined heading; and

controlling the drill bit such that the determined trajectory corresponds to a desired trajectory.

26. An apparatus for measuring a heading of a drill string, comprising:

two length measurement devices deployed along a surface of the drill string; and

a controller capable of determining the heading of the drill string from two lengths of the drill string measured by the two length measurement devices, the heading being determined on an axis parallel to the plane defined by the two measured lengths.

27. The apparatus of claim 26, wherein at least one of the length measurement devices comprises:

a displacement detector; and

a cord deployed along at least one of the lengths of the drill string and coupled to the displacement detector.

28. The apparatus of claim 27, wherein the displacement detector comprises at least one of a linear variable displacement transducer, a force sensor, a force transducer, a rotary potentiometer, a cable extension transducer, and a linear potentiometer.

29. The apparatus of claim 27, wherein the cord comprises at least one of a wire, a cable, a string, a rod, a chain, a tape, a filament, and a rope.

30. The apparatus of claim 26, wherein at least one of the length measurement devices comprises:

a transmission medium;

a signal source capable of transmitting a signal over the transmission medium;

a receiver capable of receiving the signal; and

a signal processing unit capable of determining a length of the transmission medium using the transmitted and received signals.

31. The apparatus of claim 26, wherein at least one of the length measurement devices comprises:

at least one strain gauge sensor; and

a signal processing unit capable of determining a length using the strain gauge sensor.

32. The apparatus of claim 26, wherein the controller is capable of determining a trajectory of the drill string using the determined heading.

33. The apparatus of claim 26, further comprising a third length measurement device deployed along the surface of the drill string, and wherein the controller is capable of determining the heading of the drill string from the three measured lengths of the drill string measured by the three length measurement devices.