TEMPERATURE SENSOR USING AN OPTICAL FIBER

• US 20090123109A1
• Filed: 10/24/2008
• Published: 05/14/2009
• Est. Priority Date: 11/09/2007
• Status: Abandoned Application

• Current Assignee: LxDATA Inc. (Weatherford International PLC)
• Original Assignee: LxDATA Inc. (Weatherford International PLC)
• Inventors: ZHOU, Bai, MIVILLE, Sebastien, VINCELETTE, Andre R.
• Application Number:
  US12/257,906
• Publication Number:
  US 20090123109A1
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: G01K 11/3206 at discrete locations in the fibre, e.g. using Bragg scattering

Abstract

A temperature sensor that has an elongated sensing element having a length of at least 10 m, measured at a temperature of 20° C. The elongated sensing element includes an elongated jacket and an optical fiber mounted in the jacket and having an EFL of at least 0.35%, wherein the elongated sensing element has an average temperature error of less than 2° C.

Claims

1. A temperature sensor, comprising:

an elongated sensing element having a length of at least 10 m, measured at a temperature of 20°

C., the elongated sensing element including;

an elongated jacket;

an optical fiber mounted in the jacket and having an EFL of at least 0.35%; and

the elongated sensing element having an average temperature error of less than 2°

C.

2. A temperature sensor as defined in claim 1, wherein the elongated sensing element has an average temperature error of less than 1°

C.

3. A temperature sensor as defined in claim 2, wherein the elongated sensing element has an average temperature error of less than 0.2°

C.

4. A temperature sensor as defined in claim 1, wherein the optical fiber has an EFL of at least 0.50%.

5. A temperature sensor as defined in claim 4, wherein the optical fiber has an EFL of at least 0.70%.

6. A temperature sensor as defined in claim 1, wherein the elongated sensing element has a length of not less than 100 m.

7. A temperature sensor as defined in claim 6, wherein the elongated sensing element has a length of not less than 500 m.

8. A temperature sensor as defined in claim 7, wherein the elongated sensing element has a length of not less than about 1 km.

9. A temperature sensor as defined in claim 1, wherein the jacket is characterized by a CTEjacket, the optical fiber is characterized by a CTEfiber, and a ratio CTEjacket/CTEfiber has a value of at least about 1.0001.

10. A temperature sensor as defined in claim 9, wherein the ratio CTEjacket/CTEfiber has a value of at least about 10.

11. A temperature sensor as defined in claim 10, wherein the ratio CTEjacket/CTEfiber has a value of at least about 20.

12. A temperature measurement system, comprising:

an elongated sensing element having a length of at least 10 m, measured at a temperature of 20°

C., the elongated sensing element including;

an elongated jacket;

an optical fiber mounted in the jacket and having an EFL of at least 0.35%;

the elongated sensing element having an average temperature error of less than 2°

C.;

the optical fiber defining an optical path for conveying an optical signal, the optical path manifesting an interaction with the optical signal, the interaction producing a measurable response, the response conveying information about temperature to which the optical fiber is exposed; and

a measurement component coupled to the optical fiber to sense the response and for deriving from the response information on the temperature to which the optical fiber is exposed.

13. A temperature measurement system as defined in claim 12, wherein the elongated sensing element has an average temperature error of less than 1°

C.

14. A temperature measurement system as defined in claim 13, wherein the elongated sensing element has an average temperature error of less than 0.2°

C.

15. A temperature measurement system as defined in claim 12, wherein the optical fiber has an EFL of at least 0.50%.

16. A temperature measurement system as defined in claim 15, wherein the optical fiber has an EFL of at least 0.70%.

17. A temperature measurement system as defined in claim 12, wherein the elongated sensing element has a length of not less than 100 m.

18. A temperature measurement system as defined in claim 17, wherein the elongated sensing element has a length of not less than 500 m.

19. A temperature measurement system as defined in claim 18, wherein the elongated sensing element has a length of not less than about 1 km.

20. A temperature measurement system as defined in claim 12, wherein the jacket is characterized by a CTEjacket, the optical fiber is characterized by a CTEfiber, a ratio CTEjacket/CTEfiber has a value of at least about 1.0001.

21. A temperature measurement system as defined in claim 20, wherein the ratio CTEjacket/CTEfiber has a value of at least about 10.

22. A temperature measurement system as defined in claim 21, wherein the ratio CTEjacket/CTEfiber has a value of at least about 20.

23. A temperature measurement system as defined in claim 12, wherein the measurement component is operative for deriving from the response information on the temperature to which the optical fiber is exposed at a plurality of spaced apart locations along the length of the sensing element.

24. A temperature measurement system as defined in claim 23, wherein the optical fiber includes a plurality of spaced apart gratings having a temperature dependant response to optical interrogation.

25. A temperature measurement system as defined in claim 23, wherein the interaction is a continuous interaction that occurs along the optical path, wherein the interaction produced back-scattering, the measurement component sensing the back-scattering.

26. A temperature sensor, comprising:

an elongated sensing element having a length of at least 10 m, measured at a temperature of 20°

C., the elongated sensing element including;

an elongated jacket;

an optical fiber mounted in the jacket and having an EFL of at least 0.35%; and

the elongated sensing element having an S value of at least about 1 mm2 per percent of EFL.

27. A temperature sensor as defined in claim 26, wherein the elongated sensing element has an S value of at least about 6.25 mm2 per percent of EFL.

28. A temperature sensor as defined in claim 27, wherein the elongated sensing element has an S value of at least about 10 mm2 per percent of EFL.

29. A temperature sensor as defined in claim 26, wherein the optical fiber has an EFL of at least 0.50%.

30. A temperature sensor as defined in claim 29, wherein the optical fiber has an EFL of at least 0.70%.

31. A temperature sensor as defined in claim 26, wherein the elongated sensing element has a length of not less than 100 m.

32. A temperature sensor as defined in claim 31, wherein the elongated sensing element has a length of not less than 500 m.

33. A temperature sensor as defined in claim 32, wherein the elongated sensing element has a length of not less than about 1 km.

34. A temperature sensor as defined in claim 26, wherein the jacket is characterized by a CTEjacket, the optical fiber is characterized by a CTEfiber, and a ratio CTEjacket/CTEfiber has a value of at least about 1.0001.

35. A temperature sensor as defined in claim 34, wherein the ratio CTEjacket/CTEfiber has a value of at least about 10.

36. A temperature sensor as defined in claim 35, wherein the ratio CTEjacket/CTEfiber has a value of at least about 20.