Strain sensing cable

• US 8,746,074 B2
• Filed: 05/30/2012
• Issued: 06/10/2014
• Est. Priority Date: 05/30/2012
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Lambert, Christopher H.
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): WILLIAMS, JAMEL E
• Application Number:
  US13/483,694
• Publication Number:
  US 20130319126A1
• Time in Patent Office: 741 Days
• Field of Search: 737/60, 731/524.8, 731/524.9
• US Class Current: 73/760
• CPC Class Codes: D07B 1/145 comprising elements for indicating or detecting the rope or cable status
• CPC Class Codes: D07B 2301/259 Strain or elongation
• CPC Class Codes: D07B 2301/5577 using light guides
• CPC Class Codes: G01D 5/35316 using a Bragg gratings
• CPC Class Codes: G01D 5/3537 Optical fibre sensor using a particular arrangement of the optical fibre itself
• CPC Class Codes: G01L 1/242 the material being an optical fibre

Abstract

A sensing cable, including an outer cladding; and at least one sensing bundle contained within the cladding, each sensing bundle having a sensing fiber wrapped strain-transmissively by at least one strand. A method of sensing strain is also included.

Claims

1. A sensing cable, comprising:

an outer cladding;

a central member disposed in the outer cladding; and

at least one sensing bundle contained within the cladding, each sensing bundle having a sensing fiber wrapped strain-transmissively by at least one strand.

2. The sensing cable of claim 1, the at least one bundle being circumferentially wrapped about the central member.

3. The sensing cable of claim 1, wherein the at least one bundle extends axially and non-spirally within the outer cladding.

4. The sensing cable of claim 3, wherein the at least one bundle extends in parallel with the central member.

5. The sensing cable of claim 1, further comprising a filler material in the cladding encapsulating the at least one sensing bundle.

6. The sensing cable of claim 5, wherein the filler material is a plastic.

7. The sensing cable of claim 1, further comprising at least one tube disposed in the outer cladding.

8. The sensing cable of claim 7, wherein the tube includes at least one additional sensing fiber located therein.

9. The sensing cable of claim 8, wherein the tube and the at least one additional sensing fiber form a fiber in metal tube (FIMT) assembly.

10. The sensing cable of claim 7, wherein the at least one tube and the at least one sensing bundle are included about a central member.

11. The sensing cable of claim 10, wherein the central member is a wire.

12. The sensing cable of claim 10, wherein the at least one tube comprises a plurality of tubes and the at least one sensing bundle comprises a plurality of sensing bundles.

13. The sensing cable of claim 12, wherein the sensing bundles and the tube are alternatingly included about the central member.

14. The sensing cable of claim 12, wherein the sensing bundles and the tubes are circumferentially wrapped about the central member.

15. The sensing cable of claim 1, wherein the fiber includes fiber Bragg gratings.

16. A method of sensing strain comprising:

deploying a cable having at least one at least one sensing bundle contained within a cladding, each sensing bundle having a sensing fiber wrapped strain-transmissively by at least one strand, each of the sensing bundles being wrapped circumferentially about a central wire; and

transmitting strain to the fiber via the at least one strand.

17. The method of claim 16, further comprising sensing strain in the fiber by use of fiber Bragg gratings.

18. The method of claim 16, wherein the cable further comprises at least one tube in the cladding.

19. The method of claim 18, wherein the at least one tube includes at least one other fiber disposed therein.

20. The method of claim 19, further comprising monitoring an additional condition or parameter with the at least one other fiber.