SYSTEM AND METHOD FOR MONITORING STRUCTURES

• US 20110194107A1
• Filed: 04/18/2011
• Published: 08/11/2011
• Est. Priority Date: 03/14/2006
• Status: Abandoned Application

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: STRONG, Andrew, HARTOG, Arthur H., LEES, Gareth P., HILTON, Graeme
• Application Number:
  US13/089,188
• Publication Number:
  US 20110194107A1
• Time in Patent Office: Days
• US Class Current: 356/301
• CPC Class Codes: G01D 5/35303 using a reference fibre, e.g. interferometric devices
• CPC Class Codes: G01D 5/35354 Sensor working in reflection
• CPC Class Codes: G01D 5/35358 using backscattering to detect the measured quantity
• CPC Class Codes: G01H 9/004 using fibre optic sensors light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125
• CPC Class Codes: G01K 1/143 for measuring surface temperatures
• CPC Class Codes: G01K 11/32 using changes in transmittance, scattering or luminescence in optical fibres
• CPC Class Codes: G01M 11/086 Details about the embedment of the optical fiber within the DUT

Abstract

A technique facilitates the monitoring of elongate structures. An elongate structure is combined with an optical fiber deployed along the structure. An interrogation system is operatively joined with the optical fiber to input and monitor optical signals to determine any changes in parameters related to the structure.

Claims

1. A method of monitoring an elongate structure, comprising:

deploying a fiber optic cable along the elongate structure; and

using the fiber optic cable to determine a plurality of structure-related parameters indicative of a structural failure or potential structural failure of the elongate structure, wherein using the fiber optic cable to determine the plurality of structure-related parameters comprises combining a fast, high resolution measurement of a change along the fiber optic cable with a slower measurement of absolute temperature and strain along the fiber optic cable.

2. The method as recited in claim 1, wherein the elongate structure is a pipeline.

3. The method as recited in claim 1, wherein the elongate structure is an energy cable.

4. The method as recited in claim 1, wherein using the fiber optic cable to determine a plurality of structure-related parameters comprises monitoring both Brillouin backscatter and coherent Rayleigh noise to determine the plurality of structure-related parameters.

5. The method as recited in claim 4, wherein monitoring Brillouin backscatter comprises measuring strain and temperature along the elongate structure.

6. The method as recited in claim 4, wherein monitoring coherent Rayleigh noise comprises measuring disturbances along the elongate structure.

7. The method as recited in claim 4, wherein using the fiber optic cable to determine a plurality of structure-related parameters further comprises monitoring Raman backscatter.

8. The method as recited in claim 1, wherein the elongate structure is deployed at a subsea location.

9. The method as recited in claim 1, wherein the elongate structure is buried beneath the surface of the earth.

10. The method as recited in claim 1, wherein deploying the fiber optic cable comprises placing the fiber optic cable in contact with the elongate structure.

11. A method, comprising:

locating an optical fiber along an elongate structure;

monitoring an optical signal input through the optical fiber; and

detecting a disturbance to the structure of the elongate structure based on changes in the optical signal, wherein monitoring the optical signal input through the optical fiber comprises;

monitoring the optical signal for both Brillouin backscatter and coherent Rayleigh noise;

using the Brillouin backscatter for the measurement of temperature and strain; and

using the coherent Rayleigh noise for the measurement of strain transients.

12. The method as recited in claim 11, wherein locating the optical fiber along the elongate structure comprises locating the optical fiber along a pipeline.

13. The method as recited in claim 11, wherein locating the optical fiber along the elongate structure comprises locating the optical fiber along an energy cable.

14. The method as recited in claim 11, wherein locating comprises locating the optical fiber along a pipeline positioned beneath the surface of the earth.

15. The method as recited in claim 11, wherein locating comprises locating the optical fiber along a subsea pipeline.