Real-Time Monitoring of a Metal Surface

• US 20150285705A1
• Filed: 03/16/2015
• Published: 10/08/2015
• Est. Priority Date: 04/04/2014
• Status: Active Grant

• Current Assignee: Amit Kumar, Ramani V. Reddy
• Original Assignee: Amit Kumar, Ramani V. Reddy
• Inventors: Kumar, Amit, Reddy, Ramani V.
• Granted Patent: US 10,031,044 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01M 11/085 the optical fiber being on or near the surface of the DUT
• CPC Class Codes: G01M 5/0025 of elongated objects, e.g. pipes, masts, towers or railways G01M5/0058 takes precedence
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00
• CPC Class Codes: G01M 5/0091 by using electromagnetic excitation or detection

Abstract

Methods and systems for providing real-time monitoring of a metal surface are provided herein. The system includes a fiber-optic cable disposed alongside a length of a wall that includes the metal surface. A laser source is attached to the fiber-optic cable to transmit light through the fiber-optic cable. An acoustic source is configured to generate acoustic signals in the metal surface, wherein the acoustic signals interact with the fiber-optic cable and influence characteristics of the light. A receiver is attached to the fiber-optic cable to detect the light. The system also includes a signal processing unit configured to determine a location of a change in the metal surface based on changes in the characteristics of the light.

Claims

1. A system for real-time monitoring of a metal surface, comprising:

a fiber-optic cable disposed alongside a length of a wall comprising the metal surface;

a laser source attached to the fiber-optic cable, wherein the laser source is configured to transmit light through the fiber-optic cable;

an acoustic source configured to generate acoustic signals in the metal surface, wherein the acoustic signals interact with the fiber-optic cable and influence characteristics of the light;

a receiver attached to the fiber-optic cable, wherein the receiver is configured to detect the light; and

a signal processing unit configured to determine a location of a change in the metal surface based on changes in the characteristics of the light.

2. The system of claim 1, wherein the change influencing the characteristics of the light comprises an intrusion which is caused by erosion of the metal surface.

3. The system of claim 1, wherein the change influencing the characteristics of the light comprises an intrusion which is caused by corrosion of the metal surface.

4. The system of claim 1 wherein the fiber-optic cable extends alongside a substantially full length of the wall, wherein the metal surface comprises an external surface of a pipeline or an internal surface of a pipeline.

5. The system of claim 1, wherein the system is configured to continue to monitor the metal surface if a portion of the fiber-optic cable is damaged.

6. The system of claim 1, wherein the fiber-optic cable comprises a plurality of fiber-optic cables, and wherein the number of the fiber-optic cables is correlative with dimensions of the metal surface and the sensitivity of the fiber-optic cables.

8. The system of claim 1, wherein the metal surface comprises a surface of a metal pipeline, metal vessel, or metal container.

9. The system of claim 1, wherein the laser source comprises a laser diode, a light-emitting diode, a modulator, or any combinations thereof.

10. The system of claim 1, wherein the acoustic source comprises a moving source.

11. The system of claim 1, wherein the receiver comprises a photodiode, a phototransistor, a photomultipler tube, or any combinations thereof.

12. The system of claim 1, wherein the signal processing unit comprises a phase locked loop.

13. The system of claim 3, wherein the change in the metal surface additionally comprises physical damage.

7. The system of claim 7, wherein the plurality of fiber-optic cables comprises a first fiber-optic cable that is pressure-sensitive, a second fiber-optic cable that is pressure-insensitive.

14. A system for real-time monitoring of a pipe that conveys hydrocarbons, comprising:

a fiber-optic cable disposed alongside a pipe wall of a pipe that conveys hydrocarbons;

a laser source attached to the fiber-optic cable, wherein the laser source is configured to transmit a light pulse through the fiber-optic cable;

an acoustic source configured to generate acoustic signals in the pipe wall, wherein the acoustic signals interact with the fiber-optic cable and influence characteristics of the light pulse in the fiber-optic cable;

a receiver attached to the fiber-optic cable, wherein the receiver is configured to detect the light pulse; and

a signal processing unit configured to determine a location of an intrusion in the pipe wall based on changes in the characteristics of the light pulse.

15. The system of claim 14, wherein the intrusion comprises corrosion of the pipe wall.

16. The system of claim 14, wherein the intrusion comprises erosion of the pipe wall.

17. The system of claim 14, wherein the fiber-optic cable comprises a plurality of fiber-optic cables.

18. The system of claim 17, wherein the plurality of fiber-optic cables comprises a pressure-sensitive fiber-optic cable and a pressure-insensitive fiber-optic cable.

19. The system of claim 14, wherein the acoustic source comprises a moving source in a fluid-flow path of the pipe.

20. The system of claim 14, wherein the acoustic signals comprise sound waves, pressure waves, or both.

21. The system of claim 14, wherein the acoustic source comprises a fixed source coupled to the pipe.

22. The system of claim 14, comprising a plurality of fiber-optic cables, each disposed along a segment of the pipe wall, wherein damage to a fiber-optic cable does not stop monitoring of the pipe wall by the other fiber-optic cables in the plurality of fiber-optic cables.

23. The system of claim 14, comprising a plurality of laser sources and a plurality of receivers disposed along the pipe.

24. A method for monitoring changes in a wall of a pipe, comprising;

disposing a fiber-optic cable alongside a length of the pipe wall;

attaching a light source to the fiber-optic cable to transmit light through the fiber-optic cable;

providing an acoustic source adjacent to, or within, the pipe to generate acoustic signals within the pipe wall that interact with the fiber-optic cable to influence characteristics of the light pulse;

attaching a receiver to the fiber-optic cable to detect the light from the fiber-optic cable;

coupling a signal processing unit to the receiver, wherein the signal processing unit determines changes between the light originating from the light source with the light detected at the receiver; and

locating an intrusion on the pipe wall based, at least in part, on the changes.

25. The method of claim 24, comprising installing the fiber-optic cable alongside a substantially full length of the pipe.

26. The method of claim 24, comprising attaching a plurality of laser sources and a plurality of receivers along the pipe.