System and method for subsea inspection

Patent metadata

Field	Value
Publication number	US-9903839-B2
Application number	US-201314409993-A
Country	US
Kind code	B2
Filing date	Jun 21, 2013
Priority date	Jun 21, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Embodiments include subsea ultrasonic inspection systems employing electromagnetic acoustic transducers (EMATs) to inspect subsea objects, such as subsea tubular items, conduit, piping, pipelines, risers, vessels, structures, and so forth.

First claim

What is claimed is:

1. An electromagnetic acoustic transducer for inspecting a subsea object, comprising:
a magnetic component to generate a magnetic field in a subsea object;
a coil to induce eddy currents on a surface of the subsea object;
sea water flow-through holes to funnel sea water adjacent the coil; and
a substantially non-conductive wear plate, wherein the non-conductive wear plate comprises a non-metallic material, disposed on a bottom portion of the electromagnetic acoustic transducer.

2. The electromagnetic acoustic transducer of claim 1 , comprising protective slide plates disposed on a bottom portion of the electromagnetic acoustic transducer.

3. The electromagnetic acoustic transducer of claim 1 , comprising a metal backing on the coil.

4. The electromagnetic acoustic transducer of claim 3 , wherein the metal backing comprises a copper backing.

5. The electromagnetic acoustic transducer of claim 1 , comprising a cart housing the electromagnetic acoustic transducer.

6. The electromagnetic acoustic transducer of claim 1 , wherein the electromagnetic acoustic transducer is disposed in a carriage.

7. The electromagnetic acoustic transducer of claim 1 , wherein the electromagnetic acoustic transducer is a shear horizontal wave transducer.

8. The electromagnetic acoustic transducer of claim 1 , wherein the electromagnetic acoustic transducer is configured to induce Lamb waves in the subsea object, the Lamb waves being optimized such that 70% of more of the Lamb waves are tangential.

9. The electromagnetic acoustic transducer of claim 8 , wherein 90% or more of the Lamb waves are tangential.

10. An electromagnetic acoustic transducer scanner assembly for inspecting a subsea object, comprising:
a carriage;
a control cable or tether to provide communication with a control point above water or a remote operated vehicle;
a first transducer cart comprising an electromagnetic acoustic transducer transmitter wherein the electromagnetic acoustic transducer transmitter comprises a magnet, electromagnetic acoustic transducer coil, sea water flow-through holes to funnel sea water adjacent the coil, and a non-metallic wear plate; and
a second transducer cart comprising an electromagnetic acoustic transducer receiver, wherein the electromagnetic acoustic transducer receiver comprises a magnet, electromagnetic acoustic transducer coil, sea water flow-through holes to funnel sea water adjacent the coil, and a non-metallic wear plate, wherein the first and second transducer carts are each disposed in the carriage and configured for use in subsea inspection.

11. The electromagnetic acoustic transducer scanner assembly of claim 10 , comprising protective slide plates on the first and second transducer carts.

12. The electromagnetic acoustic transducer scanner assembly of claim 10 , comprising a metal backing on each coil.

13. The electromagnetic acoustic transducer scanner assembly of claim 12 , wherein the metal backing comprises a copper backing.

14. The electromagnetic acoustic transducer scanner assembly of claim 10 , wherein the electromagnetic acoustic transducer transmitter is a shear horizontal wave transducer.

15. The electromagnetic acoustic transducer of claim 10 , wherein the electromagnetic acoustic transducer transmitter is configured to induce Lamb waves in the subsea object, the Lamb waves being optimized such that 70% of more of the Lamb waves are tangential.

16. A method of operating a subsea electromagnetic acoustic transducer scanner assembly to inspect a subsea object, the method comprising:
deploying the electromagnetic acoustic transducer scanner assembly subsea, wherein the electromagnetic acoustic transducer scanner assembly comprises a first transducer cart comprising an electromagnetic acoustic transducer transmitter, wherein the electromagnetic acoustic transducer transmitter comprises a magnet, electromagnetic acoustic transducer coil, sea water flow-through holes to funnel sea water adjacent the coil, and a non-metallic wear plate, and a second transducer cart comprising an electromagnetic acoustic transducer receiver, wherein the electromagnetic acoustic transducer receiver comprises a magnet, electromagnetic acoustic transducer coil, sea water flow-through holes to funnel sea water adjacent the coil, and a non-metallic wear plate;
driving the electromagnetic acoustic transducer scanner assembly along the subsea object to be inspected;
instructing remotely the electromagnetic acoustic transducer scanner assembly to inspect the subsea object;
surrounding the coils with seawater to promote electrical grounding, wherein the seawater entering through the flow-through holes shields the coils from background interference;
collecting subsea inspection data of the subsea object via the electromagnetic acoustic transducer scanner assembly; and
communicating the data to the surface of the water.

17. The method of claim 16 , comprising routing seawater adjacent a sensor of the electromagnetic acoustic transducer scanner assembly.

18. The method of claim 16 , wherein the deploying the electromagnetic acoustic transducer scanner assembly comprises using a remote operated vehicle.

Assignees

• Oceaneering Int Inc

Inventors

• Adams Mark Alan
• Boyle John Joseph

Classifications

• G01N2291/0422

  Shear waves, transverse waves, horizontally polarised waves · CPC title

• G01N29/041

  on the surface of the material, e.g. using Lamb, Rayleigh or shear waves · CPC title

• G01N29/2412 Primary

  using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]; (investigating the presence of flaws using eddy currents G01N27/90, magnetostrictive transducers B06B1/08, measuring magnetostrictive properties G01R33/18) · CPC title

• G01N29/225

  Supports, positioning or alignment in moving situation · CPC title

• G01N2291/0427

  Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever · CPC title