Particle motion vector measurement in a towed, marine seismic cable

• US 7,623,414 B2
• Filed: 09/25/2006
• Issued: 11/24/2009
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Reflection Marine Norge AS
• Original Assignee: WesternGeco LLC
• Inventors: Boergen, Lars, Teigen, Oyvind, Traetten, Oeystein, Husom, Vidar A., Heieren, Nils Halvor
• Primary Examiner(s): PIHULIC, DANIEL T
• Application Number:
  US11/534,969
• Publication Number:
  US 20070195648A1
• Time in Patent Office: 1,156 Days
• Field of Search: 367/24, 367/99, 367/129, 367/130, 367/153, 367171-173, 367/178, 367/188, 181/10, 181/12, 181/110, 181/112
• US Class Current: 367/178
• CPC Class Codes: G01V 1/181 Geophones
• CPC Class Codes: G01V 1/20 Arrangements of receiving elements, e.g. geophone pattern
• CPC Class Codes: G01V 1/201 Constructional details of seismic cables, e.g. streamers integrated optoseismic systems G01V1/226; line connectors in general H01R, transducer mountings in general G10K11/004

Abstract

A particle motion sensor, includes: a sensing element capable of sensing a particle motion vector from a change in position thereof, and a packing material in which the sensing element is positioned, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center. An apparatus includes a streamer; a plurality of acoustic sensors distributed along the streamer; and a plurality of particle motion sensors distributed along the streamer, at least one particle motion sensor being symmetric about its longitudinal axis and having a center of gravity coincident with its volumetric center.

Claims

1. A particle motion sensor, comprising:

a sensing element capable of sensing a particle motion vector from a change in position thereof, and

a packing material in which the sensing element is positioned;

wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

2. The particle motion sensor of claim 1, wherein the sensing element comprises a velocity meter or an accelerometer.

3. The particle motion sensor of claim 2, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

4. The particle motion sensor of claim 2, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

5. The particle motion sensor of claim 1, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

6. An apparatus comprising:

a streamer;

a plurality of acoustic sensors distributed along the streamer; and

a plurality of particle motion sensors distributed along the streamer, at least one particle motion sensor being symmetric about its longitudinal axis and having a center of gravity coincident with its volumetric center.

7. The apparatus of claim 6, wherein the particle motion sensor includes:

a sensing element electrically communicating with, but de-coupled from, the streamer and capable of sensing a particle motion vector from a change in position thereof; and

a packing material in which the sensing element is positioned.

8. The apparatus of claim 6, wherein each of the particle motion sensors is co-located with one of the acoustic sensors.

9. The apparatus of claim 6, wherein the acoustic sensors comprise a plurality of hydrophones.

10. The apparatus of claim 7, wherein the sensing element comprises a velocity meter or an accelerometer.

11. The apparatus of claim 10, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

12. The apparatus of claim 10, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

13. The apparatus of claim 7, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

14. The apparatus of claim 6, further comprising an acoustic source.

15. A particle motion sensor, comprising:

an accelerometer capable of sensing a particle motion vector from a change in position thereof, and

a packing material in which the accelerometer is positioned;

wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

16. The particle motion sensor of claim 15, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electro- mechanical system accelerometers.

17. The particle motion sensor of claim 15, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

25. The particle motion sensor of claim 15, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

18. An apparatus comprising:

a streamer;

a plurality of acoustic sensors distributed along the streamer; and

a plurality of particle motion sensors distributed along the streamer, at least one particle motion sensor being symmetric about its longitudinal axis, having a center of gravity coincident with its volumetric center, and including;

an accelerometer capable of sensing a particle motion vector from a change in position thereof; and

a packing material in which the sensing element is positioned.

19. The apparatus of claim 18, wherein each of the particle motion sensors is co-located with one of the acoustic sensors.

20. The apparatus of claim 18, wherein the acoustic sensors comprise a plurality of hydrophones.

21. The apparatus of claim 18, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

22. The apparatus of claim 18, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

23. The apparatus of claim 18, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

24. The apparatus of claim 18, further comprising an acoustic source.

26. A particle motion sensor for use in a streamer, the particle motion sensor comprising:

a packing material; and

a micro electro-mechanical system accelerometer disposed within the packing material;

wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

27. The particle motion sensor of claim 26, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

28. The particle motion sensor of claim 26, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

29. The particle motion sensor of claim 26, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

30. The particle motion sensor of claim 26, wherein the micro electro-mechanical system accelerometer comprises a monocrystalline semiconductor device.

31. The particle motion sensor of claim 26, wherein the micro electro-mechanical system accelerometer comprises an inertial mass on the free end of a cantilevered beam.

32. A particle motion sensor for measuring seismic wavefield in water, comprising:

a sensing element capable of sensing a particle motion vector from a change in position thereof; and

a packing material in which the sensing element is positioned;

wherein the sensing element is a velocity meter or an accelerometer comprising a micro electro-mechanical system and the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

33. The particle motion sensor of claim 32, wherein the sensing element comprises a three-axis, micro electro-mechanical system accelerometer.

34. The particle motion sensor of claim 32, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

35. The particle motion sensor of claim 32, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

36. A particle motion sensor, comprising:

a packing material;

a plurality of components including at least one sensing element, the components being disposed in the packing material in a manner defining an aperture through which a cable may extend;

wherein the sensing element is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

37. The particle motion sensor of claim 36, wherein the sensing element comprises a velocity meter or an accelerometer.

38. The particle motion sensor of claim 37, wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.

39. The particle motion sensor of claim 37, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers.

40. The particle motion sensor of claim 36, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

41. The particle motion sensor of claim 36, wherein the cable comprises:

a power lead;

a command and control line; and

a date line.