PARTICLE MOTION VECTOR MEASUREMENT IN A TOWED, MARINE SEISMIC CABLE

• US 20070195648A1
• Filed: 09/25/2006
• Published: 08/23/2007
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Reflection Marine Norge AS
• Original Assignee: WesternGeco LLC (Schlumberger NV)
• Inventors: Husom, Vidar A., Borgen, Lars, Heieren, Nils Halvor, Teigen, Oyvind
• Granted Patent: US 7,623,414 B2
• Time in Patent Office: Days
• 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

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 the particle motion sensors are 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 electromechanical system accelerometer.

12. The apparatus of claim 10, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electromechanical 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 sensing element is positioned.

16. The particle motion sensor of claim 15, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

17. The apparatus of claim 15, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

18. The apparatus of claim 15, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

19. The apparatus 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.

20. 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 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.

21. The apparatus of claim 20, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

22. The apparatus of claim 20, wherein the particle motion sensors are co-located with one of the acoustic sensors.

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

24. The apparatus of claim 20, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

25. The apparatus of claim 20, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

26. The apparatus of claim 21, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

27. The apparatus of claim 20, further comprising an acoustic source.

28. 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.

29. A streamer, comprising:

a cable;

a plurality of acoustic sensors distributed along the seismic cable; and

a micro electromechanical system accelerometer.

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 apparatus of claim 1, wherein the sensing element comprises a velocity meter or an accelerometer.

3. The apparatus of claim 2, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

4. The apparatus of claim 2, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

5. The apparatus 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.

30. The streamer of claim 29, wherein the micro electromechanical system accelerometer is co-located with one of the acoustic sensors.

31. The streamer of claim 29, wherein the micro electromechanical system accelerometer is co-located with the acoustic sensor in a single sonde.

32. The streamer of claim 29, wherein the micro electromechanical system accelerometer is a three-axis micro electromechanical system accelerometer.

33. The streamer of claim 29, wherein the micro electromechanical system accelerometer is one of three, orthogonally oriented, single axis, micro electromechanical system accelerometers.

36. The streamer of claim 29, wherein the cable comprises:

the power lead;

a command and control line; and

a data line.

37. The streamer of claim 29, wherein the streamer is a fluid-filled streamer.

38. The streamer of claim 29, wherein the streamer is a solid streamer.

39. The streamer of claim 29, wherein the streamer defines a pocket and further comprises a fluid filling the pocket in which the micro electromechanical system accelerometer is disposed.

32-1. The streamer of claim 29, wherein the micro electromechanical system accelerometer is disposed in a packing material.

35. The streamer of claim 34, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

40. A particle motion sensor for use in a streamer, the particle motion sensor comprising a micro electromechanical system accelerometer.

41. The particle motion sensor of claim 40, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

42. The particle motion sensor of claim 40, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

43. The particle motion sensor of claim 40, wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

44. The particle motion sensor of claim 40, further comprising a packing material in which the micro electromechanical system accelerometer is disposed.

45. The particle motion sensor of claim 44, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

46. The particle motion sensor of claim 40, wherein the micro electromechanical system accelerometer comprises a monocrystalline semiconductor device.

47. The particle motion sensor of claim 40, wherein the micro electromechanical system accelerometer comprises an inertial mass on the free end of a cantilevered beam.

48. 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 comprises micro electromechanical system.

49. The apparatus of claim 48, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

50. The apparatus of claim 48, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

51. The apparatus of claim 48, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

52. The apparatus of claim 48, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

53. 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.

54. The apparatus of claim 53, wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center.

55. The apparatus of claim 53, wherein the sensing element comprises a velocity meter or an accelerometer.

56. The apparatus of claim 55, wherein the accelerometer comprises a three-axis, micro electromechanical system accelerometer.

57. The apparatus of claim 55, wherein the sensing element comprises three single-axis, orthogonally oriented, micro electromechanical system accelerometers.

58. The apparatus of claim 53, wherein the packing material comprises:

a fluid;

a deformable, expanded foam body;

a polymer with added micro-spheres;

or

a low density plastic.

59. The streamer of claim 53, wherein the cable comprises:

the power lead;

a command and control line; and

a data line.