Particle motion vector measurement in a towed, marine seismic cable

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.

1 - 14 . (canceled) 
   
   
       15 . A particle motion sensor, comprising:
 a micro electro-mechanical system 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 . (canceled) 
   
   
       17 . The particle motion sensor of  claim 15 , wherein the micro electro-mechanical system accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       18 . The particle motion sensor of  claim 15 , wherein the micro electro-mechanical system accelerometer comprises one of three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers. 
   
   
       19 . 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.   
   
   
       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:
 a micro electro-mechanical system 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 . (canceled) 
   
   
       22 . The apparatus of  claim 20 , wherein each of the particle motion sensors is 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 micro electro-mechanical system accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       25 . The apparatus of  claim 20 , wherein the micro electro-mechanical system accelerometer comprises one of three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers. 
   
   
       26 . The apparatus of  claim 20 , 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 . (canceled) 
   
   
       29 . A streamer, comprising:
 a seismic streamer cable;   a plurality of seismic sensors distributed along the seismic cable;   a packing material filling voids in the seismic streamer cable; and   a micro electro-mechanical system accelerometer disposed in the packing material.   
   
   
       30 . The streamer of  claim 29 , wherein the micro electro-mechanical system accelerometer is co-located with one of the seismic sensors. 
   
   
       31 . The streamer of  claim 29 , wherein the micro electro-mechanical system accelerometer is co-located with the seismic sensor in a single sonde. 
   
   
       32 . The streamer of  claim 29 , wherein the micro electro-mechanical system accelerometer is a three-axis micro electro-mechanical system accelerometer. 
   
   
       33 . The streamer of  claim 29 , wherein the micro electro-mechanical system accelerometer is one of three, orthogonally oriented, single axis, micro electro-mechanical system accelerometers. 
   
   
       34 . (canceled) 
   
   
       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.   
   
   
       36 . The streamer of  claim 29 , wherein the cable comprises:
 a 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 electro-mechanical system accelerometer is disposed. 
   
   
       40 . 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.   
   
   
       41 . (canceled) 
   
   
       42 . The particle motion sensor of  claim 40 , wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       43 . The particle motion sensor of  claim 40 , wherein the accelerometer comprises one of three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers. 
   
   
       44 . (canceled) 
   
   
       45 . The particle motion sensor of  claim 40 , 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 electro-mechanical system accelerometer comprises a monocrystalline semiconductor device. 
   
   
       47 . The particle motion sensor of  claim 40 , wherein the micro electro-mechanical 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 comprising a micro electro-mechanical system.   
   
   
       49 . (canceled) 
   
   
       50 . The particle motion sensor of  claim 48 , wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       51 . The particle motion sensor of  claim 48 , wherein the sensing element comprises a three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers. 
   
   
       52 . The particle motion sensor 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 . (canceled) 
   
   
       55 . The particle motion sensor of  claim 53 , wherein the sensing element comprises a velocity meter or an accelerometer. 
   
   
       56 . The particle motion sensor of  claim 55 , wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       57 . The particle motion sensor of  claim 55 , wherein the sensing element comprises three single-axis, orthogonally oriented, micro electro-mechanical system accelerometers. 
   
   
       58 . The particle motion sensor 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 particle motion sensor of  claim 53 , wherein the cable comprises:
 a power lead;   a command and control line; and   a data line.   
   
   
       60 . A particle motion sensor, comprising:
 a sensing element capable of electrically communicating with, while structurally de-coupled from, a streamer and capable of sensing a particle motion vector from a change in position thereof, and   a fluid packing material in which the sensing element is positioned.   
   
   
       61 . The particle motion sensor of  claim 60 , wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center. 
   
   
       62 . The particle motion sensor of  claim 60 , wherein the sensing element comprises an accelerometer. 
   
   
       63 . The particle motion sensor of  claim 62 , wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer. 
   
   
       64 . 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:
 a sensing element capable of electrically communicating with, while de-coupled from, a streamer and capable of sensing a particle motion vector from a change in position thereof; and 
 a fluid packing material in which the sensing element is positioned. 
   
   
   
       65 . The apparatus of  claim 64 , wherein the particle motion sensor is symmetric about its longitudinal axis and has a center of gravity coincident with its volumetric center. 
   
   
       66 . The apparatus of  claim 64 , wherein each of the particle motion sensors is co-located with one of the acoustic sensors. 
   
   
       67 . The apparatus of  claim 64 , wherein the acoustic sensors comprise a plurality of hydrophones. 
   
   
       68 . The particle motion sensor of  claim 64 , wherein the sensing element comprises an accelerometer. 
   
   
       69 . The apparatus of  claim 68 , wherein the accelerometer comprises a three-axis, micro electro-mechanical system accelerometer.