HR: 1340h
AN: S43B-1301    [Abstracts]
TI: Extraction of P and S Wave Propagations and Measurement of Shear-Wave Splitting From Noise Data
AU: * Miyazawa, M
EM: linen@eqh.dpri.kyoto-u.ac.jp
AF: Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto, 611-0011, Japan
AU: Snieder, R
EM: rsnieder@mines.edu
AF: Center for Wave Phenomena, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401-1887, United States
AU: Venkataraman, A
EM: anupama.venkataraman@exxonmobil.com
AF: ExxonMobil Upstream Research Company, PO Box 2189, URC-GW3-917A, Houston, TX 77252-2189, United States
AB: We extracted downward propagating P and S waves from industrial noise propagating down a borehole at Cold Lake, Alberta, Canada and also found shear-wave splitting from these measurements. The continuous seismic data are recorded at 8 sensors along a down-hole well during steam injections into 420 to 470 m-deep oil reservoir. We used cross-correlation of the waveforms observed at the bottom sensor (depth = 370m) and other 7 sensors (depths = 190, 210, 235, 262, 287, 307, 340 m) to extract the Green's function that accounts for wave propagation between sensors. Fast high-frequency and slow low-frequency signals propagating vertically from the surface to the bottom are found for the vertical and horizontal components of the wave motion, which are identified with P and S waves, respectively. The detected signals agree well with the travel time curves calculated for the seismic velocity model obtained by travel time tomography. The fastest S wave, polarized in the northeast-southwest direction, is about 1.9% faster than the slowest S wave polarized in the northwest- southeast direction. The direction of polarization of the fast S wave is rotated by about 20 degrees in clock-wise direction from the maximum principal stress axis as estimated from the regional stress field. This study demonstrates the useful application of seismic interferometry to field data to determine structural parameters.
DE: 7200 SEISMOLOGY
DE: 7203 Body waves
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting