1887

Abstract

Summary

The importance of low-frequency acquisition is widely recognized as it contributes to illumination of deeper targets and estimation of quantitative properties by the use of full waveform inversion. We introduce an approach of low-frequency acquisition using half-cycle pseudorandom sweeps. The waveform is characterized by continuous half-cycle sine curves with constant frequency (carrier frequency), which polarity changes randomly. Auto-correlation of the half-cycle pseudorandom sweep is close to side-lobe free delta-function, which makes it possible to obtain broad-band seismic data. We performed a field test for a crosshole seismic survey using piezoelectric source with various carrier frequencies. Each pseudorandom sweep has the same number of “half-cycles”, and therefore, the total sweep time is shorter with increasing carrier frequency. The field results demonstrated that low frequency component is not dependent on the carrier frequency, although high frequency component increases with it. Thus, half-cycle pseudorandom with higher carrier frequency can provide broadband seismic data with shorter acquisition time, which is related to flat frequency property of the piezoelectric source. This approach should provide low-frequency data acquisition from piezoelectric or other high-frequency instruments and may be a significant contribution to low-frequency data acquisition.

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/content/papers/10.3997/2214-4609.201601603
2016-05-30
2024-03-29
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References

  1. Dean, T.
    [2012] Establishing the limits of vibrator performance - experiments with pseudorandom sweeps. SEG Technical Program Expanded Abstracts 2012, 1–5.
    [Google Scholar]
  2. Dean, T., Tulett, J., Lane, D. and Puckett, K.
    [2015] Surface and downhole recording of pseudorandom vibroseis sweeps. SEG Technical Program Expanded Abstracts 2015, 191–195.
    [Google Scholar]
  3. Plessix, R.E., Baeten, G., Maag, J. W., Klaassen, M., RujieZ. and Zhifei, T.
    [2010] Application of acoustic full waveform inversion to a low-frequency large-offset land data set. SEG Technical Program Expanded Abstracts 2010, 930–934.
    [Google Scholar]
  4. Sakakibara, J., Tago, A., Nakamura, Y., Kunishi, Y. and Takanashi, M.
    [2015] Monitoring of injected micro-bubble-water by P-wave attenuation tomography. The 133rd SEGJ conference.
    [Google Scholar]
  5. Wei, Z., and T. F.Phillips
    [2013] On the generation of low frequencies with modern seismic vibrators. GEOPYSICS, Vol. 78, WA91–WA97.
    [Google Scholar]
  6. Wischmeyer, C.R.
    [1966] Method and apparatus for continuous wave seismic prospecting. U.S. Patent 3, 234, 504.
    [Google Scholar]
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