In cased-hole acoustic logging, estimating the formation velocity is often problematic when casing is poorly bonded with formation. The overwhelmingly large casing waves dominate the measured waveforms and overlap with the low coherence, weak formation arrival, contributing to the failure of conventional semblance processing method. To tackle this problem, we present a filter frequency semblance array waveform signal processing technique. The multiple filter technique is first used to filter the measured waveforms. We then apply the n-th root stacking method to the filtered signals. Consequently, the coherence of formation signal on the obtained three-dimensional semblance correlogram is significantly enhanced and clearly separated with the casing waves. The advantage of the new method is demonstrated using a field data example.


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  1. DziewonskiA., S.Bloch, and M.Landisman
    . [1969] A technique for the analysis of transient seismic signals. Bulletin of the Seismological Society of America, 59, 427–444.
    [Google Scholar]
  2. KimballC V, MarzettaT L
    . [1984] Semblance processing of borehole acoustic array data. Geophysics, 49(3):274–281.
    [Google Scholar]
  3. LiX.P
    . [1997]. Decomposition of vibroseis data by the multiple filter technique. Geophysics, 62, 980–991.
    [Google Scholar]
  4. McFaddenP L
    , Drummond B J and Kravis S. [1986] The n-th root stack: Theory, application, and examples. Geophysics, 51: 1879–1892
    [Google Scholar]
  5. Rao, Rama V. N. and M.Nafi Toksöz
    . [2005]. Dispersive wave analysis – Method and applications. Earth Resources Laboratory Industry Consortia, Annual Report, 2005-04.
    [Google Scholar]
  6. Smith, M.L., Sondergeld, C.H., and Norris, J.O
    . [1991] The Amoco array sonic logger. Society of Petrophysicists and Well-Log Analysts.
    [Google Scholar]
  7. TangX M and ChengC H
    . [2004] Quantitative borehole acoustic methods, Elsevier Science Publishing Company.
    [Google Scholar]
  8. TangX M and DougPatterson
    . [2005] Analyzing and Processing Acoustic Logging Data for Poorly-bonded Cased Boreholes. SPWLA 46th Annual Logging Symposium. Society of Petrophysicists and Well-Log Analysts.
    [Google Scholar]
  9. TubmanK M, ChengC H, M.Nafi Toksöz
    . [1984] Synthetic full waveform acoustic logs in cased boreholes, II—Poorly bonded casing. Geophysics, 1984, 49(7):1051–1059.
    [Google Scholar]

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