Beat phenomenon in shallow water seismic data and its lag-log domain suppression

Ringing and bubble noises common in shallow water seismic exploration may lead to strong low-frequency reverberations with periodic increase and decrease in envelope amplitude in seismic data. Conventional deterministic deconvolution using far-field wavelets and predictive deconvolution do not have good performance for suppressing such noises. The Ricker-compliant deconvolution method proposed by Claerbout is a paradigm for suppressing bubble effects in offshore seismic data. Based on the Claerbout's theory, this paper proposes a lag-log domain filter to suppress low-frequency reverberations in beat envelope amplitude, redefines the medium-time-delay signal in the lag-log domain, and divides the data into small-lag signals, medium-lag signals and large-lag signals. According to different signal distributions, a Kolmogorov filter is constructed to remove medium- and large-lag signals, or reverberations and bubbles. Testing results show that lag-log domain filtering gets a good result in suppressing low-frequency reverberations in beat envelope. A comparative study of real data processing shows that lag-log domain filtering performs better than several other methods in the suppression of low-frequency reverberations.