Enhancing interpretability of seismic data with spectral decomposition phase components

Abstract

Summary Stratigraphic interpretation of seismic data requires careful interpretation of the amplitude, phase and frequency so as to gauge the geologic subsurface detail. Sometimes the interpretation of the changes in amplitudes is not easy and the equivalent phase is difficult to comprehend. In such cases seismic attributes are utilized to provide additional information that could aid the interpretation. One of the earliest set of ‘instantaneous’ attributes was based on complex trace analysis, and instantaneous phase has been used for interpretation of stratigraphic features such as pinchouts and discontinuities as well as fault edges. In this study, we demonstrate that the interpretability of seismic data can be enhanced with the use of spectral phase components derived during spectral decomposition. As there are different methods for decomposing seismic data into its component frequencies and phase within the seismic bandwidth, we consider two of the common methods in our analysis here, namely the continuous wavelet transform and the matching pursuit methods. We also show that the principal component analysis of spectral magnitude and phase components yields additional insight into the data. The first principal component ‘churned’ out of the phase components shows clarity in the features of interest and compares favourably with the discontinuity attributes commonly used for the purpose.