Fult Detection Using the Phase Spectra from Spectral Decomposition

Lateral changes in seismic phase can be used to detect small changes in seismic arrival time and waveform shape, independent of seismic amplitudes. A method to detect subtle seismic discontinuities, as may result from small-throw faults, using spectral decomposition phase spectra and a frequency-dependent phase attribute, derived from a combination of other structural attributes, is formulated. The application of this method to 3D synthetic models shows its dependency to signal to noise ratio. The composite attribute is later applied to seismic data from the Stratton and Hitts Lake fields. Both areas show complex faulting, which is efficaciously detected by the composite attribute. This attribute appears to outperform other commonly used attributes, like coherence and curvature, in characterizing faults, both vertically and laterally. Finally, the technique is validated by observing faults detected at well log scale.