Spectral Decomposition provides a means to use seismic data and the discrete Fourier transform to image and map temporal bed thickness and geologic dis-continuities in 3D seismic surveys. The concept behind spectral decomposition is that a reflection from a thin bed has a characteristic expression in the frequency domain that indicates temporal bed thickness.
Two methods are supported to output spectral amplitudes. In the ‘Frequency Slice’ method, panels of amplitude spectra at specific frequencies are output. In the ‘A Frequency Spectrum’ method, a frequency spectrum at a specific horizon or time is computed.
An additional tool ‘Spectral Decomposition Scaling’ should be used to apply a spectral compensation factor to each frequency slice. The goal is to balance the wavelet spectrum by equalizing each frequency slice according to its average amplitude.
Several examples are courtesy of True Oil Company, LLC, Casper, Wyoming.
Spectral Decomposition at a specfic frequency on a depth slice.
Seismic amplitude at depth slice.
Synthetic channel and Spectral Decomposition response.