Patent ID: 9429668
Filing Date: 2016-08-30
CPC Classification: G01V

Claim Text:
1. A computer implemented method of processing a pre-stack seismic gather, in which time-spatial processing results of the pre-stack seismic gather indicate conflicting dips in subsurface formation structure, to attenuate random noise in the pre-stack seismic gather, comprising the computer implemented processing steps of: (a) assembling the time-spatial processing results of the pre-stack seismic gather in the computer to form a series of overlapping time-spatial sample windows of the pre-stack seismic gather; (b) transforming an individual one of the time-spatial sample windows of the pre-stack seismic gather into a frequency-wavenumber domain; (c) transforming the individual time-spatial sample window from the frequency-wave number domain into a Fourier-radial domain; (d) determining a map of peak values of the individual time-spatial sample window in the Fourier-radial domain; (e) transforming selected ones of the peak values of the individual time-spatial sample window in the Fourier-radial domain to indicate dominant dips in subsurface formation structure in the individual time-spatial sample window; (f) applying a median filter to the individual time-spatial window along a selected one of the indicated dominant dips in subsurface formation structure to attenuate noise from the individual time-spatial sample window; and (g) storing the remaining signal in the median filtered individual time-spatial sample window; (h) determining whether each of the indicated dominant dips in subsurface formation structure for the individual time spatial sample window has been selected; and (i) if not, selecting another indicated dominant dip in subsurface structure and repeating steps (f) and (g) along the selected another indicated dominant dip in subsurface formation structure; or (j) if so, forming a sum of the stored remaining signal of the median filtered individual time-spatial sample window along the selected dominant dips in subsurface formation structure; (k) determining whether each of the sample windows of the assembled pre-stack seismic gather have been selected; and (l) if not, selecting an additional one of the sample windows of the assembled pre-stack seismic gather and returning to step (b) for performing steps (b) through (h) on the data of the additional one of the assembled pre-stack seismic gather; or (m) is so, storing formed sums as a noise attenuated median filtered pre-stack seismic gather for each of the overlapping time-spatial sample windows; and (n) displaying the noise attenuated median filtered pre-stack seismic gather each of the overlapping sample windows for more accurate representations of the seismic survey results in areas of interest.