Nonlinear seismic trace interpolation

Abstract

The nonlinear correlation technique has been used to guide a seismic trace interpolant to fill gaps in seismic surveys, replace noisy traces, and produce evenly spaced arrays. Given an initial alignment (NMO correction for prestack data and manually inserted correlation lines for post‐stack data), the correlation aligns corresponding features between adjacent seismic traces and quantifies the traveltime difference between the traces on a point‐for‐point basis. This information is used to construct synthetic (interpolated) traces, at any arbitrary distance between the correlated traces, which preserve dip and amplitude changes of the individual reflectors, assuming that such dip and amplitude changes occur linearly (or some other specified functional form) between the correlated traces. The technique is applied to a 48-channel, NMO corrected, CDP gather and to a stacked seismic section to demonstrate its use, sensitivities, and limitations in processing and geologic interpretation studies. Traces synthesized in the CDP gather filling an artificial gap 0.85 km wide reproduce the true traces from the gap with good fidelity (correlation coefficients between the synthetic and real traces average ≳0.85). In another example, ∼85 percent of the variance of the original 48-channel CDP gather is recovered through interpolation by using only 16 channels. A stacked section, with true trace spacing of 25 m, was decimated to 100 m trace spacing, then interpolated to restore the original 25 m spacing. The interpolated traces reproduce the real traces with correlations of ⩾0.95, thus recovering ⩾90 percent of the variance of the original section.