Chevron U.s.a. Inc.

E Fredrick Herkenhoff

Dennis George Bones

Kendall Bong Hu Louie

Harry L Martin

Jonathan D Cocker

A method for enhancing signal-to-noise (S/N) ratio of seismic data is presented. An ensemble of input traces is decomposed into a plurality of frequency bands of traces. Trace and signal power and then a maximum allowable signal-to-noise ratio are estimated for each frequency band. Weights are calculated which are functions of the inverse noise power or rms. The amplitudes in each of the traces are reformed using a fitting function which utilizes the estimated weights to create true relative amplitude signal enhanced traces. The weighting function has data adaptive parameters which can be changed to accommodate noise characteristics such coherency, incoherency, Gaussian and non-Gaussian distributions, etc. The method may be applied across many different coordinate systems. The method may be applied iteratively to seismic data to shape the noise distribution of the seismic data.

Method for signal-to-noise ratio enhancement of seismic data using frequency dependent true relative amplitude noise attenuation

A method for processing seismic traces to provide enhanced signal-to-noise ratio in seismic data is provided. A seismic survey of traces is obtained which has been collected over an areal region containing a grid of nodes. A rolling supergather aperture is used to select a subregion containing a working subset of traces. A model subset of traces is selected from proximate the center of the working subregion. The model subset of traces are composited to form a model trace. A modified subset of traces is created by comparing the individual traces with the model trace using an alignment technique, which is preferably a time varying trim statics technique. These modified subsets of traces may then be composited into a reduced set of enhanced seismic traces having enhanced signal-to-noise ratio relative to the original seismic traces. The rolling supergather aperture is then incrementally moved until traces from all over the areal region are chosen and enhanced subsets of seismic traces have been assembled into a set of seismic data having enhanced signal-to-noise ratio.

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Orinda, CA, United States of America

E Fredrick Herkenhoff