Chevron U.s.a. Inc.

Bones, Dennis G.

Louie, Kendal Bong Hu

Herkenhoff, E. Frederic

E Frederic Herkenhoff

Richard B Alford

Joseph Paul Stefani

Harry L Martin

Dennis G Bones

A system for and computer implemented method for transforming seismic trace information includes obtaining seismic trace information for each trace, the seismic trace information including shot to receiver offset and the vertical velocity of at least one subsurface primary reflector and including respective information resulting from near-surface layering and velocity effects and relating to the primary reflector, reversibly transforming seismic trace information from each non-zero offset trace such that the respective information resulting from the near-surface effects at each non-zero offset position is moved in a time dimension such that they become effectively periodic with respect to respective primary reflector information and in accordance with a periodicity for a zero offset trace at the same surface location, filtering the transformed seismic trace information to remove at least a portion of the information resulting from near-surface effects, and inverting the reversible transforming.

System and method for compensating time and offset varying near-surface effects in seismic data background

A method for obtaining seismic data is disclosed. A constellation of seismic energy sources is translated along a survey path. The seismic energy sources include a reference energy source and a satellite energy source. The reference energy source is activated and the satellite energy source is activated at a time delay relative to the activation of the reference energy source. This is repeated at each of the spaced apart activation locations along the survey path to generate a series of superposed wavefields. The time delay is varied between each of the spaced apart activation locations. Seismic data processing comprises sorting the traces into a common geometry domain and replicating the traces into multiple datasets associated with each particular energy source. Each trace is time adjusted in each replicated dataset in the common-geometry domain using the time delays associated with each particular source. This result in signals generated from that particular energy source being generally coherent while rendering signals from the other energy source is generally incoherent. The coherent and incoherent signals are then filtered to attenuate incoherent signals.

Methods for acquiring and processing seismic data from quasi-simultaneously activated translating energy sources

The present invention provides a method and apparatus for arriving at true relative amplitude destretched seismic traces from stretched seismic traces. The method compensates for offset varying reflection interference effects due to normal moveout. Stretch factors &#x3b2; and also input spectra are determined for NMOR stretched seismic traces. Estimates are then made of stretched wavelet spectra from the input spectra. A destretched wavelet spectra is then obtained. Shaping correction factors are determined by taking the ratio of the destretched wavelet spectra to the stretched wavelet spectra and are applied to the input spectra of the stretched traces to arrive at a destretched trace spectra. True relative amplitude scaling factors are computed by taking the ratio of a true relative amplitude property of the destretched wavelet spectra to a corresponding true relative amplitude property of the stretched wavelet spectra. Finally, the true relative amplitude scaling factors are applied to the destretched trace spectra to arrive at true relative amplitude destretched seismic traces.

Method and apparatus for true relative amplitude correction of seismic data for normal moveout stretch effects

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Orinda, CA, United States of America

E Frederic Herkenhoff