Chevron Research Company

Francis Muir

Raymond Andrew Ergas

The disclosed invention is a method of seismic exploration using non-impulsive vibratory sources activated by filtered stationary, Gaussian codes. The method adds a distortion-free quality to the full-waveform seismic records.

Seismic exploration using non-impulsive vibratory sources activated by

The disclosed invention is a method of seismic exploration using non-impulsive vibratory sources activated by stationary, Gaussian codes in urban areas. The method adds a distortion-free quality to the full-waveform seismic records.

The disclosed invention is a method of seismic exploration using non-impulsive vibratory sources activated by stationary, Gaussian codes in a wellbore environment. The method adds a distortion-free quality to the full-waveform seismic records.

A method is disclosed for determining if sign-clipped variations of full-waveform traces can be used in subsequent cross-correlation processing without undue hardship. In accordance with one aspect, the present invention examines skewness of the amplitude spectrum of the full waveform. If the former significantly differs from conventional Gaussian distribution over the frequency range of interest, i.e., the amplitude spectrum is non-Gaussian, sign-clipped versions thereof can be used in subsequent cross-correlation processing without undue loss in processing accuracy. In another aspect, the present invention is used to edit a series of traces, one at a time, gathered by a large multichannel collection system. In this aspect, the different spectral noise estimates, including cross-correlation estimates generated from sign-clipped versions of the full-waveform traces, are advantageously used.

Robust estimation method for determining when subsequent data processing

The disclosed invention is a method of seismic exploration using non-impulsive vibratory sources activated by stationary, Gaussian codes. The method has the channel-capacity economy of sign-bit recording and the distortion-free quality of full-waveform seismic records, even through zero memory, non-linear representations ('ZNL's') are employed either during the collection or the processing steps that produce such final records. As a result, stratigraphic facies can be both economically and surprisingly indicated.

The disclosed invention is a method of seismic exploration using vibratory sources activated by stationary, Gaussian codes. The method has the channel-capacity economy of sign-bit recording, at both the sources and receivers, without the sacrifice of any desired seismic information in the final processed records. Even the relative amplitudes between traces may be recovered in the method.

Growing community of inventors

Laguna Niguel, CA, United States of America

Francis Muir