Exxon Production Research Company

Kenneth D Andersen

Richard E Duren

A method for cascading or linking seismic vibrator sweeps to form a cascaded sweep sequence. According to the method, a first cascaded sweep sequence is generated containing N sweep segments linked end-to-end. The N sweep segments are substantially identical, except that the initial phase angle of each sweep segment within the sweep sequence is progressively rotated by a constant phase increment of about 360/N degrees. A second cascaded sweep sequence is generated consisting of (i) N consecutive sweep segments linked end-to-end which correspond to said first cascaded sweep sequence and (ii) an additional sweep segment linked to the N consecutive sweep segments which is positioned and phased so as to substantially suppress harmonic ghosts during correlation. One of these cascaded sweep sequences is used for the vibrator sweep sequence and the other is used for the correlation reference sequence. Any type of sweeps may be cascaded or linked according to the method, and any amount of padding (listen time) may be inserted between the individual sweep segments.

Method for cascading sweeps for a seismic vibrator

A method of correcting a seismic pulse waveform for use in deconvolution of reflected pulse data. The source pulse waveform is measured by a hydrophone positioned vertically beneath the acoustic source. The phase error is calculated based on the depth of the source and the depth of the measuring hydrophone. The calculated error is subtracted from the phase spectrum of the measured waveform. The resulting waveform provides an accurate representation of the true far field waveform, leading to an improved expression of the waveform actually incident upon the marine floor.

Method for correcting a seismic source pulse waveform

A method for producing simple seismic wavelet shapes with minimal side lobe energy for use as reference signals for seismic vibrators is disclosed.

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Kingwood, TX, United States of America

Kenneth D Andersen