Vibroseis Deconvolution: Frequency-Domain Methods

Katherine Fiona Brittle

A vibroseis sweep is often used as a source signal for seismic exploration. During the process of vibroseis acquisition, reflections of the sweep signal are recorded with geophones. Processing techniques are required to remove the embedded vibroseis sweep from the recorded trace. Traditional vibroseis processing involves cross-correlating the trace with the sweep used in the acquisition, producing an embedded zero-phase Klauder wavelet. However, it is also possible to remove the vibroseis sweep using the method of frequency-domain sweep deconvolution (FDSD). This method utilizes the frequency domain to remove the sweep from the trace. The two sweep-deconvolution methods are compared by using synthetic traces, which include variations in sweep type, random noise and minimum-phase earth-attenuation. A comparison of the vibroseis deconvolution methods with the inclusion of Q values is provided through the use of model data and a vertical seismic profile. Further analysis is also completed with the VSP corridor stacks and with three seismic lines, determining the effects of the sweep deconvolution methods on field data. Results from the study indicate that frequencydomain sweep deconvolution is an excellent method for vibroseis deconvolution, allowing amplitude and phase information to be processed more accurately than with the method of crosscorrelation. The amplitude and phase accuracy for the final result, due to the lack of sweep dependency in FDSD, is important for further amplitude analyses and seismic interpretation techniques.