Julian Edward Kragh

Combination of multi-component streamer pressure and vertical particle velocity: theory and application to data

Summary In this paper, we generalize the optimal deghosting (ODG) method used for deghosting over/under data to combine pressure (P) and vertical velocity (Z) data recorded with a 4C multi-component streamer to reduce the impact of the noise on the deghosted data. The ODG approach uses pressure and velocity ghost models and the statistics of the residual noise to minimize, in a least-squares sense, the noise on the up-going/deghosted wavefield. ODG and the standard PZ summation (PZSUM) combinations are applied to pressure and velocity data recorded in the North Sea (2-D acquisition). We show that both methods attenuate the receiver ghost, fill in information at the pressure notch frequencies and that ODG has the least postcombination noise level. We also show pre- and post-stack vertical velocity data with encouraging signal-to-noise ratios. Some differences between the ODG and PZSUM combination results can be explained using the cross-line component measurement. Finally, in order to further improve the PZ deghosted data, we suggest a toolbox approach that takes advantage of both ODG and PZSUM combinations and accounts for the varying signal-to-noise ratios observed on multi-component streamer data.