Broadband Data from Flat Streamers: Considerations for Acquisition and Processing

Abstract

Broadband acquisition aims to improve the bandwidth of seismic data, which in practice means extending the low-frequency end of the spectrum without limiting the high-frequencies beyond the natural earth response (Q-factor). These 'unconventional' techniques focus on the receiver-side ghost, and commonly used are co-located velocity and pressure sensors and dual-depth hydrophone or variable depth hydrophones, which either capture phase or timing differences respectively of the receiver ghost. All these methods rely on processing to achieve the final receiver side de-ghosted data as the 'dumb sum' of the measurements will lead to poor results, or post-stack broadband data in the case of slant streamer. With sufficient signal-to-noise in the data it is possible to de-ghost the receivers towed at a moderate single depth by tuning the acquisition design, with consideration of the source emission response in combination with the streamer reception response. A test line was acquired that shows the equivalency of slant streamer and flat depth streamers in terms of post-stack amplitude spectra, showing that the acquisition design and pre-stack deghosting processing methodology is effective in providing broadband data.