A Ghost Prediction Based OBC PZ Summation Method for Comolex Seabed
F. Sun, K. Yang and B. Hung
Event name: 77th EAGE Conference and Exhibition 2015
Session: Multi-component - P and S Wave Field Acquisition and Processing
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 3.71Mb )
Price: € 20
In ocean bottom acquisition, receiver side deghosting is normally done by summing together the hydrophone P and geophone Z data. A prerequisite for this method to work effectively is the precise calibration of geophones to hydrophones, so as to compensate for the differences in sensitivity and coupling. A “cross-ghosting” approach has been proposed to extrapolate geophone and hydrophone data to have the same manner for matching. However, as far as we know, existing cross-ghosting methods are based on a 1D geology assumption. In this paper, we describe a cross-ghosting method using 2D wave-equation extrapolation, which accurately predicts the ghost according to the structure of the sea-floor. By honoring the geology and angle dependency of ghosts, more data can be included for calibration, providing a more accurate geophone calibration filter with which to separate up-going and down-going wavefields. The method only needs the water depth information and water velocity, and has no limitation on subsurface geology or structure. We compared this algorithm to the conventional 1D method and results show the superiority of our approach.