Joint 3D deghosting of multiple vintages

While most marine baseline surveys do not use broadband techniques, increasingly more monitor surveys are being adapted to broadband techniques that often use different receiver-depth profiles (e.g., deeper or variable-depth). A regular matching filter that has been commonly used in 4D time-lapse processing may be insufficient to normalize the wavelet difference between baseline data and monitor data because of the large difference in receiver-depth profiles. Deghosting can effectively remove the wavelet difference among vintages caused by different receiver depths. However, deghosting different vintages separately may cause inconsistent deghosting of common events and thus create false 4D signals. We propose a joint inversion scheme that uses both the baseline and monitor data (or more vintages) that deghosts common events consistently while preserving the difference among vintages. Using synthetic and field data, we demonstrate that joint deghosting baseline and monitor data provides a more accurate ghost removal and a more reliable 4D difference over separate deghosting of both data.