Broadband Imaing with Different Water Depth Seismic Data

In marine seismic exploration, the sea surface ghost reflections are recorded simultaneously with the effective wavefiled, because air guns and detectors are located at a few meters below the water. The ghost will modulate the notch frequencies and reduce their energy, especially the useful low frequency information, because the usable seismic bandwidth is normally between the first and second notch. The ghost removal (so-called deghosting) has been a long-standing problem, which is one of important steps for marine seismic data processing. Recently, many broadband seismic methods of deghosting have been improved from seismic acquisition to processing, and have opened a door to extract more geological information from seismic data.

In this paper, we show that the ghost is a 3D propagation operator with the propagation angles (or offsets) changing, and the notch frequency moves to high frequency with the angle increasing by comparing synthetic data sets and field data sets. The RTM deghosting is applied to shallow water streamer data, OBC data, and deep water streamer data, respectively. The results prove that the RTM deghosting can improve the imaging quality. The method could be a potential and practical technology for broadband seismic processing.