The Separation of Multipath Angle Domain Common Image Gathers for Complex Structures

Imaging complex subsuface targets, for example subalt sediments and salt flanks becomes more and more challenging in seismic exploration. When the cross-correlation image condition is used in reverse time migration for each source, the contributions are summed across all the time steps to give one migrated image. The stacked image includes contributions from all primary and prismatic waves, or even artifacts. Thus the final image summation contains a variety of wavefield distortions. Nevertheless, if the image time for each multipath arrival is saved during wavefield extrapolation, and apply image condition at their image times for multipath contributions, we can obtain the multipath partial images. The separate partial images can by displayed for the primary contributions, or any combination of different types of waves (with or without artifacts). The synthetic data from the Sigsbee2 model shows that the relative contributions of multipath arrivals to subsalt images are different.