Seismic migration of water-bottom-related multiples accelerated by random phase-encoding strategy

Marine seismic multiples contain more structure information than primaries and should be considered in migrations. However, multiple migrations suffer from severe crosstalks generated by interferences among undesirable multiples. It has been proven that the water-bottom-related multiple migration can suppress crosstalks greatly. However, if all associated consecutive-order multiples are considered, the computation cost is extremely high. To settle this issue, a phase-encoding-based multiple migration is proposed. Supergathers are first created by randomly phase-encoding consecutive-order multiples and stacking-encoded multiples. By migrating supergathers, the proposed method can fulfil migrations of all order multiples simultaneously, thereby reducing the computation cost significantly. We use a three-layer model and the Pluto 1.5 model for numerical comparisons. The results reveal that the method can retrieve high-quality images and increase computation efficiency considerably.