Upside down Rayleigh-Marchenko: a practical, yet exact redatuming scheme for seabed seismic acquisitions

Abstract: Ocean-bottom seismic plays a crucial role in resource exploration and monitoring. However, despite its undoubted potential, the use of coarse receiver geometries poses challenges to accurate wavefield redatuming. This in turn, affects the quality of subsequent imaging and reservoir charactherization products. We propose a reciprocal version of the Rayleigh-Marchenko method, called upside down Rayleigh-Marchenko, where all spatial integrals are performed over the (usually much better-sampled) source carpet; this results in a theoretically exact redatuming scheme, which can handle irregular and sparse receiver geometries. The proposed method requires availability of multi-component receivers and either dual-sensor sources or a pre-processing step of model-based source deghosting, and utilizes only the down-going component of the receiver-side wavefield; as such, it can be interpreted as a full-wavefield extension of the mirror imaging method commonly used in seabed settings. Two synthetic examples are used to showcase the effectiveness of the proposed method, starting from the ideal scenario of finely and regularly sampled sources and receivers, and later considering different levels of decimation for the receiver array. Migrated images as well as common-angle gathers reveal that our method can be used to produce structural and amplitude-friendly imaging outputs with minimal data pre-processing.