A Novel 3-D De-multiple Workflow for Shallow Water Environments - a Case Study from the Brage field, North Sea

In shallow water environments, near surface reflectivity information is poorly recorded with 3-D towed streamer acquisition geometries. Therefore, the missing information must be reconstructed in the data prior to the de-multiple step. For this purpose, assumptions are typically made on shallow reflectivities and velocities. In the presented workflow, we use full waveform inversion and imaging with multiples, in order to extract the required information from the data acquired with dual-sensor towed streamer system. Then multiple models are generated by wavefield extrapolation. A comparison is shown on real data from North Sea, where the de-multiple processing is run once using a priori information on shallow multiple generators and then through the new workflow, which demonstrates that the extra information recovered has a significant impact on the effectiveness of the de-multiple process.