Improved Deep Target Reservoir Imaging with Broadband WATS Data in the East China Sea

Summary A broadband Wide-Azimuth Towed-Streamer (WATS) survey was acquired in a shallow water region of offshore China for resolving strike direction narrow-azimuth acquisition shortcomings. This WATS acquisition is much sparser than WATS surveys in deep water environments due to the one-side WATS configuration. The combination of sparse acquisition, shallow water, and deep targets, require optimal utilization of the side-gun data as the key to final imaging improvements. A comprehensive flow for resolving the challenges of de-ghosting and de-multiple for sparse and shallow wide-azimuth data is presented in the paper. Side gun data clearly enhances the final target reservoir imaging and better ties the well by including dip direction information. Contribution analysis of side guns in this survey shows that better azimuth distribution shall play a more significant role than far offsets in the final imaging, which provides valuable guidance for future acquisition designs in similar geographical and geological conditions.