Improved Interpretability via Dual-sensor Towed Streamer 3D Seismic - A Case Study from East China Sea

The geophysical objectives in the exploration for hydrocarbons in the East China Sea require 3D seismic data of sufficiently high quality to facilitate accurate structural and lithological interpretation of the deep reservoir plays (typically at a depth of 2.5 - 5.5 km). Conventional narrow bandwidth 3D seismic which contains the sea surface ghost lacks the required resolution of seismic structure and penetration of signal in the deep section which is characteristic of broadband seismic obtained via an acquisition de-ghosting solution. A 3D broadband seismic survey was commissioned in 2012 by the operator CNOOC using dual-sensor towed streamer acquisition system specifically designed to eliminate the sea surface receiver ghost. Comparison of data quality with an adjoining 3D conventional survey acquired in 2011 shows improved imaging of the highly developed fault systems, the associated deep reservoir plays, and basement. In particular, the more prominent amplitude response, and the better delineation of the different facies character, facilitates more accurate interpretation of the seismic data.