A Marine Broadband Case Study Offshore China

Abstract

The effect of the sea surface ghost on marine seismic acquisition is well understood. Shallow tow geometries recover high frequencies at the expense of attenuating low frequencies and deep tow geometries recover low frequencies at the expense of attenuating high frequencies. In recent years two dual streamer tow depth solutions (Over-Under and Sparse-Under) have been deployed, both of which use two streamers which are towed at two different depths. A 2D survey was acquired offshore China, in August 2009, utilizing three separate streamer depths (5, 17 and 23 m). This three streamer depth configuration allows for the benefits of the two broadband solutions to be evaluated against each other and against a shallow streamer single depth seismic measurement. This paper will review the theory behind the two combination techniques, compare the seismic datasets, and finalize with some conclusions on the relative benefits both in terms of seismic imaging and acquisition efficiency.