Page 30: of Marine Technology Magazine (October 2014)

Along the last decade major improve- ments in the quality of subsurface mapping of geological formations containing complex salt bodies have taken place with the introduction of broadband seismic survey technology. Since the dis- covery of the Lula oil Þ eld in 2006, CGGÕs BroadSeis has been involved in the most important pre-salt discoveries. Marine Tech- nology ReporterÕs Correspondent in Brazil, Claudio Paschoa gives us some insight on CGGÕs experience in shooting seismic of large areas along the pre-salt rich Santos Basin, with its trademark BroadSeis, 3D broadband seismic data acquisition system. New PSDM 3D seismic reß ection data acquired from the highly proliÞ c Santos Basin provides comprehensive insight into, the evaporite architecture and potential pre-salt hydro- carbon reservoirs, allowing geologists to have a better un- derstanding of these deepwater geological formations. ÒThe pre-salt region runs from the south of the state of Bahia, to the north of the state of Santa Catarina, yet some remnants of the salt layer can be found further north, such as along the Sergipe/Alagoas Basin,Ó said Luiz Braga Ph.D, VP Ð Director of Geomarket Latin America for CGG. Pre-salt reservoirs are always found in carbonate rock formations beneath salt layers and salt domes that can be up to 2,000 meters thick, which act as seals, above the salt lay complex and heterogeneous rock formations that can be as thick as the salt layer and all this under 2,000 meters of water or more. Acquiring seismic data that clearly shows the boundaries and composition of different layers during visualization is a daunting task for geophysicists and engineers alike. Pre-salt Seismic Exploration It is widely known be that early Petrobras seismic surveys in image courtesy of CGG Broadband Seismic for Enhanced Pre-salt Imaging By Claudio Pascoa Above: The Geo Coral, C-class vessel towing streamers. 30 MTROctober 2014MTR #8 (18-33).indd 30MTR #8 (18-33).indd 3010/10/2014 2:33:11 PM10/10/2014 2:33:11 PM