CGGVeritas will acquire two 2D seismic surveys offshore Gabon. These surveys will provide high-quality and targeted data to complement the 10th Gabonese License Round, recently announced as taking place between June and December 2010. The round will be Gabon's first since 1999 and will focus on the highly prospective deepwater pre-salt; a region analogous to that of the recent large deepwater discoveries offshore Brazil.

The two surveys will be located in the north and south of Gabon's underexplored deepwater blocks. In the north (Zone Nord) CGGVeritas will acquire a 2,200 km grid specifically designed to highlight Tertiary and Cretaceous plays. In the south (Zone Sud) a 7,400 km very long-offset survey will provide the best possible imaging beneath the Aptian salt to help identify potential traps.

The Zone Sud survey is part of a three-phase program designed by CGGVeritas to provide a full understanding of the region in a timely and cost-effective way. First, basin-wide depth modeling will be undertaken using existing data and a CGGVeritas test line. During the second phase a comprehensive gravity gradiometry survey will provide detail on the salt architecture. This information will be used to constrain PSDM models. The third phase is the acquisition of a targeted 2D grid. The potential for further acquisition, including 3D, will be assessed after completion of the three-phase program.

Chief Geologist CGGVeritas EAME region, Steve Toothill, believes, "The complexity of the salt bodies in the South Gabon Basin would warrant 3D seismic coverage. However, to shoot a 3D survey over the whole area of more than 50,000 sq km would take too long and be prohibitively expensive. A well planned 2D survey, specifically designed to target below the salt, will be sufficient to delineate structures. This will allow oil companies to evaluate the area, make their bids and then follow up with high-specification 3D surveys, such as wide-azimuth, to provide better illumination below the salt."

Earlier this year the Direction Generale des Hydrocarbures (DGH) selected CGGVeritas to assess the hydrocarbon opportunities in Gabon's deepwater, assist with the upcoming License Round and work programs, and conduct a targeted seismic program.

Jim Gulland, Business Development Manager, CGGVeritas EAME Data Library, believes "There is a lot of older seismic offshore Gabon, but it all targets the post-salt. Because of the complexity of imaging the sub-salt, new techniques, such as the approach we are offering, are needed to specifically identify and illuminate these plays."

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