Following Gabonese 11th deepwater licensing round, CGG has worked with the Direction Generale des Hydrocarbures of Gabon (DGH) to acquire and process over 25,000 km2 of new 3D BroadSeis multi-client seismic data over blocks in the South Basin.

The company informed that the fast-track pre-stack time-migrated dataset for the survey is available now, along with sample pre-stack depth reverse time-migrated (RTM) data in one area.

The final RTM for the whole of the survey area should be available this summer.

Early seismic imaging results indicate the presence of thick syn-rift and sag sequences below the salt, which are the key intervals of a pre-salt petroleum system and indicate many exciting prospects, some of which continue beyond the borders of the survey so that their full extent cannot be gauged, CGG explained.

Although the dataset delivers images of the subsurface in this area, additional data are being acquired to improve the imaging.

Tailored multi-vessel survey design is enabling longer offsets, up to 14 km in the same orientation as the original data, to be acquired over block F14. In block F15, adjacent to the Congo border, a second orthogonal azimuth of the full range of offsets, including those up to 14 km, is being acquired.

Longer offsets and dual azimuths are expected to improve the sub-salt illumination and provide even greater clarity of the most challenging structures.

In order to acquire these long offsets an additional source vessel is being deployed, the company added.