Near Surface Gas and Fluid Escape Features – Hydrocarbon and Hazard Potential, Offshore Gabon

This paper outlines examples of near surface fluid and gas flow features observed in the seismic interpretation of the Gabon MegaSurvey. Features range from lone craters on the seabed to clusters of pockmarks that appear to have random distribution patterns and other clusters that have a clearly defined linear or channel-like trend. A description of the various pockmark features are given with possible explanations of their formation. The significance of pockmarks is described in the potential for hydrocarbon reserves and the importance of mapping them for sea floor hazards. Numerous amplitude anomalies are associated with these pockmarks as observed in the seismic data. These amplitude anomalies are potential hydrocarbon indicators which afford shallow drilling opportunities and reserves. Pockmarks also help to identify areas of seabed hazards for oil field operations. There is significant value in these pockmarks both in hydrocarbon reserves and oil field safety.