Pore Pressure at the Post-Salt Albian Carbonates in Santos and Campos Basins

Summary This work analyzes the pore pressure regimes in the Albian carbonates deposited above the salt layer at the Southeast Atlantic margin in Brazil. The study area consists in Santos Basin shallow waters and in Campos Basin deep waters. The settings are carbonate layers folded over anticlinal salt dome structures. An effort has been done to associate the wells pore pressure data with the carbonate layers structures interpreted from seismic sections. At each dome the Albian carbonate reservoirs are found at a local pore pressure regime either at normal or slight overpressure or at high overpressure. One possible way for a high pore pressure increase is lateral and vertical pore pressure transfer from a deeper interval down the flanks of the anticlinal dome structures. The pressure connection may be restricted just to the Albian or it may involve the pre-salt Aptian interval through salt windows around the domes. Another possible scenario for overpressure mechanism consists on oil or gas generation in the Albian. The prediction of the Albian carbonates pore pressure is necessary for well drilling design to both exploratory targets the post-salt and the pre-salt.