Abstract:

Brazilian Campos and Santos basins are typical passive continental margin basins. Recently, with the increasing exploration and major oil and gas discoveries in the deep water pre-salt reservoirs in the Santos basin, the difference of tectono-sedimentary evolution and petroleum geology between these two basins becomes more obvious. The comparison of regional geological setting and hydrocarbon accumulation conditions reveals contrasting characteristics of hydrocarbon distribution in these two basins. In the Campos basin where salt windows are more common, oil and gas are mainly enriched in the supra-salt turbidite sanstones; while in the Santos basin where salt is continuous, oil and gas are mainly enriched in pre-salt lacustrine carbonates. Continuous salt and paleo-high structures such as Sao Paulo plateau, are the main controls on the habitat of oil and gas in the pre-salt sequences. Salt-related structures and deep faults, which act as the vertical migration pathways, control the formation and occurrence of oil and gas accumulations in the suprasalt sequences.

Key words: Campos basin, Santos basin, salt, petroleum gas, passive margin basin