Impact of salt on hydrocarbon accumulation in South Atlantic passive margin basins

South Atlantic passive margin basins experienced a similar tectonic evolution and regionally distributed salt was deposited during the Aptian.Based on a comprehensive study of regional tectonics, depositional environment and hydrocarbon accumulation, integrated with the study of salt-related structural styles determined by analyzing regional seismic sections, three tectonic belts, which include extensional domain, transitional domain and compressional domain, were recognized in the 6 main salt basins.The pre-salt source rocks in the Brazil salt basins are still in the oil window.In West Africa, the post-salt source rocks experienced a higher maturation rate than the pre-salt source rocks.The salt has a relatively higher thermal conductivity and can restrain the hydrocarbon generation of the pre-salt source rocks but accelerate that of the post-salt source rocks.The salt flow resulted in several kinds of salt-related structural traps for hydrocarbon accumulation in the post-salt sequences.Reserves in the post-salt related structural traps account for 84.8% of the total post-salt reserves.The salt windows developed in the extensional domain served as hydrocarbon migration pathways and controlled hydrocarbon accumulations in the post-salt sequence.The thick salt provided a regional cap rock, which controlled the pre-salt hydrocarbon accumulations in the transitional-compressional domain.