巴西坎波斯盆地和桑托斯盆地油气分布差异及主控因素

摘要

巴西坎波斯盆地和桑托斯盆地均为典型的被动陆缘盆地。随着勘探程度的增加和近年来在桑托斯盆地深水区盐下油气的重大发现，坎波斯盆地和桑托斯盆地之间的构造沉积演化和油气地质特征的差异性越来越明显。通过对坎波斯盆地和桑托斯盆地区域地质特征和油气成藏条件差异性的比较，总结出两个盆地油气分布特征的截然不同。研究表明，盐窗比较发育的坎波斯盆地中已发现的油气主要富集于盐上浊积砂岩，而连续盐岩发育的桑托斯盆地已发现的油气则主要富集于盐下湖相碳酸盐岩。对于盐下层系，连续分布的盐岩和圣保罗高地的发育控制了盐下层系油气的分布；对于盐上层系，盐相关构造的发育则为油气垂向运移提供了有利通道，从而控制了盐上油气藏的形成与分布。%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.