反转构造特征及其在巴西桑托斯盆地油气勘探中的应用

Inversion structure and its application in petroleum exploration in Santos Basin,Brazil

为了揭示反转构造的成藏特征,系统总结了反转构造的类型特征、构造样式及形成机制,并对桑托斯盆地的勘探实例开展了分析。研究表明,正反转构造是一种重要的含油气圈闭,其发育演化与所受的挤压应力强度相关,在轻微、中等反转阶段,主要发育挠曲褶皱反转构造,在强烈和全部反转阶段,主要表现为断层强烈逆冲反转,发育断层相关型构造;反转构造是区域构造事件的响应,热体制变化和区域构造体制变化是2种主要的构造反转动力机制。正反转构造具有近源供烃,断裂-裂缝等运移通道发育以及圈闭可靠、规模大等特征,油气“生-汇-聚”时空匹配关系良好,是一种重要的油气藏类型。

To reveal the hydrocarbon accumulation characteristics of inversion structures,the types,styles,and formation mechanism of inversion structures are summarized,and exploration examples of the Santos Basin,Brazil,were analyzed.Results show that positive-inversion structures are important hydrocarbon-bearing traps.Their development and evolution are related to compressive stress intensity.In slight or intermediate inversion stage,they mainly develop flexural fold inversion structures.In strong or full inversion stages,they mainly show strong thrusting and develop fault-related inversion structures.Inversion structures are the response of regional tectonic events.Thermal regime change and regional tectonic regime change are two main tectonic counter-rotational force mechanisms.Positive inversion structures are characterized by near-source hydrocarbon supply,development of migration channels such as faults and fractures,and reliable and large-scale traps.In addition,positive inversion structures provide a good condition in which hydrocarbon generation,migration,and accumulation are well-matched in space and time,forming an important reservoir type.