滑脱构造与油气成藏的关系

The relationship between detachment structure and hydrocarbon accumulation

滑脱构造对盆地的形成演化和油气成藏有着重要的作用。从几何学和动力学等方面,分析了滑脱构造的形成机制、变形特征、构造岩特征及其与油气成藏的关系。研究表明:滑脱构造的形成除了受外在动力机制控制,还与地层属性如不整合面、地层岩性及物性特征有关。其变形特征主要受控于滑脱层的深浅,地层的温压及所受应力大小,常伴生有三角带、叠瓦状构造和双重构造等。碎裂岩作为滑脱构造中典型岩石类型受到动力变质作用,发育大量裂缝和溶洞。滑脱构造形成的高温场、构造圈闭和岩性圈闭、滑脱断裂带、碎裂岩裂缝,为油气的生成、运移和成藏创造了很好的条件。

Detachment structure plays an important role in basin evolution and hydrocarbon accumulation.The formation mechanism of detachment structure,deformation feature,tectonite feature and their relationship with hydrocarbon accumulation are analyzed in respects of geometry and dynamics,etc.The study indicates that the formation of detachment structure is not only controlled by external dynamic mechanism,but related to stratigraphic attributes such as unconformity surface,lithology and physical properties as well.The deformation feature is mainly controlled by the depth of detached layer,formation pressure,temperature and stress,often associated with triangular belt,imbricate and duplex structures.Cataclasite as a typical rock type in detachment structure had developed numerous fractures and caves under dynamic metamorphism action.The high-temperature field,structural and lithologic traps,detachment fault zone and cataclasite fractures of detachment structure are favorable conditions for hydrocarbon generation,migration and accumulation.