塔里木多旋回盆地复合构造样式初步分析

塔里木盆地多旋回的演化历史导致了多期次的复合构造变形作用。不同方式的构造运动导致了不同方式的复合,不同等级和不同规模的变形叠加导致了不同级次的复合构造。根据造成复合构造的应力场变化的特征,结合具体实例将塔里木盆地复合构造划分为8种主要类型:继承性挤压、继承性走滑、挤压——走滑、走滑——挤压、拉张——挤压、挤压——拉张、挤压——重力和重力——挤压复合构造。复合构造为油气运移提供了新的运移动力场及高效输导体系。构造复合一方面可能会加大早期构造的幅度并使其更为复杂,另一方面会导致各种圈闭更为复杂的平面组合与纵向叠置方式。构造复合对早期已聚集的油气存在一定的破坏作用,同时,由多油源、多期生烃、多通道、多圈闭类型和多成藏期组成的成藏条件也在复合构造中形成了以塔河——轮南特大型油气田为代表的复式油气聚集带。

A PRELIMINARY ANALYSIS ON COMPOUND STRUCTURAL STYLES IN THE TARIM POLYCYCLIC BASIN

The polycyclic evolution history of the Tarim Basin resulted in the multi-stage compound structural deformation, and varied compound modes occurred in each tectonic event, during that time the deformation with superposition of various orders and scales resulted from the various stage of compound structures. Based on the re-constructions of the variation of the strain field during which the compound structures created, combined with the practical deformation modes, eight main types of the compound structures could be distinguished in the Tarim Basin, namely, inherited compressive compound structure, inherited strike-slipping one, compression——strike-slipping one, strike-slipping——compressional one, extension——compressional one, compression——extensional one, compression——gravity one and gravity——compressional one. The superposition of varied deformation could act as a new driving force for the migration of oil and gas, and afford high efficient migration route. The structural compound might enhance the amplitude of the early structures, create more complicated structures, and simultaneously result in the more complex planar combination and vertical overlapped modes of the different traps. The structure composition had a certain harmful effect on previous reservoir. And meanwhile, the petroleum accumulation conditions with the characteristics of multiple source rocks, multi-stage hydrocarbon generation, multiple migration routes, multiple types of traps and multi-stage petroleum accumulation might result in composite oil and gas accumulational belts, for example, the Tahe——Lunnan super-large oil-gas field.