塔里木盆地前陆冲断带含油气构造样式及成藏主控因素

Petroliferous Structural Styles and Oil-Accumulation Control Factors in Foreland Thrust Belt in Tarim Basin

塔里木盆地前陆冲断带具有丰富的油气资源,油气主要分布在前陆冲断带与逆冲断层相关的构造圈闭中。通过研究前陆冲断带构造特征,建立了横向叠瓦式、垂向叠瓦式、台阶状叠瓦式、单冲背斜式、双冲背斜式、对冲背斜式、背冲背斜式、同心背斜式和反冲断鼻式等9种含油气构造样式。构造区带和构造样式的多样性,以及与烃源层、储集层和盖层空间组合关系的多样性,形成了多种多样的油气成藏模式。无论哪种成藏模式,断层和盖层都是决定天然气成藏的关键要素。以断层发育为核心的断-源-储-盖的空间组合决定了圈闭的形成、油气的输导能力、圈闭的封闭性和充满度,从而最终决定了天然气的成藏。

The foreland thrust belt in Tarim basin is rich in natural gas resources, where the hydrocarbons are mainly found in structural traps related with the foreland thrust belt and the thrust faults. According to the structural characteristics of the foreland thrust belt, nine types of petroliferous structural styles are built up, namely, lateral imbricate, vertical imbricate, step-like imbricate, single thrust anticline, double thrust anticline, ramp anticline, back thrust anticline, concentric anticline and inverse thrust faulted nose types. The variety of struc- tural zones and styles and the diversity of spatial assemblages with source rock, reservoir rock and cap rock can form various oil-gas accu- mulation patterns, of which the fault and cap rocks are the decisive factors for natural gas accumulation in this area, because the spatial as- semblages of fault-source-reservoir-cap rocks dominated by fault development determine the trap shape, oil-gas deliverability, trap sealing and charging rate.