【摘要】 为了确定断层对鄂尔多斯盆地塔巴庙地区上古生界天然气富集成藏的控制作用,利用2 000km2高精度三维地震资料,进行断层的精细解释及山西组、太原组煤系地层均方根振幅地震属性的提取,分析断层的分布、成因及形成期,研究断层与天然气高产层段和富集区的关系,建立塔巴庙气田天然气成藏模式。结果表明:上古生界存在北东向断裂系统,断层多为高角度的小断距断层,断距20～60m;这些断层主要是基底断裂在燕山运动中、晚期重新活动造成上覆沉积盖层撕裂形成的;断层形成期与烃源岩生排烃期良好匹配,断层沟通了石炭系太原组、二叠系山西组煤系烃源岩和二叠系下石盒子组盒2段、盒3段岩性圈闭,既促使下伏天然气向盒2段、盒3段垂向汇流运移,同时又为有机酸的运移溶蚀提供通道,有效改善了邻近低渗砂体储层的孔渗性能,从而控制了塔巴庙地区主力目的层盒2段、盒3段天然气运聚成藏及高产富集区带的分布;断裂和大面积相对高孔渗砂体的叠合区域是天然气的有利富集区。更多还原

【Abstract】 In order to understand the control of fault on gas accumulation of Upper Paleozoic in Tabamiao Area of Ordos Basin,according to 2 000 km2 three-dimensional seismic profile with high accuracy,fault was fine interpreted,and root mean square amplitude seismic attributes of coal-bearing strata in Shanxi Formation and Taiyuan Formation were extracted;distribution,genesis and formation stage of fault were analyzed;the relationship of gas layer section with high yield and enrichment area to fault was discussed,and gas accumulation model in Tabamiao Area was built.The results showed that there was a NE fault system in Upper Paleozoic,the angles of faults were mostly high with minor slip,and the fault throw was 20-60 m;these faults were mainly formed by the tearing of overlying sedimentary covers,which were caused by the re-movement of basement faults during the middle and late of Yanshan Movement;formation stage of fault matched well with hydrocarbon generation and expulsion stages of hydrocarbon source rock,and fault connected the coal-bearing hydrocarbon source rock in Carboniferous Taiyuan Formation and Permian Shanxi Formation and the lithologic trap in He2 Member and He3 Member of Lower Shihezi Formation of Permian;the fault promoted the vertical conflux migration of gas to He2 Member and He3 Member,and provided a passage for the migration and dissolution of organic acid,so that porosity-permeability property of low-permeability sandstones nearby was improved,and the gas migration and accumulation in the main reservoir of He2 Member and He3 Member and the distribution of layer section with high yield and enrichment area were controlled;the overlapping areas of faults and large sandbodies with relatively high porosity and permeability were favorable for gas.更多还原