徐家围子断陷深层构造演化与天然气聚集

通过4条地震剖面的构造解释和构造发育史研究。探讨了徐家围子地区深层的构造演化。认为徐家围子断陷深层构造格局的形成是在区域近南北向压扭应力作用下，地幔物质上涌诱导的低角度边界正断层倾滑作用的结果，经历了一个完整的伸展断陷盆地演化序列。火石岭期初始张裂，沙河子期强烈扩张，营城期断陷向坳陷转化．登娄库-泉头期断陷期后热冷却沉降期。徐西断裂和宋西断裂为两条主要控陷低角度正断层，徐西断裂活动期为火石岭-沙河子期。宋西断裂活动期为沙河子-营城期。从构造演化与深层天然气成藏的关系分析．深层构造作用是深层天然气成藏的主控因素之一。

Deep-stratum Structural Evolution and Natural Gas Accumulation in Xujiaweizi Fault Depression

Based on the structural interpretation and its growing history of 4 seismic profiles, a deep-stratum structural evolution is studied in Xujiaweizi area. It is thought that the formation of deep-stratum structural pattern in Xujiaweizi fault depression can be attributed to dip-slipping of low angle dominant boundary normal fault induced by streaming up of mantle in settings of transpression stress field with near N-S orientation, of which an integral elongational fault basin evolutional process is experienced. Initial opening Huoshiling period is intensively expanded in Shahezi period, transformed from faulted depression to sag in Yingcheng period, with heat-cooling subsidence in Denglouku-Quantou period. Xuzi and Songxi faults are 2 low angle dominant boundary normal faults, of which Xuxi fault activity is Huoshiling -Shahezi period, Songzi fault activity is Shahezi-Yingcheng period. From the aspects of the relationships between structural evolution and natural gas reservoir forming, it is revealed that the deep-stratum structure is one of the dominant factors controlling natural gas reservoir formation.