高邮凹陷环深凹带戴南组变换带特征及其成藏意义

Characteristics of Transfer Zones and Significance for Accumulation of Dainan Formation in Area Around Deep Sag Belt of Gaoyou Sag

在地震解释及地质研究分析的基础上,结合前人对变换带的研究,讨论了高邮凹陷环深凹带戴南组变换带类型、特征,并总结其在沉积体系及油气成藏中的控制作用.研究表明,研究区变换构造主要形成在侧列伸展断层叠覆、分段连接部位或次级凹陷之间,主要发育同向接力式和横向消减式构造变换带,变换构造包括走向斜坡、横向断鼻凸起和调节断层.构造变换带控制着富烃洼陷的形成,并引导古水系流入湖盆,在对应的断层下降盘形成三角洲前缘、扇三角洲前缘及浊积扇砂体,有利于发育富砂储集层;研究区变换带发育复杂的调节断层和多种样式的圈闭,有利于油气的运移与成藏,并对变换带控制的隐蔽油气藏进行预测.

Based on the seismic interpretation, geology analysis and the previous classification research, we discuss the types and features of structural transfer zones of dainan formation in the area around deep sag belt of Gaoyou sag, and summarize the controlling effect on the depositional system and hydrocarbon accumulation. The study shows that the transfer structure develops in the locations where lateral extensional faults overlapping, segment connection or the between of sub-sags. The transfer zones include synthetic relaying and transverse declining. The types of transfer structures are strike slope, lateral nasal uplift and transfer fault. The structural transfer zones control the development of prolific hydrocarbon secondary-sag and guide the palaeo drainage pattern flowing into lake- basin. The sandbodies of delta front, fan-delta front and turbidite fan developed in the corresponding downthrow of fault are favorable to the formation of sandstone reservoirs. The complicated transfer fault and various tectonic styles of trap are favorable to the hydrocarbon migration and accumulation, and to predicte the subtle reservoirs which controlled by the transfer zones.