夏口断层对惠民南部地区油气成藏的控制作用

CONTROLLING OF XIAKOU FAULT ON HYDROCARBON ACCUMULATION IN THE SOUTHERN PART OF HUIMIN DEPRESSION

夏口断层对惠民南部地区的油气成藏起着重要的控制作用。通过岩性对置、泥岩涂抹(RSG)、紧闭指数等参数对夏口断层封闭性进行定量评价表明,夏口断层不同位置封闭性差异明显。在对夏口断层断面形态分析基础上,结合物理实验模拟,确定夏口断层作为惠民南部地区的运移通道,主要存在东西两个优势方向,目前发现的油气主要集中在这两个方向上。通过分析夏口断层的活动期与油气运移期的配置关系,得出明化镇期伴随主力烃源岩大量排烃,夏口断层成为惠民南部地区主要的油气运移通道。夏口断层东西两端复杂的封闭与开启状态,决定了惠民南部地区油气分布的复杂性。

Xiakou fault plays an important role in controlling oil-gas accumulation in Huimin depression.By analyzing the lithologic association on two sides of fault,the mudstone-smearing and fault tightness index,Xiakou fault-sealing is studied quantitatively.The result shows that Xiakou fault sealing varies significantly in different locations.Based on the analysis of the fractured surface form of Xiakou fault,combined with the oil-gas migration simulation experiment,Xiakou fault is determined as the migration path in the south Huimin depression.It is found that Xiakou fault has two dominant migration channels,which contain most of the oil and gas.According to the relationship between faulting stage and hydrocarbon migration period of Xiakou fault,Xiakou fault accounts for the major oil and gas migration pathways in the south of Huimin depression,with the main hydrocarbon source rocks rowing in bulk.The complex closure property of Xiakou fault leads to the uneven oil-gas distribution in the south of Huimin depression.