惠民凹陷临南斜坡带油气纵向运移及其控制因素

惠民凹陷临南斜坡带油气纵向分布特征为 :曲堤地垒发现 4套主要的含油层系 ,西南缓坡带只在沙四上亚段发现了含油气层位 ,白桥—仁风潜山带无油气显示 ,夏口断裂带下降盘油气主要集中分布在沙三段、沙二段。认为控制油气沿断层纵向运移的地质因素有 :发育馆三段和沙一段区域性盖层 ;全区大规模油气运移期所有断层的活动都较弱 ,限制了油气的纵向运移 ;断裂带具有走滑性质 ,限制了纵向运移 ;斜坡带远离油源 ,油源不充足 ,同时只在局部地区存在异常压力带 ,垂向运移能量不足。曲堤油田纵向含油层系长是油源充足、晚期断层活动强烈造成的 ,而西南缓坡带发生油气纵向运移的可能性小 ,勘探目标应集中在沙一段区域盖层之下的层位。图 1参 5(王孝陵摘 )

Hydrocarbon vertical migration and its controlling factors of Linnan slope belt in Huimin depression

The vertical distribution of oil and gas in the Linnan slope belt is characterized by (1)4 sets of major oil-bearing strata exist in Qudi horst, (2)oil-bearing horizon is only formed in the Upper S 4 of the southwestern gentle slope, (3)no oil/gas show occurs in Baiqiao-Renfeng burried-hill belt and (4)oil and gas are mainly concentrated in S 2 and S 3 of the down throw side of Xiakou faulted belt. Based on vertical hydrocarbon distribution properties, a systematic study of the geologic factors decided oil's migration along faults was studied. These factors are regional cap rock, the intensities of fault activity, strike-slip properties, the abundant degree of oil source and abnormal formation pressure. Qudi oil field's long vertical distribution properties is the reason for abundant oil source and intense fault activity. The possibility of hydrocarbon vertical migration is very little in slope belts, so the target of exploration should centers on below formations.