惠民凹陷西南缓坡带断层的封闭性

Fault sealing of south-west gentle slope belt in Huimin depression

为了解断层对惠民凹陷西南缓坡带油气成藏的作用,在分析缓坡带断层发育特征的基础上,采用泥岩涂抹系数法和断面压力与砂泥比结合法对研究区内主要控油断层的封闭性进行研究。研究结果表明:该区断层的封闭性在时空上存在着较大的差异,并在油气运、聚过程中起着不同的作用;夏口断层控制着运移至缓坡带的油气量,其东段侧向封闭差,可以连接源岩和圈闭形成油气运移的通道,西段侧向封闭好,阻止油气运移形成油气藏;缓坡带内三、四级断层控制着油气运、聚的层位;研究区北部沙四段(Es4)地层中的断块圈闭应为下一步重要的勘探目标。

In order to study the role of fault on hydrocarbon accumulation of south-west gentle slope in Huimin depression, the fault sealing was researched through clay smearing factor and fault plane pressure combined with sand-clay ratio method based on the analysis of development characteristics of oil-controlled fault in gentle slope. The results show that the fault sealing in this area shows a great difference in time and space, and plays different roles in hydrocarbon migration and accumulation. Xiakou fault controls oil migrating to the gentle slope. The poor fault sealing of east section can form hydrocarbon migration channel through connecting source rock and trap, while the fault sealing of west section is good, which can form reservoirs by preventing hydrocarbon from migrating. The third or fourth grade faults within gentle slope control hydrocarbon migration and accumulation layer. Further exploration targets should be focused on the fault-block traps in the Es4 formation in the northern of the study area.