长垣主断层(长垣断层)是东濮凹陷西部斜坡带的二级同沉积断层,断层封闭性对油气运聚具有重要作用.利用断层生长指数、断面正压力、断层泥比率和断层两侧岩性对置关系分析了长垣断层的封闭性,结果表明:长垣断层由南向北活动时期逐渐变晚,活动强度南强北弱,断层的断距和垂向封闭性差异是油气差异性富集的主控因素；沙二段上亚段厚层泥岩的涂抹作用使长垣断层侧向封闭性增强；长垣断层下降盘沙二段上亚段与上升盘对置地层的南北向差异导致上升盘油气富集层位的差异;长垣断层上升盘的伴生断层为构造断层,活动时期较早,垂向封闭性强,油气侧向运移至长垣断层后,其聚集受断层两侧岩性对置关系控制.%Changyuan fault is a secondary contemporaneous fault, and its sealing factors play a significant role in hydrocarbon migration and accumulation on western slop in the Dongpu depression. Analyzing on fault sealing characteristics, including oil and gas transportation based on fault growth index, normal pressure on fault plane, shale gouge ratio(SGR), and lithology contraposition relationship of the fault, shows that,①Changyuan fault activated earlier and stronger in the south, and it became later and weaker in the north. These variety resulted sealing difference between the north and the south of Changyuan fault,②variety of the fault factors resulted the difference of normal pressure on fault plane along the fault strike, as well as the difference of sealing characteristics. Abrasion smear of upper Es2 formation strengthened the lateral sealing, the role of normal pressure on fault plane clay fillings increased the vertical sealing of Changyuan fault. Difference of lithology contraposition relationship between the north and the south of Changyuan fault resulted the difference of oil and gas accumulation in its footwall. Associating fault on footwall of Changyuan fault is a structural fault which activated earlier and is of vertical sealing, oil and gas migrated vertically along Changyuan main fault to Changyuan fractural zone and then migrated laterally. Hydrocarbon accumulation is dominated by lithology contraposition relationship of the fault.
展开▼
