【摘要】 鄂尔多斯盆地延长组长2油藏是盆地中生界的一套主力含油层,前人学者对长2油藏的成藏主控因素进行了多方面的研究,但其研究存在两点不足之处:一是未结合上下层系综合研究长2油藏成藏控制因素;二是对于经历了长距离侧向运移的长2油藏成藏原因研究不清楚,缺乏对断层的研究。综合前人研究认为,盖层及遮挡条件是油气成藏的一个主控因素,但是很难去定义某个地层是否为有效的盖层或遮挡条件;应考虑延长组内部可能发育小的断层,而不是许多学者所说的盆地内部断层不发育。更多还原

【Abstract】 Chang 2 reservoir of Yanchang formation is a main reservoir in Mesozoic of Ordos Basin. Previous scholars have studied the main controlling factors of Chang 2 reservoir in many aspects, while there exist two shortcomings in their studies. On one hand, their studies on the controlling factors were not combined with the upper and lower strata.On the other hand, the reasons for Chang 2 reservoir accumulation were not clear, which experienced long distance lateral migration and there is lacking of fault studies. Based on the previous studies, it is considered that the caprock or a sheltering condition is one of the main controlling factors for hydrocarbon accumulation, but it is difficult to define whether a certain formation is an effective caprock or a sheltering condition. It should be considered that there may be small faults in Yanchang formation, rather than that the faults in the basin are not developed, just as many scholars once said.更多还原