复合反“Y”字型构造中油气二次运移与聚集过程物理模拟研究——以黄骅坳陷港东构造带为例

Physical Simulation of Secondary Petroleum Migration and Accumulation Process in Complicated Reserve Y-type Structures——By Taking Gangdong Tectonic Belt in Huanghua Depression for Example

石油的二次运移是个非常复杂的过程。利用物理模拟试验,对港东构造带复合反"Y"字型构造带油气运移与聚集过程进行研究,得出以下结论:①在复合反"Y"字型构造中,当油气运移的主要动力为异常压力时,不同的压力条件导致不同的油气运移与聚集;当压力较小时,油气首先沿断层向上运移然后在上部地层聚集,然后聚集到下部地层即油气"从上向下"聚集;当压力较大时,油气不但沿断层向上运移而且在断层两旁的地层中聚集,油气是从下部地层开始聚集,然后聚集到上部地层即油气"从下向上"聚集。②与油源断层伴生的分支断层对石油的运移和聚集有重要的影响。受到这些分支断层的影响,石油能够更加容易地运移到较远的地层中,而且能够在离油源断层较远的圈闭中形成油气藏。

Through physical simulation of secondary oil migration and accumulation process in Y-type structures of complicated reserves,it is concluded that ①when the main driving forces are abnormal pressure,different secondary oil migrations and accumulation processes are induced from different abnormal pressures.When the abnormal pressure is smaller,petroleum migrates along the faults and accumulates upward first,then downward;that's to say,oil accumulates from the top to bottom;when the abnormal pressure is larger,oil migrates along the faults and accumulates downward first,then upward;that's to say,oil accumulates from the bottom to top;②branching faults associated with oil-resource faults have an important effect on the oil migration and accumulation;oil can migrate to farside areas and accumulate in farside traps through the branching faults.