惠民凹陷中央隆起带油气事件成藏规律

Rules of Event Accumulation of Hydrocarbon in Central Uplift Belt in Huimin Depression

惠民凹陷中央隆起带断裂、火山和地震活动等事件性地质作用影响了该区油气的生成、运移和聚集。油气事件成藏模式流体运移以突发性涌流方式为主。孔隙流体压力有利于岩石产生破裂,但是中央隆起带的构造活动是造成岩石破裂、流体瞬态运移的主控因素。事件成藏过程可以发生在油气发生连续运移之前和之后,主要受构造活动发生期的控制;油气事件成藏过程可以分为突发事件前稳定期、突发事件非稳定期和突发事件后稳定期3个阶段,其中突发事件非稳定期是油气发生事件成藏的主要时期。惠民凹陷中央隆起带的油气垂向上异层同源的分布特征是油气事件成藏的结果。

Event geologic functions,such as fault,volcano and earthquake,play a great role in oil and gas formation,migration and accumulation in central uplift belt,Huimin depression.In event accumulation of hydrocarbon progress,fluid rush out of the source rock and flow rapidly in its pathway.Pore fluid pressure can do favor to rock's rupture,while tectonic movement is the main factor that induces the rupture of source rock and the episodic fluid migration.Event accumulation of hydrocarbon can occur before or after the continuous oil and gas migration,it depends on the active period of the tectonic movement.The progress of oil and gas pool-forming can be divided to three parts:static period before the gusty event,unstable period during the gusty event,static period after the gusty event,among which,the second is the main period of the event accumulation of hydrocarbon.The features of vertical oil and gas distribution are the results of event accumulation of hydrocarbon.