辽河坳陷大民屯凹陷古近系盖层特征及对油气系统的影响

辽河坳陷大民屯凹陷是著名的高凝油生产基地。本文从盖层分布特征、封盖性能等方面探讨两套区域盖层对油气富集的重要作用。通过流体超压研究，发现大民屯凹陷存在与两套区域盖层相对应的流体超压封盖系统。超压封盖对油气运聚有着重要作用。大民屯凹陷中可以划分为高蜡油油气系统和正常油气系统两个含油系统。两套区域封盖体系分别对高蜡油系统和正常油气系统起到非常重要的封盖作用。正是由于大民屯凹陷有严密的封盖体系，保证了其油气的高效聚集。

Characteristics of the Paleogene caprock and influence on petroleum systems in Damintun Sag of Liaohe Depression

The Damintun Sag in Liaohe Depression is a famous high pour-point oil production base.This paper discusses the importance of the two sets of regional mudstone caprocks to the oil and gas accumulation by analyzing the distribution features and sealing property of caprock.The study on the fluid overpressure shows that there are two fluid overpressure sealing systems which correspond to the two sets of caprocks.The overpressure sealing system plays an important role in oil and gas migration and accumulation.This sag can be divided into two petroliferous systems,the high wax petroleum system and the normal one.These two regional systems seal the high wax petroleum system and the normal system respectively.It is just the sealing systems which ensure the abundant oil and gas accumulation in Damintun Sag.