贝尔凹陷构造演化及其对沉积和油气的控制作用

贝尔凹陷是海拉尔盆地南部的一个次级凹陷,凹陷内蕴藏着丰富的油气资源,是海拉尔盆地重要的油气探区之一。贝尔凹陷经历了三期构造演化,形成了三期不同类型的原型盆地,自下而上分别为下部伸展断陷盆地、中部裂后热沉降盆地和上部构造反转盆地。复杂的构造演化形成了复杂的断裂系统,贝尔凹陷纵向上主要发育了两套断裂系统,分别是发育于下部断陷盆地的下部断裂系统和发育于中部热沉降盆地的上部走滑断裂系统,上部构造反转盆地内断裂不发育。复杂的构造样式对凹陷内沉积体系的配置也起着很重要的控制作用。本文从贝尔凹陷构造演化和构造特征研究出发,分析了沉积作用对构造活动的响应,初步探讨了贝尔凹陷构造对油气藏形成的控制作用。

TECTONIC EVOLUTION AND ITS CONTROLLING ON SEDIMENTATION AND HYDROCARBON ACCUMULATION IN BEIR DEPRESSION

The Beir depression is a secondary depression of the Hailar basin which is abundant in oil and gas resources, and is one of the important hydrocarbon accumulation zones of the Hailar basin. The Beir depression underwent three episodes of tectonic evolution, accompanied by complicated structural patterns, forming three types of prototype basins: extensional fault basin in the lower, post-rifting thermal subsidence basin in the middle and inversion basin in the upper,respectively. There have been two faulted systems which were developed in the lower and middle prototype basins, respectively. From the basin tectonic evolutional process, depositional responses to the basin tectonic activities and tectonic controlling of the hydrocarbon migration and accumulation of the Beir depression have been analyzed and discussed in this paper.