地层顶面形态对油气分布控制作用——以焉耆盆地为例

通过对焉耆盆地地层顶面构造及顶面形态分布特征的研究分析,将其分为斜坡区、平台区和鼻状区3种基本类型.盆地实际的构造顶面特征则由这3种基本类型复合而成.3种类型对盆地油气成藏有各自不同的作用.其中平台区和鼻状区对油气成藏有积极作用,而斜坡区则不利于油气的成藏.具体到某个盆地它们对油气成藏的作用要结合其他因素来决定,如盆地油源的充足程度就是个十分关键的因素.焉耆盆地现今油气分布受其二级构造带限制,几个重要的油气区都位于与生油洼陷毗邻的构造带上.对地层顶面构造形态与主要油气分布关系的研究认为,焉耆盆地油气分布与地层顶面构造特征有一定的相关性,盆地中从二级构造带伸向凹陷中的鼻状构造对于油气从源区到圈闭的聚集成藏有重要作用. 

CONTROL OF STRATA SUPERFACE FORMS TO HYDROCARBON DISTRIBUTION-A CASE STUDY OF THE YANQI BASIN

Based on the study of the distribution characteristics of strata superface structures and forms, the Yanqi Basin was divided into slope areas, platform areas and nose areas three basic types. The factual structural superface characteristics of the basin were composed of the three types. Each type played a different part in the hydrocarbon pool-formation of the basin. The platform and nose areas were positive to hydrocarbon pool-formation, and the slope areas were unfavorable. Other factors such as the sufficient degree of oil sources should also be considered. The present hydrocarbon distribution of the Yanqi Basin was limited by its secondary structural belts, and several important hydrocarbon-bearing areas were all located in the structural belts adjacent to oil-generating sags. By study on the relationship between strata superface structural forms and main hydrocarbon distribution, it was considered that the hydrocarbon distribution of the Yanqi Basin had certain relations to the characteristics of strata superface structures, and the noses of the basin stretching form secondary structural belts into depressions played an important role in the accumulation and pool-formation of hydrocarbon from source areas to traps.