南堡凹陷的含油气系统分析

根据油岩对比分析,南堡凹陷存在两个已知的含油气系统:(1)沙河街组含油气系统;(2)东营组含油气系统。前一含油气系统在东营组沉积末时,沙河街组三段的烃源岩开始生烃,形成自生自储型原生油气藏,明化镇组沉积末,烃源岩二次生油,除形成原生油气藏外,还形成了上第三系次生油气藏;后一含油气系统在明化镇组沉积末时,东营组三段烃源岩在高柳断层以南开始生烃,形成东营组自生自储型油气藏及上第三系次生油气藏,而在高柳断层以北,烃源岩尚未开始生烃,不能形成含油气系统。因此,在南堡凹陷进行油气勘探时,高尚堡及柳赞地区,应以寻找沙河街组含油气系统的油气为主;北堡和老爷庙地区以寻找东营组含油气系统的油气为主。

ANALYSIS OF PETROLEUM SYSTEM IN NANPU SAG

According to oil source rock correlation,there are two petroleum systems in Nanpu Depression.One is Shahejie Formation petroleum system,the other one is Dongying Formation petroleum system.The source rocks of Sha 3 member of the first system began oil generation in the late stage of Dongiyng Formation,and formed self generation self reservoiring oil pools;the source rocks of the system began secondary oil generation in late Minghuazhen Formation,and formed Tertiary secondary oil pools.As for the second system,the source rocks of the third member of Dongying Formation in the south side of Gaoliu Fault started oil generation in the late stage of Minghuazhen Formation,and formed self generation self reservoiring oil pools of Dongiyng Formation and Tertiary secondary oil pools,but no hydrocarbon pools could be found in the north side of the faults.So it is suggested that hydrocarbon exploration should aimed at the petroleum system of Shahejie Formation in Gaoshangpu and Liuzan areas of the sag,and the Dongying Formation petroleum system in Beipu and Laoyemiao areas.