渤中凹陷石南地区东营组烃源岩特征及油气勘探意义

Characteristics of Dongying Formation source rock and its significance for hydrocarbon exploration in Shinan area of Bozhong Depression

渤中凹陷石南地区东营组源岩有机质丰度高,属于中等—较好生油岩。油源对比表明,东营组源岩对研究区东营组和浅层油气成藏有重要作用。研究区构造发育演化特征表明,对于浅层油气成藏来说,在没有断层沟通深层沙河街组油源的情况下,东营组生成油气以沟通东营组油源断层以及晚期断层为主要油气运移通道,形成下生上储型油气藏,"花心"断块的油气富集程度比"花瓣"断块要高。所以,浅层油气成藏的关键是运移和圈闭的有效性。对于东营组油气成藏来说,如果圈闭和储层配置良好,也可以通过自生自储的方式捕获来自东营组成熟烃源岩生成的油气。QHD34-4构造东营组蠕虫状地震反射特征的低位域河道砂岩分布广泛,QHD35-2构造钻遇的东营组岩性圈闭含油气性好,这有可能打开渤中凹陷斜坡带东营组岩性圈闭的勘探局面。

The source rock in Dongying Formation of Shinan area in Bozhong Depression has high abundance of organic matter,which is helpful for oil and gas generation and accumulation in Dongying Formation and shallow layers.The tectonic evaluation history shows that the faults which communicated oil source rock of Dongying Formation and the latter fault are the main pathway for the reservoirs of the shallow layers if they did not connect Shahejie Formation.The oil accumulation degree is richer in the middle than that in the edge for the flower fault trap.Hydrocarbon migration pathway and the effectiveness of trap are the key factors for oil and gas accumulation in the shallow layers.If the trap has good coordination with the reservoir,Dongying Formation reservoir could get oil and gas from the oil source rock of Dongying Formation by self-accumulation and self-generation way.The lithologic reservoirs are good in oil accumulation in the QHD35-2 and QHD35-4 structures where more oil and gas resources could be found out.