滨海地区古近系玄武岩储集空间的充填演化研究

滨海地区位于歧口凹陷内,近年来在滨海地区古近系沙一段钻井发现多层玄武岩,并见到良好的油气显示,证实玄武岩地层是有效油气储集层。岩石学研究发现,玄武岩存在2种岩性类型：一是厚层状杏仁体发育的玄武质角砾熔岩;二是薄互层分布的具间粒结构的致密玄武岩。2种岩性储集空间存在差异,玄武质角砾熔岩内储集空间为气孔,具间粒结构的致密玄武岩内储集空间为裂缝。储集性分析认为具间粒结构的玄武岩为有效储集层,储集空间主要为晚期构造裂缝,晚期构造裂缝的形成不仅有效地沟通了下伏泥岩生油层与上覆砂岩储集层,而且也使玄武岩本身成为了油气有效储集体,后期试油也见到了良好显示。玄武岩储集性主控因素分析认为,早期充填作用对玄武岩储集空间的破坏严重,不仅在有机质成熟之前破坏了玄武质角砾熔岩内的气孔,而且也使早期、中期构造裂缝全部被充填,从而严重损害了玄武岩储层的储集性能。因此,早期充填作用是造成玄武岩储层储集性变差的主要因素。

Pore space packing and evolution of Paleogene basalt reservoir in Binhai District

Binhai District is located in Qikou Sag which is a faulted basin.In recent years,multistory basalt bodies are found in the first member of Paleogene Shahejie Formation in Binhai District.The favorable show of oil and gas has been seen,which proves that the basalt rocks are good hydrocarbon reservoir.By the petrology research,the basalt lithology can be classified into two types: thick basaltic breccia lava in which amygdaloidal structure developed and thin-interbed tight basalt with intergranular texture.Th...