新疆三塘湖盆地牛东区块晚石炭世—二叠纪火山岩相及储层特征

Lithofacies and reservoir characteristics of Late Carboniferous-Permian volcanic rocks in Niudong block, Santanghu Basin

详细分析了新疆三塘湖盆地牛东区块晚石炭世—二叠纪火山岩岩石类型、岩相及储层发育特征。岩石类型主要有火山碎屑岩、火山熔岩。火山碎屑岩包括凝灰岩、火山角砾岩以及火山集块岩;火山熔岩包括玄武岩、玄武安山岩。不同岩性在纵向上具有明显的韵律性,气孔玄武岩、玄武安山岩多分布于熔岩流单元的顶板和底板,中上部为杏仁玄武岩、杏仁玄武安山岩过渡带,中部及中下部为致密熔岩。顶板气孔-杏仁熔岩带和底板气孔-杏仁熔岩带原生气孔发育,气孔之间通过构造裂缝连通,是储层物性最好的岩相带之一。

The rock types, lithofacies and reservoir characteristics of Late Carboniferous-Permian volcanic rocks in Niudong block of Santanghu Basin are analyzed. The main volcanic rocks are pyroclastic rocks and lavas. The volcanic pyroclastic rocks are composed of tuff, volcanic breccia and volcanic agglomerate, while the lavas are composed of basalt and basaltic andesite. Vesicular basalt and basaltic andesite mainly distributed in roof and floor of the flow unit. It is amygdaloidal basalt and basaltic andesite in the middle and upper part, and dense basalt in the middle and lower part. The primary pore in the roof and floor of amygdaloidal lava belt developed well, which is the favorable reservoir.