滴南凸起区石炭系火山岩岩性特征及其意义

摘要

Based on core observation, thin section identification, petrochemical analysis and reservoir property data analysis, the characteristics and significance of Carboniferous volcanic rocks in Dinan uplift were studied. The result shows that the Carboniferous volcanic rocks in Dinan uplift have the characteristics of coexistence of basic, intermediate and acidic, and intercrescence of subalkaline and alkaline series. Basic volcanic rocks mainly are alkaline series and distributed in Dixi 17 well area. Intermediate-acidic volcanic rocks can be divided into alkaline and sub-alkaline series, the former mainly distributed in Dixi 14 and 18 well areas, and the latter mainly distributed in Dixi 17, 14 and 10 well areas. The lithology distribution on the plane has obvious zonation showing the gradual transition from basic rock to acidic rock towards the southeast. Magmatic process controls the volcanic texture, structure and matrix properties, which led to a gradual deterioration of physical properties from brecciated lava to volcanic tuff.%通过岩心观察、薄片鉴定、岩石化学及物性资料分析等,对滴南凸起区石炭系火山岩岩性特征及其意义进行了研究。结果表明：滴南凸起区石炭系火山岩具有基性、中性、酸性火山岩共存,亚碱性及碱性系列并生的特点;基性火山岩以碱性系列为主,主要分布在滴西17井区;中酸性火山岩可分为碱性和亚碱性系列2部分,前者主要分布在滴西14井区和滴西18井区,后者主要分布在滴西17井区、滴西14井区和滴西10井区;平面上,岩性分布具有明显分带性,整体呈现自西北向东南方向由基性向酸性依次过渡的特征。岩浆作用方式控制了火山岩结构、构造及基质属性,进而导致了角砾熔岩物性最优,火山凝灰岩的储集物性最差。