陆东凹陷九佛堂组火山岩屑砂岩储层影响因素分析

Analysis of Influencing Factors of Reservoir with High-Quality Volcanic Lithic Sandstone in Jiufotang Formation in Luxi Sag

摘要: 火山岩屑砂岩是外围盆地勘探中常见的岩性，相对于常规砂岩具有成熟度低、物性差等特点。本文采用岩石薄片鉴定、铸体薄片鉴定、扫描电镜分析、毛管压力曲线测定等手段，深入剖析了火山岩屑砂岩的储层特征及影响因素，认为：沉积相控制了储油岩层的形成和分布，母岩类型决定了成岩演化和蚀变性能。三角洲平原、前缘亚相具有常规低渗储层特征，前三角洲亚相具有致密油储层特征；中性火山岩的母岩类型决定了成岩演化中容易压实、碳酸盐化、溶蚀等特征；油气以赋存于颗粒溶孔中为主。这些认识将指导辽河外围其他类似区块火山岩屑砂岩的勘探。

Abstract: Volcanic lithic sandstone which has low maturity and poor physical property is usual stone in Liaohe peripheral basin. A deeply analysis on reservoir microscopic characteristics is meaningful for the next exploration and development. By a comprehensive application of rock thin-section identification, casting thin section analysis, SEM analysis, mercury-injection capillary pressure curve, and so on. The result showed that the reservoir is controlled by sedimentary facies; parent rock is the leading dominant factors. The parent rock of this sandstone is volcanic rock; it is very easily altered by carbonate and clay mineral, dissolved by organic acid, a great quantity of secondary pores were formed; the oil was sealed in debris micropores. The research will have reference significance to the next exploitation of other similar area of Liaohe depression.