延气2井区块盒8段低孔低渗储层成岩作用特征及其对储层的影响

摘要

根据常规薄片、铸体薄片、扫描电镜、X衍射等资料分析，对延气2井区块盒8段砂岩储层岩石学特征、成岩作用类型、成岩阶段划分及其对储层的影响进行了研究。结果表明：研究区盒8段储层岩石类型主要为石英砂岩、岩屑石英砂岩。研究区现今成岩作用已普遍进入晚成岩A期阶段，少量进入晚成岩B期阶段的早期。经历的成岩作用有压实作用、胶结作用、交代作用、溶蚀作用、破裂作用。其中，压实作用、胶结作用是主要的破坏性成岩作用，而溶蚀作用、破裂作用是主要的建设性成岩作用。%The data of cast slice, thin sections, scanning electron microscopy and X-diffraction were applied to analyze the petrology, diagenesis, diagenetic stage division and its effect on the reservoir of Yanqi 2 borefild in Ordos Basin. The results show that, the rock types are quartz sandstone, lithic quartz sandstone in the study area of He 8 reservoir. These sandstones have already been in stage A of the later diagenetic stage, a small amount has been in stage B of the later diagenetic stage. They experienced compaction, cementation, metasomatism, dissolution and fracturing. Among them, compaction and cementation are the main destructive diagenesis; dissolution and fracturing are major constructive diagenesis.