四川盆地川中地区须家河组储层主要为一套辫状河三角洲相砂岩，储集岩主要为长石石英砂岩、 长石岩屑砂岩和岩屑长石砂岩。以岩心观察为基础，结合薄片鉴定、扫描电镜和物性等资料分析认为，研究区砂岩经历了压实、胶结、交代、溶蚀及破裂等多种成岩作用，成岩阶段可划分为早成岩A 期、B 期和中成岩A 期、B 期4 个期次，目前已达到了中成岩阶段A—B 期。成岩作用是控制该区储层物性的一个关键因素，砂岩储层经演化后其原生孔隙大部分被破坏，主要以次生孔隙为主。

The reservoir of Xujiahe Formation in central Sichuan Basin is a set of braided river deltaic sediments, which is comprised of feldspathic quartz sandstone, feldspathic Iitharenitc sandstone and lithic feldspathic sandstone. Based on core observation, combining with thin section observation, scanning transmission electron microscope and physical property, it is believed that the sandstone in the study area experienced four diageneses: compaction, cemcntation, mctasomasis and solution. The diagenetis stage can be divided into early diagenetic A and B stage and middle diagenetic A and B stage, and nowit is in the middle diagcnetic A-B stage, The diagenesis is a key factor for controlling the physical property in this area. Most primary pores were destructed after the diagenetic evolution, so it is mainly secondary pore.