川西地区须家河组二段砂岩的孔隙类型主要以次生孔隙为主，其原生孔隙几乎全部被成岩作用所破坏，其中对储层孔隙发育影响最大的是压实作用、溶蚀作用、胶结作用和破裂作用等。通过对岩心、普通薄片、铸体薄片、阴极发光、碳和氧同位素、微量元素、流体包裹体等多种资料进行综合研究，阐述了主要成岩作用的形成机理和对储层孔隙发育的影响：压实作用和胶结作用是储层原生孔隙的主要破坏者，胶结作用以硅质胶结和碳酸盐胶结为主，不同成岩阶段胶结物类型不同；溶蚀作用下储层的主要储集空间为次生溶蚀孔，以长石颗粒被溶为主；破裂作用产生的裂缝能提高储层的渗透能力。

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The pore types of the second member sandstones of the Xujiahe Formation in western Sichuan are dominated by secondary pores, and the primary pores in the study area are almost completely destroyed by diagenesis. The most important diagenesis affecting the reservoir includes compaction, dissolution, cementation and fracturing action. According to the comprehensive research of various data from core, thin section, casting thin section, cathodoluminescene, carbon and oxygen isotope, trace elements, fluid inclusions etc, this paper expatiates on the formation mechanism of some major diagenesis and their corresponding products, and analyzes the influences caused by the diagenesis on the reservoir. The paper points out that compaction and cementation are the main factors that destroy the primary pores of the reservoir, and that silica cementation and carbonate cementation are the main types of cementation, and the types of cements also vary in different diagenetic stage. The main reservoir space of the dissolution typed reservoir is secondary dissolution pore which is dominated by the dissolution of feldspar grains; the fractures generated by the fracturing action can improve the permeable capacity of the reservoir.
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