Abstract: By means of thin section, scanning electron microscope, mercury injection and nuclear magnetism, the petrology, physical properties, reservoir space, pore throat structure and other characteristics of Shan1 and Shan2~3 reservoirs in Yan113-Yan133 well blocks were compared and studied. The results show that Shan1 reservoir is mainly composed of lithic sandstone and lithic quartz sandstone, Shan2~3 reservoir is mainly composed of quartz sandstone and lithic quartz sandstone, and Shan2~3 reservoir has higher composition and structural maturity than that of in Shanyi reservoir. Shan 1 reservoir has more cuttings dissolved pores and inter-crystalline pores, with high proportion of pore throat. Shan2~3 reservoir is mainly composed of intergranular dissolved pores with uniform pore throat structure. The significant difference between the two sets of reservoir characteristics is the result of the combined influence of sedimentary environment and diagenesis. Shan1 reservoir belongs to a continental lacustrine delta front deposit, with developed dissolution pores in the grains. Shan2~3 reservoir belongs to a marine delta front deposit, with developed intergranular dissolution pores.