The exploration of the lower Cambrian Qiongzhusi Formation in southern Sichuan Basin shows that the shale is thin with multiple strata series

which restricts the effects of testing and pilot production. In order to further implement the favorable exploration targets and realize the benefit development of the Cambrian Qiongzhusi Formation

systematic coring

core observation and experimental analysis have been carried out. The results show that: ①Shale

siltstone（or argillaceous siltstone）

silty shale and other lithology develop in the lower Cambrian Qiongzhusi Formation in southern Sichuan Basin. Shale is relatively thin with longitudinal discontinuous deposition. ② The thermal evolution degree of shale is too high. The reservoir spaces are mainly inorganic pores

meanwhile

inorganic pores are also dominant in silty reservoir section. ③The reservoir quality of various types of lithologic combination section are similar

and they all have storage capacity. ④Drilling reveals that the siltstone-bearing shale in the middle of Qiongzhusi formation is thick with good physical and gas-bearing property

which is the favorable target interval. The research and understanding is of great significance to broaden the exploration ideas in this area.