Abstract: The Cambrian and Ordovician are important exploration target strata in LeshanLongnvsi paleouplift area. Based on the rock core observation, thin section analysis, reservoir physical property analysis, logging and log data, the petrologic types, pore types and their configuration, distribution of porosity and permeability, reservoir types of Cambrian and Ordovician are studied in detail and discussed deeply. The results indicate: Dolomite rock is the major reservoir rock type in Cambrian and Ordovician, some limestone and sandstone occurs in the lower and middle Ordovician; various pore space types have been found, including pores, vugs and caverns and fractures, seven types of secondary dissolved pores are identified, they are intercrystal pore, intercrystal dissolved pore, interparticle dissolved pore, intraparticle dissolved pore, moldic pore and nonstructural fabric pore, the assembled patterns and distribution characteristics of the pores are different in each Formation or Member; The analysis of the combined patterns of pores, vugs and caverns, fractures proves that the vug and cavernfracture type, pore type, vug and cavern type and fracture vug and cavern type are four major reservoir types; The research results of porosity and permeability statistics also reveals that the main reservoir type of Cambrian and Ordovician is supperlow porosity and supperlow permeability reservoir, with middleporosity and lowerpermeability , lowerporosity and lowerpermeability reservoir interlayers.

Key words: paleo uplift, Cambrian, Ordovician, carbonate rocks, reservoir type, Sichuan Basin