Abstract: The first Member and second Member of the Lower Triassic Jialingjiang Formation in Luzhou Paleouplift are the main oil resources in Sichuan Basin, however, the reservoir especially the thin shoal reservoir distribution is not clear yet, which restricts oil exploration process. Based on core, cuttings and well logging data, this paper researches reservoir characteristics, reservoir genesis mechanism and paleogeomorphology, and get the following results. The reservoir lithology is mainly composed of thin-middle oolitic and bioclastic limestone, and the main reservoir space is the dissolved intragranular pores and moldic pores. The physical properties are generally poor, but high porosity and permeability layers are developed locally. The leaching of meteoric water is the main reservoir genesis mechanism, while paleouplift is the key to form reservoir by depositing grain shoals and syngenetic karstification. The well logging statistics show that the thickness of granulated rock in the first Member of Jialingjiang Formation is positively correlated with the thickness of strata, which indicates that the thickness of strata reflects the level of sedimentary palaeotopography. Therefore, it is considered that the central of Luzhou palaeouplift, the eastern margin of Kangdian palaeocontinental and the southern area of the central Sichuan palaeouplift are three main favorable areas for reservoir development. This research can be used as reference for the exploration and development of Jialingjiang Formation in Sichuan Basin, and more important it can also provide a case study for the distribution of thin shoal reservoir in the world.

Key words: carbonates, shoal facies reservoir, Jialingjiang Formation, Luzhou Paleouplift, Sichuan Basin