Abstract: The upper Archean buried hill of BZ gas field is dominated by metamorphic granite and gneiss, and the storage space has the characteristics of double-hole medium. The main types of reservoir space are macroscopic fractures, microscopic fractures, intergranular pores of fragmentation, and intragranular dissolved pores, etc., with strong heterogeneity, and belongs to low-porosity and ultra-low-permeability reservoirs. The buried hill of the Archean in BZ gas field is zoned longitudinally and can be classified into weathered zone and inner buried hill. The reservoir is mainly controlled by structure, paleogeomorphology, lithology and other factors.