Abstract: Based on the integral evaluation and composite study of Silurian system in Tazhong uplift, it is indicated that the long-period and stable development of the northern slope setting is favorable for the development of stratigraphic and lithologic traps, and the thin interlayer of sandstone and mudstone in tidal flat sediments is the geologic foundation for forming the lithologic trap. The multistage hydrocarbon accumulation and migration/adjustment create the framework of extensive distribution of hydrocarbons. Hence, the Silurian system in Tazhong uplift possesses the geologic conditions for shaping large-scale and low-abundance lithologic oil reservoirs. The study suggests that exploration of the Silurian must break through the idea of local structure controlling hydrocarbon accumulation. Lithologic reservoirs are the main exploration targets. The updip lithologic pinchout zone is the favorable domain for hydrocarbon accumulation. The facies-varied zone and stratigraphic onlap zone of the Silurian in eastern Tazhong area are the main directions for petroleum prospecting.

Key words: Tarim basin, Tazhong uplift, Silurian, lithological reservoir, geologic condition