Abstract: It is indicated from drilling that Chepaizi swell is characterized by multiple oil-bearing zones, multiple reservoir types and multiple oleaginous grades. The "tri-multiple" characteristics are related to the cutting of structural framework, the control of sedimentary cycle and hydrocarbon-accumulating stage and the charging of multi-directional oil sources in terms of correlation and analysis of sedimentary strata, structural evolution and source rocks. The existence of paleo-ridge in SE direction of southern Chepaizi swell and the development of paleo-ridge in ES direction of northern Chepaizi swell allow the feature to be different, that is, in southern part the shallow Tertiary reservoir is dominated by late stage light oil accumulation and in northern part the Carboniferous-Jurassic reservoirs are characterized by heavy oil distribution and late reconstruction.

Key words: Junggar basin, Chepaizi, oil sequence, reservoir type, oleaginous grade, sedimentary cycle, structural evolution, oil source