Abstract: This paper analyzes the petroleum geologic characteristics of the outcrop sections around Tarim basin and the Sinian in wells in this basin. It is recognized that dolomite in top of Sinian develops solution pores, vugs and fractures caused by karstification, and the reservoir pore space also contains inter-rubble pores. The effective source rocks of Sinian are argiloid of Nanhua-Sinian, mudstone and muddy limestone of Lower Cambrian which directly overlaps the Sinian dolomite reservoir as a good cap rock, forming a good reservoircap rock assemblage. The analysis of the Sinian petroleum accumulation history indicates that its top dolomite is of multistage oil-gas charging conditions, and the primary paleo-reservoir could be preserved in the paleo-uplift slope area. On this basis, integrated with regional tectonic zone evaluation, it is proposed that the Sinian strata of north slope in Tadong low swell, north side in Tazhong low swell and Keping-Bachu uplift will be favorable objectives for hydrocarbon exploration.

Key words: Tarim basin, Sinian, petroleum geology, exploration objective