Abstract: The development of buried hill of pre-Mesozoic in Yakela fault bulge was controlled mainly by Luntai and Yanan faults. The buried hill was formed in middle-late episode of Caledonian orogeny and lifted during Hercynian-Indosinian. Till the Early Cretaceous (mudstone deposit) in Yanshan movement, the buried hill-drape structure was formed completely. The multiple tectonic movements allowed shaping various buried-hill reservoirs here. The Sinian-Ordovician carbonate reservoir in it had undergone weathering and eluviation, karst process was well developed and most suitable for being as the reservoir rock. The studied area located between Kuche and Manjiaer depressions is the directing area for the long-term oil and gas migration. The unconformity and fracture system provided available passages for petroleum migration. However, the intense development of faults and the huge "scuttle" at the top of the buried hill prevent from the hydrocarbon accumulating in large scale. The study shows that the carbonate buried hill in northern Yakela structure belt (Sc2 Well) is good for re-exploration. Meanwhile, the carbonate buried hill in west section of Yakela fault bulge (Yongfengzhuang area) can be considered as the selective area for future exploration.

Key words: Tarim basin, Yakela, buried hill, carbonate rock, oil-gas migration