Qianmiqiao buried hill in Banqiao structural belt of Huanghua Depression was formed by stretch-faulting on the basis of fold-obduction.The hydrocarbon pool of the study area is a condensed oil-gas pool

the source rock is the third member of Shahejie Formation. The wax content of the crude oil is high

its methane carbon isotope could be reversed

indicating its multi-stage pool-forming origin. Gas invasion was the main cause of the pool's formation. Crude oil generated in early maturation stage migrated into the Ordoviciom reservoir of the buried hill first

then gas generated in mid maturation stage migrated in gas phase into the reservoir and formed the pool.