六盘山盆地下白垩统沉积层序与含油气系统

Discussion on sequence stratigraphy and petroleum system of the Lower Cretaceous in Liupanshan Basin

根据露头剖面、钻井及地震资料对六盘山盆地下白垩统的沉积层序进行了剖析,把下白垩统六盘山群划分为一个沉积层序,分别由低位体系域、湖进体系域和高位体系域组成,反映了早白垩世六盘山盆地从形成、扩张、鼎盛到萎缩消亡的发展过程。探讨了六盘山盆地白垩系含油气系统的地质要素(生油层、储集层、盖层及上覆层)和作用(油气生成、运移、聚集、圈闭形成、关键时刻和保存)的发育特点,指出虽然六盘山盆地白垩系含油气系统形成的关键时刻整体上尚未到达,但在逆冲断块的下盘及断层带附近的局部构造中仍会找到白垩系含油气系统的油气藏。

Based on the sequence stratigraphic analyses of outcrops,welllogging and seismic data,one sequence can be identified from the Liupanshan Group,the Lower Cretaceous,within which LST,TST and HST were developod,reflecting the evolution of basin forming,expanding,prospering,shrinking and vanishing of Liupanshan Basin in the Early Cretaceous.The characteristics of geological elements and functions of the Cretaceous petroleum system in Liupanshan Basin are also discussed.It is pointed out that in general although the key time of the Cretaceous petroleum system in Liupanshan basin has not yet arrived at,the oil and gas pools in the Cretaceous petroleum system in Liupanshan could still be found at the underthrust or in some structural belt near the fault.