层序地层格架下的含油气系统研究——开鲁盆地龙湾筒凹陷下白垩统含油气系统(!)

Research on Petroleum System Based on Sequence Stratigraphic Framework —Lower Cretaceous Petroleum System in Longwantong Sag of Kailu Basin(!)

结合地震、岩心、测井等资料 ,建立了开鲁盆地龙湾筒凹陷下白垩统等时层序地层格架 ;研究预测了各层序地层格架内沉积体系的分布。在此基础上采用含油气系统理论对该地区的油气成因、演化过程进行了研究 ,认为该凹陷下白垩统仅有一个含油气系统 ;并从层序地层学的角度剖析了该含油气系统的主力烃源岩是层序 2 (对应九佛堂组下部 )的泥岩 ,而非一般认为的整个九佛堂组 ,较好地解释了原九佛堂组上、下烃源岩在成熟度演化上的差异。此外 ,通过对含油气系统各要素的分析 ,评价了该区勘探潜力及有利的油气聚集区。

In consideration of seismic, core and well logging data, a lower Cretaceous framework of isochronous sequence stratigraphy is set up for Longwantong sag of Kailu basin, and a distribution of depositional system is studied and predicted within each sequence On the basis above, the theory of petroleum system is deployed to study the genesis and evolution of hydrocarbons in the region,which shows that there is only one petroleum system in lower Cretaceous series of the sag An analysis from the point of view of sequence stratigraphy demonstrates that the main source rock in the sag is a mud rock in sequence Ⅱ(corresponding to lower Jiufutang formation) rather than in the whole Jiufutang formation, and the differences of upper and lower source rocks of original Jiufutang formation in evolution of maturation are properly interpreted as well Exploration potentialities and favorable oil and gas accumulations are evaluated by analyzing various key factors of petroleum system