Abstract: According to the interpreted approaches of sequence stratigraphy,the lower Cretaceous strata in the northern Wuerxun sag can be divided into four types of sequence,namely simply faulted sequence,quickly faulted-depressed sequence,syngenetic faulted-depressed sequence and simply depressed sequence.Different sequences have different system tracts and petroleum potential.The development of sequences and system tracts are mainly controlled by the tectonic events,and the most favorable sequence types are the quickly faulted-depressed sequence and syngenetic faulted-depressed sequence,for they both contain best source rock,reservoir bed and caprock.

Key words: sequence stratigraphy, faulted basin, sequence type, system tracts type, oil accumulation, Wuerxun sag

摘要： 应用层序地层学解释方法对乌尔逊凹陷北部下白垩统地层进行了层序地层分析,将其划分为4个层序和4种层序类型,即简单断陷层序、快速断坳层序、同生断坳层序和简单坳陷层序。不同的层序发育有不同的体系域类型;重点分析了构造活动对这些层序和体系域类型的控制作用。在充分利用钻井、测井、地震资料的基础上建立了该地区层序地层充填模式;指出油气在这些层序和体系域类型中的赋集规律,认为快速断坳层序和同生断坳层序能形成最有利的生储盖组合。

关键词: 层序地层学, 断陷盆地, 层序类型, 体系域类型, 油气聚集, 乌尔逊凹陷