【摘要】 根据陆相断陷盆地层序界面在电测曲线和地震剖面上的识别标志、岩石类型组合特点以及古生物资料等方面的特征,在苏北盆地白驹凹陷古近系共识别出6个层序界面,划分出1个超层序组、2个超层序、5个三级层序,其中SQ1、SQ2~SQ4分别为断陷Ⅰ幕初始断陷、断陷-坳陷转化阶段的湖泊层序,SQ5为断陷Ⅲ幕断陷收敛阶段的河流层序。根据盆地幕式构造演化、气候条件以及物源供给的条件不同,建立了初始断陷阶段、断陷-坳陷转换阶段和断陷收敛阶段3种层序地层充填模式,认为不同构造演化阶段的充填序列、体系域构成和砂体发育存在显著的差异。初步分析了不同层序充填演化模式与油气的关系,认为断陷Ⅰ幕的断陷-坳陷转换阶段的充填层序低位体系域和高位体系域砂体与湖侵体系域优质烃源岩配置关系最好,成藏条件最优越。更多还原

【Abstract】 Based on the identification features of stratigraphic sequences of the continental faulted basin along electric logging curves and seismic profiles as well as the characteristics of lithologic combination and palaeontological data,the authors identified six Paleogene sequence boundaries in Baiju sag of Subei basin and divided the Paleogene into one super sequence group,two super sequences,and five sequences.SQ1 and SQ2~SQ4 are lacustrine sequences developed in the initial faulting phase and faulting-depression stage of faulting episode I,while SQ5 is the fluvial sequence developed in the faulting convergence stage of faulting episode Ⅲ.Based on the episodic tectonic evolution,different climate conditions and suppy of sediments for the basin in each evolution phase,the authors established three kinds of sequence stratigraphy filling evolution models composed of initial faulting phase,faulting-depression stage and faulting convergence stage.It is thought that differenttectono-evolutionary stages have significantly different filling sequences,system tract constituents and sand body developments.A preliminary analysis was made on the relationship between sequence stratigraphic filling evolution models and oil-gas exploration potentials,which reveals that the configuration relationship between sand bodies in lowstand and highstand systems tracts and hydrocarbon source rock in lacustrine transgressive system tract of faulting-depression stage of the faulting episodeⅠ is the best in that it has the most advantageous hydrocarbon accumulation condition.更多还原