东营断陷湖盆充填过程对烃源岩的控制作用研究

STUDY OF THE CONTROLLING FUNCTION OF PACKING PROCESS FOR HYDROCARBON SOURCE ROCKS

下第三系沙河街组是东营凹陷最重要的生油层段 ,精细研究发现沙河街组主力烃源岩在岩性岩相组合、有机质性质和组成等方面存在显著的差异性。通过分析盆地的沉积体系和演化序列 ,将沙河街组烃源岩自下而上划分为三个发展演化阶段 ,从湖盆形成早期的欠充填阶段经过平衡充填到最后的过充填 ,经历了一个完整的湖盆类型演变旋回过程 ,它们分别对应于岩石地层单元中的沙四上亚段、沙三下亚段和沙三中、上亚段。由于湖泊充填过程的阶段性导致了各充填单元烃源岩有机质的组成成分、有机质的保存条件和生物标志化合物等地球化学指标的差异性 ,而这些特征的差异性正说明了湖盆的充填过程控制了烃源岩的形成和发育。

The Shahejie Formation of the paleogene is the most important oil source bed in the Dongying Depression. High resolution research helps us find that there exist obvious differences in lithological combination to the characteristics and composition of organic matter. By analyzing the depositional system and the evolution series of the basin, the hydrocarbon source rocks of the Shahejie Formation can be divided into three developing periods from upper to lower. From the whole cycle of the basin's evolution: the early underpacking period, the balance period and superpacking period, they are equal to the Sha4 upper subformation, Sha3 lower subformation and Sha3 middle and lower subformation, respectively. The different stages of lacustrine packing process led to differences in geochemistry marks, such as the composition of organic matter, maintaining condition, biogenic guide compounds and so on, and these differences just show that the basin's packing process controls the formation and development of hydrocarbon source rocks.