渤海湾盆地东营—沾化凹陷油气聚集的差异性及控制因素研究

DIFFERENCES OF HYDROCARBON ACCUMULATIONS IN THE DONGYING AND THE ZHANHUA DEPRESSIONS OF THE BOHAIWAN BASIN AND THEIR CONTROL FACTORS

渤海湾盆地南北紧邻的东营凹陷和沾化凹陷二者在烃源岩组成和油气藏分布等方面存在显著的差异性。东营凹陷主力烃源岩由沙四上和沙三下组成,油气藏主要分布在下第三系(占91%),以岩性、构造背斜和断块油气藏为主;沾化凹陷源岩主要由沙三、沙一段烃源岩组成,油气藏主要分布在上第三系(占90%),以潜山披覆构造油气藏为主。通过对沉降过程和断陷伸展特征的分析认为,油气分布受断陷构造运动、沉积中心迁移及有效烃源岩的控制。

Closely neighbouring in the Bohaiwan Basin, the Dongying and the Zhanhua Depressions have distinct discrepancies in the composition of hydrocarbon source rocks and the distribution of oil and gas pools. The master source rocks of the Dongying Depression consist of the Upper Sha 4 and the Lower Sha 3 Members, and the oil and gas pools mainly distributed in the Eogene(accounting for 91%)are dominated by lithological, structural anticline and fault block ones. However, the wource rocks of the Zhanhua Depression consist of the Sha 3 and the Sha 1 Members, and the oil and gas pools mainly distributed in the Neogene(accounting for 90%)are dominated by buried hill draping structure ones. The analyses of subsi dence processes and fault depression extension features showed that the distribution of hydrocarbon was controlled by fault depression tectogenesis, depocenter wandering and effective source rocks.