渤海湾盆地莘县凹陷原油来源及成藏主控因素

Oil source and hydrocarbon accumulation characteristics of Shenxian Sag of Bohai Bay Basin

张成富

ZHANG Chengfu

中国石化中原油田分公司勘探开发研究院，河南 濮阳 45700

Exploration and Development Research Institute, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China)

结合区域地质特征，采用族组成、色谱￣质谱、碳同位素等方法，研究了莘县凹陷原油的来源及其成藏特征。研究结果表明：渤海湾盆地莘县凹陷石炭、二叠系烃源岩饱和烃质量分数小于19%，具有植烷优势、高三环萜烷、高γ￣蜡烷、Ts＞Tm特征，形成于半咸水环境；而沙三下亚段烃源岩低成熟，饱和烃质量分数65.17%，具有低三环萜烷、低γ￣蜡烷、Ts＜Tm特征，形成于淡水环境；古近系原油为低熟油，来自于沙三下亚段的烃源岩。生烃中心是油气富集的主控因素，近源、优质储层发育区的构造调节带为下步勘探方向。

Combining geological characteristics with group composition, chromatography?鄄mass spectrometry and carbon isotopes, the crude oil and its accumulation features in the Shenxian Depression of the Bohai Bay Basin is researched. The result indicates that saturated hydrocarbon content of Carboniferous?鄄Permian hydrocarbon source rocks in the Shenxian Depression of the Bohai Bay Basin is less than 19%, and the Carboniferous?鄄Permian hydrocarbon source rocks which formed in the brackish water environment are characterized by phytane advantages, high tricyclic alkanes, high gammacerane and Ts>Tm. The lower Es3 source rocks, which formed in the freshwater environment, are characterized by low maturity, saturated hydrocarbon content about 65.17%, low tricyclic alkanes, low gammacerane and Ts

10.6056/dkyqt201905007