渤海海域古近纪断裂活动对烃源岩的控制作用

Controlling effect of fault activity on source rocks during Paleogene in Bohai sea area

柴永波¹ 李伟² 刘超² 王光增² 徐珂²

中海石油（中国）天津分公司，天津 300452 中国石油大学（华东）地球科学与技术学院，山东 青岛 266580

Tianjin Branch of CNOOC Ltd., Tianjin 300452, China College of Geosciences and Technology, China University of Petroleum, Qingdao 266580, China

为了研究渤海海域断裂活动对烃源岩发育的影响，通过研究各构造阶段断裂体系的动态发育特征，结合最新的地球化学资料，得出了渤海海域烃源岩的发育和展布特征，并从不同凹陷、不同层段、不同盆地类型和不同构造带4个方面对两者的关系进行了差异性分析。结果表明：断层落差与暗色泥岩厚度、断层活动速率与源岩有机碳质量分数、构造沉降量与源岩成熟度一般具有很好的正相关性，且双向断裂控盆的盆地烃源岩发育要优于单向断裂控盆的盆地；就不同构造带而言，由缓坡带向紧邻控凹断裂的洼陷带源岩各指标具有逐渐变好的趋势。据此认为，渤海海域古近纪断裂活动对烃源岩具有很好的控制作用。

To discuss the effect of fault activity on hydrocarbon source rocks, based on the fault activity, geochemical data and predecessor research results on tectonic subsidence and source rocks of Bohai sea area, the development and distribution of source rocks in Bohai sea area are obtained, the differences of the relationship between the parameters of fault activity and hydrocarbon source rocks from different sags, strata, basin types and tectonic belts are analyzed. The result shows that the Paleogene development of source rocks is mainly controlled by fault activities in Bohai sea area, there is a good positive correlation between the fault throw and the source rock thickness, fault activity rate and organic matter percentage, present tectonic subsidence and present organic matter. Besides, source rocks in subsag belt of double-faulted graben are better than that in half-graben. For different tectonic belts, the closer to the boundary fault, the better the source rock quality. Thus, the Paleogene source rocks are chiefly controlled by fault activities in Bohai sea area.

10.6056/dkyqt201504001