黄河口凹陷古近系超压发育特征及其成藏意义

沉积盆地超压普遍发育，形成机制多样，其演化过程对油气运聚成藏具有重要的影响作用。综合试油、测井资料并结合有效应力特征,分析了黄河口凹陷超压的成因机制，表明东营组超压形成受欠压实和生烃作用的共同影响，沙河街组超压成因以生烃作用为主。压力史演化数值模拟证实,构造活动控制的断层开启和砂岩夹层共同作用造成的超压释放是部分区域实测地层压力接近于常压的原因。超压发育与演化特征控制了黄河口凹陷现今不同类型油藏的垂向分布：在现今超压比较发育、未受断裂活动影响且压力释放作用不明显的区域，以寻找古近系原生油气藏为主；而在断裂沟通古近系与新近系的区域则有利于新近系次生油气藏的形成与勘探。

Development Characteristics of Overpressure and Its Accumulation Significance in Paleogene of the Huanghekou Depression

Within the sedimentary basins, overpressure is occurred widespread and the generation mechanisms are various. The overpressure evolution has significant effects on the migration and accumulation of hydrocarbon. The oil test, logging data and effective stress characteristics are integrated to analyze the overpressure genetic mechanism. The research results show that the overpressure is influenced by both undercompaction and hydrocarbon generation in Dongying Formation and the hydrocarbon generation is the major factor in Shahejie Formation. The numerical modeling results of pressure evolution history prove that the combining action of fault opening controlled by tectonic activities and interbedded sandstones is the major factor of overpressure release explaining why normal pressure exists in some regions. The development and evolution of overpressure have controls over the current vertical distribution of different types of hydrocarbon reservoirs in the Huanghekou depression. Where the overpressure is well-developed, not influenced by fault activities and not released obviously, should be for searching for the Paleogene primary hydrocarbon reservoir, and where the Paleogene has been connected with the Neogene by faults, should be priority assigned to exploring the Neogene secondary hydrocarbon reservoirs.