曙光—雷家地区隐蔽油气藏及其成藏动力学特征

Formation and Pool-Forming Dynamic Properties of Subtle Reservoirs in Shuguang-Leijia Area

为深化辽河西部凹陷曙光—雷家地区隐蔽油气藏勘探,根据油气勘探研究成果,结合隐蔽油气藏的分类,将研究区的隐蔽油气藏划分为前新生代潜山油气藏和古近系特殊岩性体油气藏两类。其中:前新生代潜山油气藏包括太古宇潜山油气藏,中、上元古界潜山油气藏及中生界潜山油气藏;古近系特殊岩性体油气藏包括碳酸盐岩油气藏,火山角砾岩油气藏及玄武岩油气藏。在综合研究曙光—雷家地区的地质背景、油气成藏条件及成藏过程的基础上,认为该区具有形成隐蔽油气藏优越的地质条件,如多期的构造运动、复杂的构造背景、充足的油源条件、封闭性良好的盖层和畅通、多样的油气疏导体系等。基于成藏动力学系统理论,探讨了隐蔽油气藏的动力学特征,确定古近系特殊岩性体油气藏属于自源封闭型成藏动力学系统,前新生代潜山油气藏属于它源半封闭型成藏动力学系统。研究结果表明,这两类隐蔽油气藏具有匹配良好的生烃、储层、盖层、圈闭、运移、聚集的石油地质动力学特征。

In order to speed up the hydrocarbon exploration proceeding in Shuguang-Leijia area of west depression of Liaohe basin,according to classification method of subtle reservoirs,subtle reservoirs of the area have been classified into two kinds,which are the Pre Cenozoic buried hill reservoirs and the Paleogene special lithologic reservoirs,based on the hydrocarbon exploration results.The Pre Cenozoic buried hill reservoirs include Archean buried hill reservoirs,Middle-Upper Proterozoic buried hill reservoirs and Mesozoic buried hill reservoirs.The Paleogene special lithologic reservoirs include carbonate reservoirs,volcanic breccia rock reservoirs and basalt reservoirs.Based on comprehensive study of the geological background,reservoir-forming condition and accumulation process of subtle reservoirs within the whole area,it is regarded that the geological conditions to form subtle reservoirs are favorable,such as multiple tectonic movement,complex tectonic background,favorable source conditions,cap rock with good feeling capacity,unblocked and multiple migration-accumulation systems.The characteristics of reservoir-forming dynamic is discussed according to the theory of the dynamic system for reservoir-forming.It can be clearly seen that the Paleogene special lithologic reservoirs belong to self-sourced and sealed dynamic system,and the Pre Cenozoic buried hill reservoirs belong to outward-sourced and half-sealed dynamic system.The result shows that two kinds of subtle reservoirs have the petroleum geological and dynamic characteristics of the good matching conditions of source,reservoir,cap,trap,migration and accumulation.