烃源岩排烃效率及其影响因素

烃源岩的排烃效率是油气资源评价中不可缺少的参数，排烃效率研究既可以指导资源评价，又可以作为验证资源评价结果可靠性的重要科学手段。通过新建的地层条件下排烃效率模拟实验新方法(正演)结合地质剖面法(反演)，求取了不同有机质类型烃源岩的排烃效率，并分析了热演化程度、有机质类型、有机质丰度、源储配置关系、烃源岩厚度及沉积超压对烃源岩排烃效率的影响。认为腐泥型有机质在成熟阶段的排烃效率为30%~60%；高成熟阶段的排烃效率为60%~80%，过成熟阶段的排烃效率达到80%以上。相同演化阶段，腐殖型有机质排烃效率低约10%~20%。排烃效率受多种因素的控制，预测排烃效率和滞留烃量时，不同地区应根据地质条件不同区别对待，充分考虑到各种因素的影响。

Hydrocarbon expulsion efficiency of source rocks and its influencing factors

Hydrocarbon expulsion efficiency of source rocks is an indispensable parameter in petroleum resources evaluation.The research on hydrocarbon expulsion efficiency can not only guide the evaluation of resources,but also can be used as an important scientific method to verify the reliability of resource evaluation results.A new hydrocarbon efficiency simulation experiment method under stratigraphic condition (forward) is created,this new experiment method and geologic profile method (inversion) are used to calculate the hydrocarbon efficiency of different types of hydrocarbon source rocks.What’s more,six influencing factors (degree of thermal evolution,types of organic matter,organic matter abundance,source and reservoir configuration,thickness of source rocks and sedimentary overpressure) of hydrocarbon expulsion efficiency are analyzed in the article.The hydrocarbon expulsion efficiency of the sapropelic type organic matter in the mature stage is 40%-60% and it is up to 50%-80% in the high maturity stage.At the same stage of evolution,the hydrocarbon expulsion efficiency of humic type organic matter is lower by 10%-20%.Because of hydrocarbon expulsion efficiency is controlled by many factors,so different regions should be treated differently according to different geological conditions.