伸展断层是沉积盆地中的主要构造形迹。伸展断层作用不仅控制着构造圈闭的形成及沉积体系的分布 ,而且也是盆地内成熟油气垂向运移的主干通道。由伸展断层及其邻近地层中的次级断层活动产生的“地震泵”作用是油气二次运移的重要动力源之一。在复杂断块区 ,与“地震泵”所毗邻的储集层是主要的油气富集层段。在判断“地震泵”作用的层位及深度时 ,可以采用构造几何学方法与局部平衡剖面法进行综合分析。根据局部平衡剖面恢复所得到的关键油气运移期的局部伸展量变化曲线 ,可标定出某一断块区的主干伸展层段 ,确定出主干伸展层对预测油气富集的地质层位 ,据此可指导勘探目的层的优选。本文给出了应用实例 The extensional fault is the main tectonic trace in the sedimentary basin. The extension faulting not only controls the formation of structural traps and the distribution of sedimentary systems, but also is the main channel for the vertical migration of mature oil and gas in the basin. The “seismic pump” action generated by the secondary faults in the extensional fault and its adjacent strata is one of the important power sources for the secondary migration of oil and gas. In complex fault blocks, the reservoirs adjacent to the “seismic pump” are the major hydrocarbon-rich intervals. In the judgment of the “seismic pump” the role of the horizon and depth, can be used to construct the geometric method and the local equilibrium profile method for comprehensive analysis. According to the curve of the local stretch of the key hydrocarbon migration period recovered from the partial balance profile, the main stretch zone of a fault block can be calibrated, and the geological extension of the main stretch to the prediction of hydrocarbon enrichment can be determined This may guide the optimization of the target layer of exploration. This article gives an application example