在碳酸盐岩岩溶储层识别中“,串珠状”特征是十分重要的地震现象。在实际中有多种地质体可引起“串珠状”,形成机理十分复杂。本文基于理论分析,结合正演和实际资料,分析了不均匀地质体所形成的地震波场特征,多次叠加和叠前时间偏移对地震波场的影响。分析结果表明,不均匀地质体和溶洞都可以形成绕射波。在地层内部,溶洞和地层波阻抗界面的相互作用可以形成多次绕射,对这些多次波进行叠前成像,即可在垂直方向形成多个强能量团即“串珠”。因此“,串珠状”特征是多次绕射成像以后的地震现象。 The “beaded” feature in carbonate karst reservoir identification is a very important seismic phenomenon. In practice, a variety of geological bodies can cause “beaded” formation mechanism is very complicated. Based on the theoretical analysis and the combination of forward and actual data, the paper analyzes the characteristics of the seismic wave field formed by the inhomogeneous geologic bodies, the effects of multiple overlay and prestack time migration on the seismic wave field. The analysis results show that the formation of diffracted waves can be formed by uneven geologic bodies and karst caves. Inside the formation, the interaction between the karst caves and the formation impedance interface can form multiple diffraction. For prestack imaging of these multiple waves, multiple strong energy clusters, ie “beads” can be formed in the vertical direction. Therefore, the “beaded” feature is the seismic phenomenon after multiple diffraction imaging.