利用非双曲时距校正快速抽取CCP道集

转换波CCP道集的抽取及其速度分析是CCP叠加成像的重点和难点。本文提出一种快速抽取CCP道集的方法，该方法基于精确成像的转换波时距曲线公式，利用面元分割方法，快速抽取CCP道集。针对CCP道集的非对称性，利用设置虚拟震源和虚拟接收点的方法校正非双曲CCP道集。在非双曲校正后得到具有双曲时距特征的CCP道集，因此可用常规纵波处理系统完成转换波速度的分析和动校正及叠加。分别利用模型数据和实际数据抽取CCP道集和测试非双曲校正。结果表明，新方法获得的CCP道集速度谱能量团更加集中，且校正后的CCP道集同相轴更加水平，证明了本文方法的正确性，且精度更高。

CCP gather fast extraction based on non-hyperbolic time correction

One of the key points of CCP stack imaging is CCP gather extraction and its velocity analysis.With the binning method,we propose in this paper a converted-wave CCP gather fast extraction based on the accurate time-offset curve equation of converted-wave.In order to solve the asymmetry problem of CCP gathers,we correct non-hyperbolic CCP gathers with virtual sources and virtual receivers.After the correction,we obtain CCP ga-thers which show characteristics of hyperbolic time-offset curves.Thus,the velocity analysis,dynamic correction,and converted-wave stacking can be done with conventional longitudinal-wave processing system.In order to verify the accuracy of the proposed method,we test respectively the CCP gather exaction and the non-hyperbolic correction on both the model and real data.The results show that the energy of the corrected CCP gathers is more concentrated in the velocity analysis and the corrected CCP gathers are more horizontal after the normal moveout correction,which proves the correctness and the precision of the proposed method.