反馈迭代法在自由表面多次波压制中的应用

Application of feedback iteration method in free surface multiple attenuation

（北京大学地球与空间科学学院，北京100871）

School of Earth and Space Sciences, Peking University, Beijing 100871, China

在地震资料处理中，多次波压制的重点是自由表面多次波。阐述了利用反馈迭代法预测并压制自由表面多次波的基本原理和实现步骤。反馈迭代法不需要地下界面信息，能够适应较复杂地下结构的情况。设计了水平海底层状介质模型和起伏海底层状介质模型，对反馈迭代法压制自由表面多次波的效果进行了试验和分析，并与抛物线拉冬变换处理结果进行了对比。结果表明，反馈迭代法在迭代次数较少的情况下就能有效地去除合成地震记录中的自由表面多次波；抛物线拉冬变换的压制效果不太理想，处理后的结果中残留有较强的自由表面多次波。

In seismic data processing, free surface multiples attenuation is important in multiples attenuation. The principles and implementations of using feedback iteration method for predicting and eliminating the free surface multiples are described. Feedback iteration method need not any information of underground interfaces and is adaptable to complex underground structures. Flat and fluctuant sea bottom layer medium model were designed and the efficiency of the feedback iteration method tested and analyzed. Compared with the processing results with parabolic Radon transform, the feedback iteration method can effectively attenuate the free surface multiples in synthetic seismic data with fewer iteration times; while the attenuation result of parabolic Radon transform is not ideal, some strong residuals of the free surface multiples still exist after processing.