均衡多道1范数匹配多次波衰减的方法与应用研究

The adaptive subtraction of multiple using the equipoise multichannel L1-norm matching

反馈迭代法多次波衰减分为预测和相减两个步骤.在匹配相减过程中,当多次波和一次波同相轴不满足正交性,以及去除多次波后的地震记录不满足能量最小的情况下,最小二乘自适应匹配滤波方法不能获得正确的匹配,因此多次波的衰减产生误差.针对这两个问题,本文提出了基于1范数最小的均衡多道自适应匹配滤波法.该方法通过在空间方向上对地震记录进行均衡,避免了多次波和一次波同相轴正交的假设条件.同时利用了1范数对于大异常值保持稳健的特点,因此可以有效地解决去除多次波后的地震记录能量最小的问题.通过对模型数据和野外实际数据的多次波压制结果显示,该方法可以有效、准确地衰减多次波.

Multiple elimination using iterative inversion method includes two steps： prediction and subtraction. During matching subtraction, when multiple events are not orthogonal to primary events and the signal after multiple elimination has no minimum energy, the least-square adaptive matching filtering method can＇t get correct matching results and so multiple elimination will produce some deviation. In order to overcome the two problems above, I propose the equipoise multichannel adaptive matching filtering method using L1-norm in this paper. Through poising seismic records in the direction of space, this method avoids the assumption that multiple events are orthogonal to the primary events. Because L1-norm is robust to large amplitude differences, this method can effectively deal with the problem that the signal after multiple elimination has no minimum energy. Results of multiple suppression with simulated data and field data show that this method can effectively and correctly subtract multiples.