LIFT去噪方法在地震资料处理中的应用

Application of LIFT denoise method in seismic data processing

（中国石油天然气股份有限公司大庆油田有限责任公司勘探开发研究院，黑龙江大庆163712）

Exploration &Development Research Institute, Daqing Oil Field Company Ltd., Daqing 163712, China

对地震资料去噪处理的效果直接影响后续处理以及资料解释的精度。以往的去噪处理方法，在提高资料信噪比的同时也损害了有效信号，不能保存原始记录中有效信号的原貌。LIFT（linear interference filter technique）去噪方法的原理是：首先从原始数据中求取信号模型道，并从原始数据中将其减掉，将噪声数据分离出来；然后对分离出来的噪声数据（含有高百分比的噪声和低百分比的有效信号）进行再次去噪处理，得到剩余数据（二次信号数据）；最后将剩余数据与信号模型道进行数据重构。对重构数据的分析表明，LIFT去噪方法不仅可以提高地震数据的信噪比，还可以最大限度地保存原始数据中的有效信号。将LIFT去噪方法应用于大庆油田实际地震资料的去噪处理，对单炮记录去噪效果的分析表明，不仅有效信号得到了很好的恢复，一些在原始数据中肉眼观察不到的噪声在分离出来的噪声记录上也被很好地显示出来；LIFT方法去噪的叠加剖面与常规方法去噪的叠加剖面的对比分析表明，用LIFT方法去噪后，噪声得到了很好的压制，资料的信噪比得到了提高，同相轴的连续性增强了，剖面上能量横向分布趋于合理。

The denoise processing of seismic data directly influence on the quality of subsequent data processing and on the accuracy of data interpretation. The former denoise methods often affect the original signals while improve S/N ratio and so cannot keep the original appearance of the effective signals. The principle of LIFT is to get the signal model trace and eliminate it from the original data so as to separate noise from the data. Then, the separated noise data is denoised again to get the residual data (the secondary signal data). Finally, the signal model traces and the residual data are reconstructed, showing that the LIFT method can not only improve the S/N ratio but also preserve the effective signal of the original data to a great extent. The application of the LIFT method in Daqing oilfield shows that the signal can be well preserved and the noise which cant be seen in the data by visual examination is clearly showed in the separated noise record. Comparison of the profiles from the LIFT method with that from the conventional denoise method indicates that the LIFT can well suppress the noise, increase the S/N ratio, and enhance the continuity of the events. As a result, the energy distribution of profile in lateral becomes more reasonable.