摘要
多次波是地震数据处理中较为常见的一种噪声干扰,对于一般厚层介质,压制多次波的方法已经较为成熟。但是在薄层介质的地震响应中,多次波成分较厚层要复杂得多,常规处理手段对薄层地震响应效果不佳,因此需要对薄层地震波传播规律和波场特征进行研究,以发展适用于薄层的地震数据处理方法。文章利用反射率法正演合成厚层和单薄层的地震记录,分析薄层与厚层地震记录中多次波场特征的区别,并计算薄层地震记录中多次波能量占反射波总能量比值与二阶以上的高阶多次波占多次波总能量比值。研究结果表明,薄层地震记录中多次波与一次波存在混叠且多次波能量占比较大,直接对多次波进行压制可能会导致有效波振幅的损失和地层信息的丢失;而多次波能量96%以上由一阶和二阶多次波贡献,二阶以上的高阶多次波在后续处理中可忽略或近似。
Multiple wave is a common noise interference in seismic data processing. For general thick layer media, the method of suppressing multiple wave has been more mature. However, in the seismic response of thin layer media, the components of multiple waves are much more complex than those in thick layers, and the effect of conventional processing methods on the seismic response of thin layers is not good, so it is necessary to study the propagation law and wave field characteristics of seismic waves in thin layers. In order to develop seismic data processing methods suitable for thin layers. In this paper, the reflectivity method is used to synthesize thick layer and single thin layer seismic records, and the difference of multiple field characteristics between thin layer and thick layer seismic records is analyzed. The ratio of multiple energy to the total energy of reflected waves in thin-layer seismic records and the ratio of higher-order multiples to total energy of multiple waves in thin-layer seismic records are calculated. The results show that there is aliasing between multiple and primary wave in thin layer seismic records, and the energy of multiple is relatively large, so the direct suppression of multiple may lead to the loss of effective wave amplitude and the loss of formation information. More than 96% of multiple energy is contributed by first-order and second-order multiples, and higher-order multiples above second-order can be ignored or approximated in subsequent processing.
出处
《科技创新与应用》
2022年第4期1-7,共7页
Technology Innovation and Application
基金
国家自然科学基金项目(U1839208,41425017)资助。
关键词
单薄层
数值分析
反射率法
多次波
正演模拟
single thin layer
numerical analysis
reflectivity method
multiple
forward simulation
