基于波动方程的地震波阻抗反演方法研究

地震波阻抗参数作为链接地质和地球物理的桥梁，在地质和地球物理解释中起着关键作用。地震波阻抗反演通常基于褶积概念，但是，只有波动方程才能准确描述地震波的传播机理，因此，基于波动方程的反演方法必然是地震波阻抗反演的发展趋势。由于地震数据记录的是地层介质的波阻抗变化信息，波动方程应由波阻抗来定义，这样地震反演才能获得高精度的波阻抗模型。采用傅立叶级数描述波阻抗模型，反演时既可保证波阻抗模型的空间连续性，又可实现多尺度反演策略。首先反演波阻抗的低频分量，构建波阻抗模型的背景趋势，逐级实现从低频分量到高频分量的反演，最终得到准确的波阻抗模型。针对实际地震数据的应用，一个关键技术是开展地震真波形恢复，对其低频损失进行恢复,另一个关键技术是覆盖全区域的数据分组-迭代反演策略。因此，基于波动方程的地震波阻抗反演方法研究不仅具有重要的理论科学意义而且具有有效的实际生产应用价值。

Seismic impedance parameters act as a bridge linking geology and geophysics and play a key role in geological and geophysical interpretation. Seismic impedance inversion methods are usually based on a convolution concept, but only wave equation can accurately describe the propagation mechanism of seismic waves. Thus, wave equation-based methods must be the development trend of seismic impedance inversion. Because the seismic data record the information of variations in seismic impedance in the subsurface media, the wave equation used in the inversion needs to be defined in terms of seismic impedance, so that the high-precision seismic impedance model can be obtained by seismic inversion. The seismic impedance model is parameterized by a truncated Fourier series. In this way, the inversion not only ensures the spatial continuity of the seismic impedance model but also realizes the multi-scale inversion procedure. The procedure first inverts the low-frequency components of the impedance, to reconstruct the background trend of the impedance model. Then, the procedure implements the inversion from the low-frequency components to the high-frequency components step by step, and finally produces an accurate impedance model. For the application of field seismic data, one of the key technologies is to restore the true waveform of seismic data and to recover its low frequency components, and another is the data grouping plus iterative inversion strategy which covers the entire research area. Therefore, the study of wave equation-based impedance inversion method not only has a theoretical and scientific importance but also has an effective practical application significance.