倍频视角的宽频地震子波优化

Optimization of broadband seismic wavelets from the perspective of octaves

宽频地震处理技术可实现数据频带的有效拓宽,提高地震资料分辨率。作为海洋地震宽频处理的主要手段,鬼波压制对水深和声速等参数较敏感,数据处理结果的频谱形态往往差异较大,给地震资料精细解释造成一定困难。为此,在充分考虑宽频数据各频率成分的能量分布前提下,提出一种倍频视角下的宽频地震子波优化方法。首先,对频率取对数,在倍频程坐标系下构建光滑的振幅谱曲线;然后,将振幅谱曲线转换到普通坐标系下,以零相位重构宽频子波,最终得到一种物理意义清晰的宽频地震子波,简称“倍频子波”。实际应用结果表明,该子波可应用于鬼波压制后的宽频地震数据的子波整形,消除因鬼波压制时参数变化引起的频谱形态差异,提高地震剖面质量。

Broadband seismic processing technology can effectively broaden the data frequency band and improve the resolution of seismic data.As one of the main means of marine broadband seismic data processing,the de-ghosting method is greatly sensitive to parameters such as water depth and the speed of sound,and the spectral morphology of data after de-ghosting is often significantly different,which makes it difficult to accurately interpret seismic data.Therefore,on the premise of fully considering the energy distribution of each frequency component of broadband data,a broadband seismic wavelet optimization method from the perspective of octaves was proposed.Firstly,the logarithm of each frequency value was taken,and a smooth amplitude spectrum curve was constructed in the octave coordinate system.Then,the curve was transformed into the ordinary coordinate system,and the broadband wavelet was reconstructed with the zero phase.Finally,a broadband seismic wavelet with clear physical meaning was obtained,which is referred to as an“octave wavelet".The practical application results show that the wavelet proposed can be applied to the wavelet shaping of broadband seismic data after de-ghosting,and it can eliminate the spectral morphological difference caused by the change in parameters during deghosting and improve the quality of seismic profiles.