基于基追踪的时变子波提取与地震反射率反演

Time-variant wavelet extraction and seismic reflectivity inversion based on basis pursuit

由于噪声和衰减的影响,地震数据不平稳,即地震信号的频谱从浅到深是逐渐变化的。为了研究地震数据的非平稳性质,基于基追踪谱分解方法进行高分辨率时频分解,通过点谱模拟提取广义地震子波,继而构建时变子波核矩阵和时变子波字典,最终实现非平稳基追踪地震反演。实际资料测试表明,基追踪谱分解广义时变子波提取方法能实现高效井震标定,基于时变子波的非平稳基追踪地震反演结果分辨率更高、地质连续性更强、地质细节展示更详细。

Seismic data are nonstationary because of noise contamination and energy attenuation during wave propagation, which means that the frequency spectrum of seismic signals changes from shallow to deep formations. In order to capture the non-stationary of seismic data, a time-variant wavelet extraction method is proposed using basis pursuit spectral decomposition and generalized seismic wavelet, in which basis pursuit spectral decomposition would supply high resolution time-frequency spectrum for better time-variant wavelet extraction. Based on time-variant wavelets, wavelet kernel matrix and wave dictionary are constructed, and basis pursuit seismic inversion is executed at last. Field data test shows that the proposed scheme achieves better data resolution, more effective wellto- seismic calibration, better geological continuity, and clearer geological details.