基于稀疏离散τ-p变换的非均匀地震道重建

Sparseness discrete τ-p transform in irregular seismic trace reconstruction.

1. 中国科学院地质与地球物理研兄所,北京100029;2. 中国科学院油气资源重点实验室,北京100029

Institute of the Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

在三维地震勘探中,地震数据的空间采样往往存在非规则化的现象,这对后续的处理,尤其是波动方程偏移,将造成很大的影响。而常规的τ-p变换由于信息不足、有限的孔径和离散等因素,使得τ-p域的结果不准确,存在假象。针对这一问题,提出了一种基于稀疏离散τ-p变换的非均匀地震道重建方法。该方法根据局部时窗内地震同相轴可以看作是一系列线性同相轴的组合的原理,使用稀疏离散τ-p变换和预条件双共轭梯度算法进行地震道重建,使空间方向不均匀采样得到规则化重建。理论计算和实际资料处理的结果表明,用该方法重建的地震道,在波形、振幅和相位等方面与原始数据拟合较好。

Irregular seismic traces caused by spatial sampling will exert influence on sequent data processing, especially on wave equation migration. The results of routine transform tend to be alias due to less information, limited aperture and discretization. Sparse-ness in the domain can supply the missing information. Sparseness discrete transform is proposed to reconstruct irregular seismic traces . It is based on the fact that the seismic profile in a window consists of some linear incidents. It enables the spatial irregular samples to be regular by reconstruction. The results of theoretic calculating and real data processing confirm that the reconstructed trace by this method fits the wave shape, amplitude and phase of raw data.