论文详情
根据地震数据中波形形态差异明显的分量对地震信号进行建模,进而构造能稀疏表示各分量的超完备字典。基于该超完备字典,实现对复杂地震信号各分量的分离。根据面波、体波的不同震荡特性,应用该方法构造不同Q值的Q可调小波函数,成功实现了体波与面波的分离。实际地震资料处理结果证明,该方法不仅能够衰减单炮地震记录中的强面波干扰噪声,同时能够更好地保护有效信号的波形特征与频谱带宽,为地震资料的后续处理和分析提供良好的基础数据;根据强背景反射连续性好等特征,考虑到河道砂体等与储层相关的地质体空间展布范围较小的特点,构造了能分别稀疏表示稳定地层及与储层相关的河道砂体等地质体地震响应的Curvelet变换原子和二维平稳小波变换原子,从而压制强屏蔽层对储层地震响应的干扰,实验结果验证了方法的有效性。
Overcomplete dictionaries can be constructed to sparsely represent targeted wave components or coherent interference based on their diverse morphologies for seismic signal analysis.This paper gives two applications of sparse representation based on overcomplete dictionaries,namely,ground-roll attenuation and interference suppression of the reservoir seismic response caused by a strong shield.For ground-roll attenuation,a low Q-factor wavelet function is constructed as the sparse representation dictionary for low-oscillatory body waves,and a high Q-factor wavelet function for high-oscillatory ground-roll.Thus,seismic data including body waves and ground-roll can be nonlinearly decomposed into low-oscillatory and high-oscillatory components.Testing on field data shows that this method can attenuate strong ground-roll noise in seismic records effectively,and preserve the waveform characteristics and spectral bandwidth of the effective signal well.For strong shield suppression,curvelet transform atoms are used to sparsely represent a strong shield,and two-dimensional stationary wavelet transform atoms are used to sparsely represent the reservoir seismic response.The results show that the method could attenuate the strong shield interference while preserving the effective reservoir seismic response.
国家自然科学基金(41774135,41504092,41504093)、中国博士后科学基金(2016T90925,2015M572567)和中央高校基本科研业务费专项资金共同资助。