随机噪声的多尺度多方向域压制方法研究

Multi-scale & multi-direction suppressing method for random noise

(1.中海油田服务股份有限公司物探事业部,天津300451;2.中国石油大学(北京)油气资源与探测国家重点实验室,北京102249;3.中国石油化工股份有限公司胜利油田分公司地质科学研究院,山东东营257022;4.中国石油化工股份有限公司石油物探技术研究院,江苏南京210014)

Liu Wei,Geophysical Department,Oilfield Services Limited,CNOOC,Tianjin 300451,China

介绍了信号的多尺度多方向特性和具有此功能的第2代curvelet变换的基本原理，阐述了对于光滑且二阶连续可微的函数，第2代curvelet变换所具有的最优逼近性能。给出了地震资料随机噪声衰减的阈值方法。基于理论模型讨论了多尺度多方向域(curvelet域)的去噪特性,并将其与传统小波变换的去噪效果进行了对比。最后,将该方法应用于实际地震资料处理,结果表明,与传统小波变换相比,多尺度多方向域阈值法充分利用了信号与噪声在方向上的差异,使随机噪声得到了较好的衰减,有效提高了地震资料的信噪比,较好地保留了地震记录的有效信号。

We introduced the multi-scale & multi-direction characteristic of signal and the principles of the second generation of curvelet transform which has the multi-scale & multi-direction characteristic.According to the optimal approximation property of the second curvelet transform about smooth and second-order continuous differentiable singular function,a threshold method of random noise attenuation was proposed based on the second generation of curvelet transform.On basis of theoretical model,the suppressing effect in multi-direction domain (curvelet domain) was discussed,and was compared to that of traditional wavelet transform.Finally,our method was applied on actual data.The result shows that our method sufficiently utilized the difference of directions for signal and noise,which obtained better attenuation result for random noise,efficiently improved the S/N of seismic data,and preserved the effective signal in seismic record.