小波变换在某气田地震剖面滤波中的应用

Application of Wavelet Transform on Seismic Section Filtering in a Gas Field

小波理论多尺度反演效果主要依赖于小波基函数的选择,不同时频的小波变换具有不同的分辨率,依据该特性对地震信号进行滤波能够有效的压制随机干扰,提高信号信噪比。以鄂尔多斯盆地北部某工区为例,针对工区内地震剖面选择不同的小波基函数进行小波阈值滤波处理,并以均方差与相似度两个参数对处理结果进行评价,找出该工区最适合的小波基函数,依此对二维地震数据进行小波包滤波。实例表明该工区db3小波阈值滤波效果最好,处理后的反射层特征变得更清晰,同相轴连续性增强,高频成分明显加强,随机噪音得到了有效压制,信噪比得到了提高。

The wavelet theoretical multi-scale inversion effect is mainly relied on the selection of wavelet basis functions.Wavelet transform of different time-frequencies have different resolutions.Based on the characteristic to carry out seismic signal filtering can suppress random interference effectively and improve signal-to-noise ratio.Taking a work area in the northern Ordos Basin as an example,aimed at seismic sections in the work area to select different wavelet basis functions carried out wavelet threshold filtering.Through mean square deviation and similarity two parameters carried out processed results assessment to find out most appropriate wavelet basis function for the work area,successively carried out 2D seismic data wavelet packet filtering.The case has shown that the work area db3 wavelet threshold filtering has best effect.The reflecting horizon characteristics after processing will be clearer,continuity of lineups enhanced,high frequencies obviously strengthened,random noises effectively suppressed,and signal-to-noise ratio improved.