宽方位角地震资料噪声压制技术

宽方位角地震数据采样不满足数据采样相对均匀的要求,其主要特征为:①实际地震道相邻道之间距离小于理论道间距;②横向炮检距越大,相邻道之间距离越小,其变化率也越大,检波线的空间采样越不规则。宽方位角地震数据的上述特点导致能量较强的折射波、面波等线性噪声的时距曲线形态随着横向炮检距的增大而向双曲线变化,因此用常规线性干扰波压制技术不能完全消除线性噪声。为此,本文分析了线性时差校正联合二维傅里叶变换滤波技术及基于十字交叉排列的三维锥形滤波技术压制宽方位角线性干扰波的效果,结果表明,这两种方法可从不同角度调整地震数据的空间采样,使其变得均匀,满足不同域的转换算法对空间采样的要求,均能很好地压制宽方位角地震数据的线性噪声。

Noise attenuation technology on wide azimuth seismic data

In wide azimuth seismic data geometry,the ratio of crossline offset to inline offset is relatively large,and the spatial sampling rate of seismic data is irregular.The main features are: ① The distance between adjacent traces is less than the designed receiver interval.② The greater the crossline offset,the smaller the distance between adjacent traces,the spatial sampling rate varies rapidly with the crossline offsets.The time-distance curve of linear noise with large crossline offset,such as surface waves and refraction waves change into hyperbolic.Conventional linear noise suppression techniques,such as FK transform,are suitable only for a relative regular spatial sampling rate,but cannot completely remove the linear noises on the wide azimuth seismic data.In this article,we discuss two methods: 2-D Fourier transform filter based on linear moveout correction and 3-D conical filter based on orthogonal subset.The two methods make the spatial samples regular by different ways,which meet with the algorithm requirements of different domains.It is proved that the two methods have good results in linear noise attenua-tion on 3-D seismic data,especially on wide azimuth seismic data.