点接收地震资料背景噪声的自动判别与压制

Identification and suppression of background noise on point receiver seismic data

在三分量采集或高密度单点采集中,每个地震道只用一个检波器接收,背景干扰非常严重,应用传统的去噪方法很难对其进行有效的压制。本文探讨了一种点接收地震数据压制背景噪声的新方法,处理过程分为两步,首先根据背景干扰在初至前的能量分布特征进行干扰道的判别,然后根据干扰道与正常道在频率域的不同特征,利用正常道的振幅谱包络内插出干扰道的振幅谱包络,再对干扰道频谱进行约束,压制背景散射和异常道的能量,提高资料的叠加品质。由于频率域的干扰波压制是针对干扰道进行,而且压制的是有效波的非主频段,因此具有振幅保真的特点。该方法在实际数字检波器试验资料处理中已得到成功应用。

In 3Cor high density seismic surveys,pointreceiver,viz.one sensor at a station,is often adopted.However records acquired by this approach are always dominated by background noise.This kind of noise cannot be removed substantially by conventional noise attenuation methods.We propose in this paper a new method for suppressing the background noise on point receiver data.The method includes two steps.Firstly,we identify noisy traces based on the energy distribution before the first break.Then we interpolate the amplitude spectrum envelop of the noisy trace based on the amplitude spectrum envelop of an adjacent normal trace in frequency domain.Therefore noise on the noisy trace is minimized as its spectrum envelops of noisy trace is restricted.Not only data S/N ratio is improved but also the amplitude is preserved because the suppression is done only on noisy traces and suppression frequency is out of the dominant frequency.The proposed method has been applied to field seismic data and good result has been achieved.Noise from producing wells and vehicles has been effectively suppressed and data quality of stack sections is greatly improved.