压制面波的波场分离方法

Wave field separation method for suppressing surface wave

面波是陆上地震勘探中的一种强干扰波，为了提高地震资料的信噪比和分辨率，必须在叠前对其予以压制。以往人们对面波压制方法的研究，基本上是依据面波的频率特性或视速度特性，并在实际应用中见到了一定的效果。但由于只侧重考虑面波的单一特性或在理论上基于某种数学假设，致使这些方法都会对有效波造成不同程度的损失。本文在用一定的数学方法对面波波场进行精确描述的基础上，提出了一种新的波场变换与分离方法，并成功地实现了面波波场与有效波波场的分离。该方法在压制面波的同时，可使有效波的能量（尤其是其低频能量）不受损失，有效地保持信号的频宽不变，提高记录的信噪比。实际资料的处理结果表明，本文方法是一种比较理想的叠前面波压制方法。

Surface wave is a severe noise wave in land seismic exploration. It must besuppressed before stack in order to improve the signal/noise ratio and resolution ofseismic data. Ordinary surface wave elimination methods were developed usually onthe frequency and apparent velocity characteristics of surface wave, and bring positive effect in practice. However, these methods damage effective waves in some degree because they only lay particular emphasis on a single characteristic of surfacewave or are based on a theoretic mathematic hypothesis.By describing detailedly the surface wave field in mathematic principle, we developed a new method for wave field conversion and separation, which has beenused to desirably separate off surface wave field and effective wave field. The newmethod suppresses surface wave satisfactorily: and it also avoids the loss of effective wave energy (particularly, low frequency energy), preserves the frequency band widthof signal, and raises the signal/noise ratio of seismic data. Real data results show that it is aquite good method for prestack surface wave suppression.