转换波地震资料中面波的压制

Suppression the ground roll in converted wave seismic data

中国矿业大学资源与安全工程学院,北京 100083

School of Resources and Safety Engineering, China University of Mining and Technology, Beijing 100083, China

转换波资料的信噪比较低,有效信号往往被面波干扰淹没,因此需要对面波进行压制,但是将面波作为线性干扰的压制方法很难得到好的效果。面波的频散和衰减以及近地表速度存在差异等特性,使得面波干扰在能量分布、道间时差和子波形态等方面都不同于数学意义上对线性同相轴的定义,更多地表现为“视”线性的特征。通过对面波能量和道间时差调整,使面波干扰更接近真正意义上的线性同相轴,可以增强利用f-k滤波压制面波的能力,在一定程度上消除面波干扰对转换波处理的影响。利用该方法对某煤田和某油田的实际转换波资料进行了处理,面波得到了有效压制,转换波从面波的干扰背景下被很好地恢复出来。

Effective suppression of ground roll is vital to converted wave seismic data processing, but the methods of suppressing ground roll, as linear noise is usually dissatisfactory. Due to dispersion and attenuation, as well as near-surface velocity variation, ground roll that is pseudo-linear is different in mathematic definition from linear event in energy distribution, moveout between traces, and waveform. The ability of f-k filter to suppress ground roll is enhanced by adjusting energy and moveout between traces so that ground roll is more close to linear event. The effect of ground roll to converted wave seismic data processing is weakened to some extent.