检波器组合问题的分析

Analysis on the problems of geophone array

(中国石油集团东方地球物理勘探有限责任公司采集技术支持部，河北涿州072751)

Acquisition Technical Support Department, BGP, CNPC, Zhuozhou 072751, China

关于检波器组合目前存在着几种不同的观点，归纳主要有：单点接收能否代替组合检波、检波器的点距是否越小越好、组合效应是否随炮检距变化等。针对这些问题，分别进行了讨论和分析。认为：由于数字检波器的问世和高密度采集方法的应用，单点接收采集方式在有些地区获得了较好的效果，但在低信噪比地区检波器组合仍然是提高资料质量的主要手段；通常为了保护有效信号，要求检波器组合具有较小的空间尺度，但从提高资料信噪比角度，检波器的间距并不是越小越好，组合点距和组合图形应根据噪声特点进行设计；排列长度越长检波器点距的时差就越大，可能对组合效果的影响就越大，组合基距应随排列长度变化而变化，但影响组合效果的核心因素是Δt/T(Δt为组合点距的时差，T为子波视周期)，而Δt/T随排列长度的增加变化很小，实际上对组合效果影响不大。

There exist several viewpoints about geophone array at present，including that 1) if a single receiver can replace geophone array for seismic acquisition, 2) if it is true that the smaller the geophone interval, the better, and 3) if the array effect changes with the offset, etc. Aiming at the questions, discussions and analyses were carried out. The results show that with the invention of digital geophone and application of high density acquisition, the single point receiving acquisition method has achieved good results in some area. But in the area with low S/N, the geophone array is still the main means for improving data quality. In order to protect effective signals, the geophone array is expected to be with small spatial scale. However, from the point of improving the S/N, the smaller distance of geophones is not much better; the distance between array points and array figuration should be designed according to the characteristics of noise. Longer spread length has a great moveout of geophone point distance, which seems to have a great effect on array effect. array length should change with the spread length, but the main factor affecting the array is Δt/T (here Δt is the moveout of spread point distance and T is the apparent period of wavelet). Because Δt/T has only a very small change with the increase of array length, it has little effect on the array.