基于波束形成理论的组合检波技术研究

在高精度地震勘探中，常规的检波器组合接收往往不能满足保护高频信号的要求，为进一步改善地震资料品质，引入波束形成理论进行检波器组合设计，并利用信号的相关检测技术合成地震记录。针对水平层状模型，分别采用均匀加权接收和余弦加权接收合成地震记录，并定量计算了采用3,5,7单元组合接收地震记录的信噪比。数值仿真实验结果表明，随着组合检波器个数的增加，反射波信号的信噪比增大;相比于均匀加权，余弦加权获得的地震记录的平均信噪比降低了-1～1 dB，但地震记录中反射波同相轴的连续性增强了，且对有效信号的保真作用更为明显，通放带提高了16～22 Hz。

In high-precision seismic exploration,conventional geophone array often cant meet the requirement.To further improve the quality of seismic data,we applied the geophone array based on beam-forming theory and synthetized the seismic record using correlation detection technique of signals.For horizontal layered model,we applied uniform-weighting and cosine-weighting to receive and synthetize seismic record,and calculated the SNR of received seismic data using 3,5,7 combined units respectively.The theoretical result shows that the SNR of reflected waves increased along with the growth of number of combined geophones.We concluded that the average SNR of seismic record obtained by cosine-weighting varies from -1 dB to 1 dB,compared with the uniform weighting.However,the cosine-weighting geophone array could improve the continuation of the events of reflected waves in seismic record and the fidelity of the valid signals.Moreover,the band-pass increases 16~22 Hz compared with the uniform-weighting geophone array.

国家自然科学基金项目(41374123)、国家科技重大专项(2011ZX05006-002)和中国石化地球物理重点实验室开放基金项目(33550006-14-FW2099-0035)联合资助。