微地震信号的偏振—位置对比法震相分离技术

Seismic phase separation technique of micro-seismic signal by polarization-position correlation

针对微地震信号的特点,本文设计了改进的二维f-k滤波,并与自适应极化滤波相结合,提出了偏振—位置对比法追踪波的跟踪分量,实现信号的震相分离。在设计f-k滤波因子时,通过计算相邻道的滑动时窗内信号的互相关系数,确定时窗的视速度范围;在设计自适应极化滤波因子时,针对复杂波场波的期望方向不确定问题,本文通过计算相邻道的偏振投影互相关系数,确定波的跟踪分量;把常规极化滤波因子中的期望方向选为跟踪分量的方向,滤波后的信号分别向跟踪分量上进行投影,即可实现信号的震相分离。理论模型和实际资料的处理效果表明,该方法可明显改善信号分离效果。

In view of the character of seismic signal,the paper designed improved f-k filtering and presented polarization-position correlation to trace the traced component of waves in combination with adaptive polarization filtering,realizing seismic phase separation of signal. When designing the f-k filtering factor,the region of the apparent velocity in the time-window was determined by computing cross-correlation coefficient of signal in the sliding window of adjacent traces; when designing the adaptive polarization filtering factor,the paper determined the traced component of waves by computing the cross-correlation coefficient of polarization projection in adjacent traces because of uncertainty problem of waves' anticipated direction in wavefield; selecting the anticipated direction of conventional polarization filtering factor as the direction of traced component,the filtered signal was projected into traced component respectively,which achieved the seismic phase separation of signal. The theoretical model and practical data processing showed that the method is able to dramatically improve the results of signal separation.