地震资料相位差异分析方法与应用

为了适应复杂多变的地表条件,地震采集一般采用不同的激发、接收因素联合施工,由于各种激发方式与接收方式的工作原理不同,造成了地震子波相位特征各不相同,严重影响了同相叠加效果。根据高阶统计理论,研究并实现了双谱相位重构子波提取方法,得到了具有真实相位的地震子波;对两个相同位置的地震子波进行互相关,当两个地震子波的波形完全一致时,互相关结果就表现为零相位,而当两个地震子波波形不一致时,它们的互相关结果表现为非零相位,通过确定非零相位与零相位子波的相位差异,也就确定了两地震数据之间的相位差异。研究发现:可控震源与炸药震源存在90°左右的相位差,速度检波器与压电检波器存在90°相位差,可控震源与气枪震源资料相位差异不确定。

The method and application of seismic data phase difference analysis

In order to fit diverse conditions of complex surface area, researchers usually jointly use different kinds of sources and detec-tors for acquisition. The working mode difference between various acquisition systems results in varied wavelet phases which influence the stacking effect seriously. In this paper, the accurate phase of seismic wavelet was obtained by using bispectrum based on high order statistics to reconstruct the mixed-phase spectrum of the wavelet. When there are two seismic data with complete waveform consistency, the cross-correlation result was performed as zero-phase wavelet, otherwise, it was expressed as non-zero-phase wavelet. The phase difference between the two seismic data could be determined by determining the difference between non zero-phase wavelet and zero-phase wavelet. The results show that the vibrator and explosives have 90° phase difference, the velocity detector and piezoelectric detec-tor show 90° phase difference, and the difference between air gun and vibrator is uncertain.