可控震源定向照明方法的仿真研究

Simulation on directional illumination method of controlled source array

当野外噪声很强,即使使用组合震源地震也无法获得满意信噪比的地震数据时,本文提出了一种基于可控震源阵列的定向照明控制方法,采用该方法可形成定向地震波.通过仿真研究合成了8激震器可控震源阵列分别采用简单组合及定向照明技术得到的单炮地震记录,可以看出采用合适的延时参数,定向照明单炮地震记录的反射波信噪比高于组合地震情况.定量的计算结果表明,实验条件下采用0.89 ms延时参数,各反射波信噪比分别提高了10.19 dB,3.23 dB和1.02 dB.由此可见,可控震源定向照明地震技术是一种提高原始地震资料信噪比的有效方法.

If noise from the field is so strong that we can not get data with proper signal-to-noise ratio （SNR） even if combination source is used, we develop a directional illumination method of controlled source, which can form a directional seismic wave. We make a numeric simulation of multi-trace seismograms and computed reflected waves＇ SNR improvement when directional illumination method of controlled source array was used in given horizontal stratified model. It shows the results that SNR of reflected waves from different reflectors increase 10.19 dB, 3.23 dB, and 1. 02 dB respectively than the case of combination source when 8-unit controlled source array were used with delay time of 0.89 ms. And therefore the directional illumination control method of controlled source array is competent to improve seismic signal SNR.