相控震源地震波定向技术

Seismic beam-forming in phased array of vibroseis

针对采用多个震源同时工作的组合地震勘探,仍有所使用的震源数目受限,不适于大倾角地层勘探的问题,提出了一种产生定向地震波的方法。该方法将相控阵技术应用于可控震源阵列,通过控制相邻震源的相位差恒定,使各震源产生的地震波在某个方向上同相叠加,震动加强,形成定向的地震波束,且地震波方向、宽度可控。并从理论上分析了可控震源阵列的震源数目,空间排列方式,相差与定向地震波的关系;仿真形式给出定向地震波方向图。结果表明,采用该方法可使检波器接收信号的信噪比从组合地震的17.34dB提高到27.7dB,地震剖面图的分辨力提高17%。

Multi-vibroseis assembled seism method is limited with amount and not be able to explore steep stratum. Instead, a phased array of vibroseis is able to produce a kind of seismic beam-forming by a method of maintaining constant difference of phases between close vibroseis. With this method, different seismic waves from different vibroseis can enhance in certain direction because they are in phase. Moreover, the direction and extent of the seismic wave could be adjusted. It stated the relation between the seismic beam-forming and the number of units, the arrangement, the difference of phases for vibroseis system. Finally, it gaves out seismic beam-forming based simulation by a graph. The results show that signal-to-noise of received data can be increased from 17\^34 dB to 27\^7 dB and the ability of division for seismic section plane can be increased 17%.