全固态组合式陆地电火花震源研制

Development of the Solid-state Modular Land Electric Spark Source

文中介绍一种新型全固态组合式陆地电火花震源。该陆地电火花震源由4台子震源组成。每台子震源采用半导体器件可控硅代替传统的三电极气体开关做放电开关,利用限流电感控制放电电流的峰值和上升时间,采用续流二极管抑制反向振荡的放电电流。通过改变放电电流波形,可以适当地改变电声转换的频谱特性。电声换能器采用的是同轴平行式电弧放电电极结构。每台子震源工作电压7 500 V时,储能为28 k J,总震源储能为112 k J。4台子震源可以同步放电或延迟放电。在河北衡水武强县进行了一次野外实验,结合地震波反射剖面和当地的地质地层数据分析得出该类型的陆地电火花震源激发的地震波勘探深度可达2 000 m以上。

This paper introduces a new type of all-solid-state land electric spark source which consists of four sub- seismic modules. Every module adopts the silicon control rectifier to replace the traditional gas switch, using the choke coil to limit the peak value and the rising-time of discharge current, using freewheeling diode to suppress re- verse oscillating discharge current. By changing the discharge current waveform,the acoustic spectrum characteris- tics can be changed produce the arc disc properly. The structure of electroacoustic transducer is a type of coaxial electrode which can harge. When the working voltage is 7 500 V,the storage of each module is 28 kJ,and the total storage will be up to 112 kJ. Four sub-seismic modules can discharge synchronously or asyn-chronously. The seis- mic section plots were obtained from the experiment in Hengshui of Hebei province. It shows that the seismic wave generated by the electric spark source can reach more than 2 000 m.