模型井声电效应的实验研究

TESTING STUDY ON ACOUSTOELECTRIC EFFECT IN MODEL BOREHOLE

在模型井中对岩石的声电效应进行了实验研究。在模型井不同矿化度条件下,同时记录声波和电磁波信号,对比分析研究电磁波的特征,结果表明,实验中记录的电磁波为声波在井孔中传播时,由于能量转换而形成的转换电磁波。瑞利波在井孔中激发了声电转换。声源激发的电磁波在频率与相位特征上不同于转换电磁波。地层水矿化度是影响转换电磁波的主要因素。

The acoustoelectric effect of rock is investigated with experimental method in model borehole. Acoustic wave and electromagnetic wave are recorded in the condition of different salinity and the characteristics of the electromagnetic wave are analyzed by comparison with acoustic wave. The study results show that the converted electromagnetic wave is induced by the acoustic wave that propagates along the borehole, and the source of the acoustoelectric conversion is Rayleigh wave in the borehole. The electromagnetic wave radiated by the acoustic source is evidently different from the converted electromagnetic wave in frequency and phase. The water salinity is a main factor influencing the amplitude of the converted electromagnetic wave.