声电效应测井模型实验研究

模型井实验表明，在渗透性孔隙地层包围的井中发射声波时，井内不仅可以接收到声波，还可以接收到波动电场，该电场伴随声波行进，在两种不同地层的分界面处，还产生了以电磁波速度传播的电场，这两种转换电场幅度的相对大小，与地层水矿化度及其与井中水矿化度差异有关，在井中激励交变电场时，井内可以接收到声波，在用实际储层砂岩做成的模型井中，也测量了声－电转换波和电－声转换波，随着地层水矿化度增大，声－电转换信号幅度减小，电－声转换信号幅度增大。

Experimental Study on Coupled Acoustic and Electromagnetic Waves in Model Wells

Electrokinetic experiments are conducted at acoustic logging frequency in model wells with different kinds of formations. One is man made material. The other is full diameter sandstone core from target formation. We observed electric waveforms that accompany the acoustic waves in permeable formations. On the boundary between the permeable formation and another formation, there also exist acoustic waves propagating at a speed of electromagnetic waves. The relative amplitudes of these two kinds of acoustically associated electric fields depend on formation water salinity and differences of borehole fluid salinity. We also observed acoustic waves are converted from alternating electric signal in the formation. The higher the salinity, the weaker the acoustically induced electric field, and hense, the stronger the electrical induced acoustic wave.