关于频率电磁测深几个问题的探讨(三)——频率电磁测深相位问题分析

Analysis of frequency electromagnetic souding phase problem

频率电磁测深复电阻率含有振幅视电阻率和相位,相位既可由复电阻率的虚部和实部表示,也可通过振幅视电阻率转换得出。阐述了振幅视电阻率转换为相位的原理和计算公式。根据典型地电模型计算的振幅视电阻率曲线和相位曲线,分析了相位曲线与振幅视电阻率曲线的关系及特点。分析结果表明,相位曲线变化幅度更大,相应频率更高,可提高对地层的分辨率,加大探测地层深度。将振幅视电阻率和相位资料结合解释,可提高解释的地质效果。

The complex resistivity of frequency electromagnetic sounding contains apparent resistivity of ampli-tude and phase, the phase can be expressed by the imaginary part and the real part of the complex resistivity can also be obtained through conversion of apparent resistivity of amplitude. This paper focuses on principle and for-mula which transform the apparent resistivity of amplitude into phase. According to the typical geoelectric model the apparent resistivity of amplitude and phase have been calculated, curve characteristics and the relationship be-tween each other have been analyzed. The results display phase curves with greater amplitude and higher fre-quency. Therefore, it can improve the stratum resolution and increase the detecting depth. Through explanation combining with the data of apparent resistivity of amplitude and phase, the geological effect of the interpretation can be improved.