The mechanism of detecting water content in oil-water emulsions using impedance spectroscopy

The water content of the oil-water emulsions has a significant impact on the flow pattern and pressure drop law of oil-water two-phase flow, thus more theory and methods are necessary to improve the detection of emulsion. Impedance spectroscopy was employed to detect oil-water emulsions with different water contents. The diffusion frequency extracted from impedance spectroscopy had a linear relationship with the water content of emulsions. In this study, polarization microscope was used to obtain the microstructure characteristics of oil-water emulsions. The increasing water content increased the logarithmic mean size of the droplets in a linear fashion. This led to an increase in the concentration of charged ions in the diffusion layer of the ionic double layer, which significantly influenced the time of the diffusion process. Consequently, impedance spectroscopy can be applied to detect the water content of emulsions and contribute to further understanding the characteristics of multi-phase flow in petroleum reservation and transportation industry.