Lab-based experiment on real-time monitoring of underground fluid migration by self-potential measurement
Examining the scale and pathways of underground fluid migration holds significant importance in engineering leakage detection and hydrogeological investigations.As the electrokinetic effect resulting from subsurface fluid flow can induce natural charge polarization,the qualitative or quantitative interpretation of self-potential(SP)data aids in characterizing the movement of underground water flow.In this study,we constructed an indoor sandbox experiment platform with a 3D multi-channel SP measurement system.Real-time 3D SP data was collected during the imbibition process of dry quartz sand and the drainage process of saturated sand,covering the transition from unsaturated to saturated and saturated to unsaturated conditions.The experimental results demonstrate a significant correlation between the polarity characteristics of the measured SP signals and the fluid direction,consistent with the theory of the electrokinetic effect.To quantitatively interpret the experimental measured SP data,we employed the least square regularized gradient inversion algorithm,enabling the determination of streaming current density and demonstrations of water flow distribution within the tank.In addition,we conducted a similar quantitative interpretation of field SP data obtained from seepage detection in an earth-filled dam,and the recovered SP current density and fluid direction are consistent with field observations.This paper showcases the effectiveness of the SP method in monitoring seepage by comprehensively addressing the aspects of theory,method,lab-based experiments,and field data processing,highlighting the applicability of SP surveys in detecting subsurface fluid migration.
万方数据
维普
