Transport Processes in Porous Media by Self-Potential Method

Abstract EN

A controlled diffusion/infiltration column experimental activity was carried out with the aim of monitoring the leakage of a salty water plume by time-lapse self-potential (SP) measurements.

In particular, three tracer tests with different NaCl concentrations (6.00, 1.00, and 0.25 g L−1) were performed and all the measured SP signals showed a sharp reduction corresponding to the arrival of saline front with negative electrical potential values (− 78.99 ± 3.24 mV, − 54.52 ± 2.28 mV, and − 24.12 ± 1.21 mV) which decrease with increasing volume of tracer introduced into the column.

Then, measured self-potential values were converted into salt concentration ones by the Planck-Henderson equation and sand diffusion ( D ) and longitudinal dispersivity ( α L ) values were estimated by modelling the transport equations in the COMSOL Multiphysics environment.

Finally, the results show that measured and estimated NaCl concentrations are well correlated.