Electro-kinetic Effect Modelling

By

 Antonio Ranada Shaw¹, Kees Wapenaar¹, Evert Slob¹

(1) Delft University of Technology, 2600GA Delft, Netherlands

 In this paper we will present our last results in modeling and measuring the electro-kinetic effect. We will show a classical WRW model applied to this effect in which the sources and receivers, both electro-magnetic and seismic, are taken into account. Finally we show some fieldwork results comparable with our model.

The electro-kinetic effect represents a class of processes in which there is a conversion from electromagnetic to kinetic energy and vice versa. The interaction between seismic and electromagnetic waves is due to the relative motion of the electrically charged ions in the pore fluid when a seismic or an electromagnetic wave is passing by. The waves then generated, both seismic and electromagnetic, can be measured and provide us with information about the medium properties.

Based on a WRW approach, in which propagation, reflection and transmission of waves are represented by operators, we have developed a very general model applicable for any source-receiver geometry in a multilayered medium. Resulting from the model we see that this effect is very sensitive to the changes in the pore fluid chemistry and in the porosity between two mediums.

The applications of this model and the electro-kinetic method can go from the shallow subsurface monitoring like groundwater detection and of pollutant migration to wellbore tool and crosshole measurements. Since it is so sensitive to changes in the chemistry of the pore fluid it can be useful to determine permeable formations or monitoring multiphase flow through porous areas .