This paper attempts an in-depth analysis on the hydrodynamic behavior of clays considering the multiple driving forces of pressure and induced electrical potential (IEP). Electrokinetics is employed to quantify the processes of ion migration

fluid motion

and potential distribution

which are described by the coupled equations of the Nernst-Planck (NP)

the Navier-Stokes (NS)

and the Poisson-Boltzmann (PB)

respectively. The numerical investigation shows that employment of Debye-Huckel approximation may be inappropriate for clays in calculation of double layer potential since their relatively high surface charge density. IEP is caused by the requirement of electroneutrality for the clay-water system

and is directly proportional to the separation of cation-anion resulting from the differential hydraulic migratability between them. IEP contributes to decelerating cation

accelerating anion

and producing a negative electroosmosis that counteracts in partial the positive flow driven by pressure. At those conditions including low concentration

small porosity

and high surface charge density

double layer effects may be enhanced

leading to significant effects both in IEP and its flow reduction.