ESTIMATION OF ELECTROKINETIC PARAMETERS FOR ROCKS IN SINGLE-PHASE AND TWO-PHASE FLOW EXPERIMENTS

The authors has conducted experiments on estimation of electrokinetic parameters of porous permeable rocks using sandstone samples have been conducted in the regimes of stationary single-phase flow of an aqueous electrolyte solution and stationary two-phase flow of a water/kerosene mixture in a 50:50 ratio. The values of the zeta potential of the electric double layer and also of the coefficients of streaming potential and electroosmosis have been estimated. The results, on the whole, are in agreement with the known estimates obtained by traditional methods. In the two-phase flow experiments, a monotonic reduction in the electrokinetic parameters with growth in the pressure gradient was recorded on a model with the change of sign of the charge. This effect is attributed to the specific adsorption of potential-forming ions and, probably, to the partial hydrophobization of the surface of the mineral phase.