A NEW TECHNIQUE TO MEASURE STATIC AND DYNAMIC PROPERTIES OF A PARTIALLY SATURATED POROUS-MEDIUM

A new and simple method is proposed for measuring several properties of a porous medium in the presence of two fluid phases. Although the suggested measurement is at steady-state, unlike the conventional techniques a saturation gradient is allowed to be present in the sample. In spite of this saturation gradient, it is shown that by utilizing the extended form of Darcy's law, with appropriate boundary conditions, one may obtain nonwetting phase relative permeability and by extension resistivity and saturation as a function of capillary pressure. As illustrated in this paper the advantages of the method are that it is conceptually simple to construct and operate. Furthermore, relative permeability may be obtained very close to the capillary pressure threshold. Unlike unsteady-state methods, some of which require extensive optimization procedures, the measurement is also relatively direct. The main drawback of the proposed technique is that only nonwetting phase relative permeability may be measured. An experimental apparatus that attempts to implement the proposed technique is also described. Experimental data on oil relative permeability are presented for a water-wet core to demonstrate the feasibility of the technique.