Simultaneous determination of absolute and relative permeabilities

Data from core analyses, such as residual oil saturation and relative permeabilities, are of great importance for proper exploitation of the petroleum resources. Such quantities are typically determined through interpretation of data acquired during some flooding experiment. In such determinations, the absolute permeabilities are typically represented by a single average value, i.e., the core is assumed homogeneous and isotropic. Recent studies, however, show that the validity of such assumptions can be questioned. When using such assumptions analyzing flooding data, the derived relative permeabilities will depend on the actual core sample heterogeneity, i.e., the variation and distribution of the absolute permeability in the core. A better option would therefore be to determine the absolute and relative permeabilities simultaneously from the data, thereby accounting for heterogeneity effects. In this paper we describe and test a method for such determinations, and discuss some results.