A Test for Detecting Rock Property Nonuniformities in Core Samples

Abstract

Homogeneous core samples are needed for EOR experiments. We have devised a simple test for detecting the presence of nonuniformities in cores. The test consists of measuring the pressure drop across the core during a two-phase immiscible displacement experiment. We show that for a constant injection rate, the pressure drop will be linear with time provided that the core is homogeneous. In situations for which the initial section of the core is homogeneous, but the properties are not uniform in a latter section of the core, the location of the position where the rock properties first change may be approximately determined. The effect of heterogeneities on the pressure-drop profile is demonstrated with analytical solutions and laboratory experiments.