Abstract: A methodology and system determine properties of a sample substance, such as a liquid/foam used to control sweep homogeneity problems in an earth formation. The methodology and system utilize a core of formation simulation material placed in a container. An injection system is coupled to the container and enables placement of both the sample substance and an injection fluid into the container. The injection fluid is injected under pressure and moves the sample substance through the core. A data acquisition system is employed to measure parameters such as pressure differentials along the core as the sample substance propagates through the formation simulation material. The pressure differentials may be evaluated over time by the data acquisition system to determine fluid breakthrough properties of the sample substance.