10.5.13 Swelling Test

A swelling test is a PVT test that is used for characterization of gas injection EOR processes. In essence, a swelling test is a series of constant composition expansion tests, in each of which an increasing amount of particular injection gas is added to a reservoir oil sample at fixed temperature. In each expansion test, saturation pressure and physical and transport properties of the mixture (density and viscosity) can be determined. Swelling test data are used to optimize an equation-of-state model that properly represents phase behavior of reservoir oil and injection gas mixture at different mixing ratios.