Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs

2.4. Corresponding State Correlations

According to the law of corresponding states (or principle of corresponding states), all fluids with the same reduced temperature and reduced pressure have almost the same deviation from ideal gas. In other words, according to the law of corresponding states, all fluids with the same reduced temperature and reduced pressure have almost the same compressibility factor. This principle was originally stated by Van der Waals in 1873. The principle of corresponding states can be expressed in a mathematical form by Eq. (2.67)

Z=f(Tr,Pr)

(2.67)

in which Z is the compressibility factor, T_r is the reduced temperature, ...