Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs

4.6. Volume Translation

A comparison between the predicted liquid molar volume and the experimental data of pure compounds generally shows a systematic deviation. This deviation is approximately constant over a wide pressure range away from the critical point (Danesh, 1998). This deviation is called volume translation or volume shift parameter. The volume shift parameter can solve the weakness in molar liquid volumetric predictions by two-constant EOS. Volume translation concept was introduced by Martin in 1979. Péneloux et al. (1982) used the volume shift parameter to improve the volumetric prediction capabilities of the Soave–Redlich–Kwong EOS. They show that the volume shift parameter does not affect equilibrium calculations for pure compounds ...