Abstract

Recent researches have shown that there are more than four coexisting phases during CO2 or rich gas flooding. The usually implemented tree-phase flash calculation in previously developed compositional model may cause incorrect results at certain reservoir condition where the solubility of water in the crude oil substantially increases.

A four-phase fully implicit compositional reservoir simulator with four-phase flash calculation using the advanced Peng-Robinson EOS is developed. The model is to handle up to four-phase (water-rich, gas, oil and 2nd liquid) multi-component flow in porous media and simulate recovery processes such as CO2 flooding and VAPEX where four-phase flow commonly occurs.