Abstract
This paper describes a procedure that can be used to account for the compositional effects on phase behavior of light oils in the presence of air or flue gas. A light oil system, described by an equation of state (EOS), was used in the Amoco fully compositional model to study recovery mechanisms involved in the flue gas injection process. It was found that the interaction between the flue gas and oil contributes significantly to the production of oil and should be included in thermal simulation in some manner. The results of the compositional model were compared with another model that uses compositional dependent K-values to describe the phase distribution. The latter was accomplished by using correlations of K-values as a function of the composition of CO2 in the liquid phase. Finally, a black oil thermal simulator with constant K-values at a specific pressure and temperature was used. The fluid properties and K-values for the black oil model were obtained by matching the in-situ phase mobilities and compositions from the previous two models. The recovery responses from these three models were in close agreement, indicating that this procedure is comparable to using an EOS description.
