Challenges of fluid phase behavior modeling in Iranian retrograde gas condensate reservoirs

Production from gas condensate reservoirs requires precise determination of reservoir fluid properties along with their positive impact on real reservoir performance evaluation and fluid in place volume calculation. This fact is particularly important because liquid drop out phenomena occurs as a result of pressure drop due to fluid production and condensate remains in reservoir [Mohebzadeh, 2005. In this study the challenges and problems of fluid phase behavior simulation in southern Iranian retrograde gas condensate reservoirs is discussed. Most of the problems and challenges are inaccuracy of equation of states near the critical point, special conditions and produced fluid flow constraints, sampling pressure and reservoir pressure during the sampling process, problems related to the constant composition expansion and constant volume depletion experiments, inefficiency in plus fraction characterization, problems arising from lack of the swelling test, and finally C7+ characterization.