Identification of Two-Phase Flow Regimes and Computation of Two Phase Pressure Drop in Gas Lifted Wells

Continuous gas lift process is used to boost oil production in many mature reservoirs، which can no longer produce under natural drive. In this article، application of mechanistic flow maps as well as the correlations estimating pressure drop in a gas lifted well، as the most complex and time consuming part of the gas lift modeling is examined. Using the black-oil model to compute the two-phase pressure drop in a gas lifted well leads to a substantial error due to the changes in composition and bubble point pressure along the well. In order to describe the thermodynamic behavior of the hydrocarbon fluid، a multi-component compositional description has been applied using the reduced parameter method. The results show that the empirical maps and correlations lead to severe discontinuities at transition points between the different flow regimes. This causes an unacceptable error when computing the pressure drop.