Accurate flow modeling of multiphase CO2/H2S systems is a primary requirement for accurate prediction and assessment of corrosion. One of the more important factors in assessing flow induced localized corrosion is determination of wall shear stress in the system. Such a determination is contingent upon accurate mapping of different flow regimes and characterization of corresponding hydrodynamic parameters. An analytical model to determine flow regimes in multiphase systems is described in this paper and is followed by a procedure to assess liquid hold-up, pressure drop and shear stress in multiphase systems. The flow modeling approach detailed has been implemented as a software program. An experimental flow loop, which may be used to simulate field conditions in the laboratory, has also been described. Keywords: Multiphase flow, modeling, wall shear stress, simulation, CO2/H2S Corrosion