According to the Nelson's classification scheme, naturally fractured basement reservoirs are Type 1 systems in which the fractures provide porosity and permeability. Hydrocarbon production from basement reservoirs only occurs through the connected fracture network. Thus, characterization and prediction of flow behavior in basement reservoirs is extremely difficult due to the heterogeneity of the fractures. In this study, a generalized multiphase discrete fracture network simulator was developed. The model implements 2D flow within a rectangular fracture, which is important in thick fractured reservoirs like basement rocks. The discrete fracture network model developed in this study was validated for two synthetic fracture systems using a commercial model, ECLIPSE. Comparison showed excellent agreement between the results for both models. To examine the changing production behavior in fractured basement reservoirs, an attempt was made to analyze the effect of a bottom-water aquifer on production behavior. It was confirmed that the discrete fracture network model is a useful tool in predicting water breakthrough and remaining oil phenomena.