Although Brazilian gas pipeline grid is already quite extensive, it continues to expand due to the Pre Salt development, since there is a growing need to increase the flowing capacity towards onshore facilities and injection wells (gas to be discarded or used for advanced oil recovery). Once pipelines are installed, maintenance operation must be performed quite often to guarantee process efficiency. Usually these operations demand depressurization from very high pressures. Considering the costs involved in such operations it is mandatory to accurately predict the total time for a complete blowdown, which may take several hours or even a couple of days. Furthermore, it is also important to evaluate the condensate content in the pipeline after the depressurization event. In the present work, a numerical model was developed to simulate gas pipeline depressurization considering unidimensional two-phase homogeneous flow. The formation and consumption of condensate from an initial supercritical state is obtained assuming phase equilibrium. Fluid properties are taken from tables generated by PVT packages. Conservation equations are discretized through the finite difference method employing Euler implicit approximation for the time derivatives and upwind scheme for spatial terms. A coupled direct algorithm was adopted to solve the resulting algebraic system. The results are compared to real field data and commercial software showing good agreement.