Gas condensate reservoir has been demonstrated as a highly complex phase and flow properties as a result of the appearance of condensate blockage near the well-bore region. This challenge can cause a significant reduction of well productivity and even seized due to decrease in pressure around the well-bore. The reduction in the reservoir pressure could be treated by shutting in the well for a period in order to build-up the reservoir pressure. Likewise, injection fluids are preferably used to maintain the reservoir pressure above dew point to avoid retrograde condensation which can result in condensate blockage. An accurate prediction should be made to achieve informed and resourceful decisions of reservoir management and sustain well productivity. In this report, the improved productivity of hydrocarbon and maintaining the reservoir pressure of a gas condensate reservoir under water, carbon dioxide and water followed by CO2 injections were studied using ECLIPSE 300 compositional reservoir simulator for 1D, 2D and 3D models.