In this paper we present an integrated DDM-based hydraulic fracturing-compositional reservoir simulator that can simulate each phase in the lifecycle of a hydraulically fractured well from hydraulic fracturing to shut-in, to flowback/production and gas huff-n-puff improved oil recovery. The new model is first bench marked against our in-house fully 3-D model of a penny-shaped propagating fracture by comparing the width distribution and fracture geometry. Then, the model is used to simulate production from complex fracture networks in 3-D. The results show that the reservoir drainage area is constrained by the geometry of the fracture network. The impact of pre-existing natural fractures is investigated by propagating a hydraulic fracture with and without natural fractures and conducting production from the propagated fracture networks using the compositional simulator. The results show that: (1) natural fractures can enhance well productivity from a more compact reservoir region closer to the production well, and (2) it is important to use realistic natural fracture geometry models for history matching well production. Finally, to illustrate the model capabilities, the model is used to investigate well drawdown strategies. Results show that aggressive drawdown strategies can be used in rocks with low clay content.