In this project, it is proposed to build a next generation, interacting systems models for simulation of production from naturally fractured reservoirs, such as Kazakhstan’s massive Caspian reservoirs, Kashagan and Tengiz. This model will reduce the computational burden in simulating this class of complex reservoir and enable better reservoir management decision-making through improved characterization and lowered risk. The research product could be considered a fast computing engine for use in large optimization routines, not possible with traditional numerical reservoir simulators. It could also be embedded within a numerical model to capture subscale information without the grid refinement requirement, thereby improving the capacity of numerical reservoir simulators. Additionally, the model will be used to generate new well test analyses for subsurface property evaluation and improved reservoir characterization.