Numerical simulation of geothermal reservoirs for the sustainable design of energy plants: A review.

Numerical simulation is a fundamental instrument for the elaboration and assessment of a strategic utilization of geothermal energy. It can be used for the evaluation of both the natural (unperturbed) state and the production scenarios. The motivation and important role of the numerical models are described here and deeply illustrated in the context of the geothermal energy exploitation. The mathematical-physical background is also briefly illustrated, together with all the practical problems of modeling and implementation. Particular attention must be paid to the boundary conditions and thermophysical parameters assignment and calibration. The reliability of the model must be accurately evaluated, in order to prevent common failures in design and running of the energy conversion units and wells. Several case studies are reviewed and discussed, and a final discussion is presented. The limits of the reservoir modeling and simulation are also outlined in a general methodological perspective of integrated analysis. The scenarios modeled and assessed can be then used as practical tools for the sizing and optimization of the power unit or direct heat utilization.