The numerical modeling plays a fundamental role in the characterization of geological reservoirs related to the exploitation of geothermal fields and to geological storage of natural gas and CO2, and for a proper assessment of the related industrial processes, allowing to verify their technical feasibility, short and long term safety and also their economic sustainability. A specific software suite, called GeoSIAM (Integrated System for GeoModelling Analyses), has been developed and applied to simulation of CO2 geological storage, geothermal fields, natural gas geological storage and compressed air energy storage. GeoSIAM includes a number of modules, automatically connected, that allow the user to creates 3D models, simulate transient scenarios and post processing results accounting for the different typology of application field.

The system includes a WebGIS geological data base, an original modeler for the generation of static and dynamic 3D models based on finite elements, finite volumes or finite difference approaches, some modules for fluid dynamic, geomechanical and geochemical simulations at different scale of detail, and a number of tools for pre and post processing purposes, as the advanced graphic 3D visualizer and the easy-to-use interface. The goal of realizing an accurate, multipurpose and user friendly system has been satisfied also considering portability and free licensing criteria. Two examples of application are considered.

The first is devoted to characterize a geothermal field in order to verify the feasibility of a 5MWe pilot plant, while the second is devoted to verify the CO2 storage in an on-shore geological reservoir, mainly from the sealing capability point of view. In both the cases, a geological static 3D model is created and used to generate a fully 3D simulation model, including spatial mesh, petrophysical parameters and boundary conditions, after that a number of scenarios have been simulated.

The results show how the methodology implemented, together with improvements in mathematical and physical models, allows the user to perform all the items required for a geological reservoir characterization, with an high level of accuracy and accounting for similarities and peculiarities coming from the different fields of application.