| Abstract |
The International Partnership for Geothermal Technology (IPGT) provides a forum for geothermal leaders from government, industry, and academia to coordinate their efforts and collaborate on projects. The IPGT has defined a number of areas of technology focus, establishing working groups to summarize the current stateof- the-art and provide recommendations on ways to advance the technology in that area. To date, four nations have signed the IPGT charter: Australia, Iceland, Switzerland, and the United States. The Reservoir Modeling Working Group has held several workshops in member nations. The goal of the workshops were to gather information from host nation leaders in geothermal reservoir engineering and modeling regarding the simulation capabilities needed to address technical challenges facing engineered geothermal systems (EGS) and supercritical hydrothermal systems. At the workshops, input was actively solicited from geothermal industry representatives in the hope that the final list of technical challenges would also reflect the needs of professionals working in private industry. Reviewing the needs identified at the workshops and from follow-on discussions between the Working Group members, a vision of the next generation of geothermal reservoir simulators has been prepared. The vision centers on the development of a fully coupled thermo-hydro-mechanical-chemical (THMC) reservoir simulation code by the year 2020. The key strategy is a hierarchical approach, consisting of the development of laboratory and field datasets, which in turn support a series of model-component development exercises. These will focus on subsets of the full coupling that were identified as most relevant to geothermal reservoir creation and operation. The best possible conceptual and numerical approaches will be identified and implemented in order to improve the reliability and, hence, practical applicability of quantitative numerical modeling. The final code will integrate these components into a coherent simulation framework with the capabilities to describe the complex non-linear interactions and feedbacks associated with multi-phase fluid flow, energy transport, regional- and local-scale geomechanical deformation (and fracturing), and geochemical interactions between the working fluid and host reservoir rock—all at highly variable timescales. |