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High resource risk and upstream exploration costs are key barriers to scaling up of geothermal energy development globally. Reducing the upstream risk has, for a long time, been a priority area of the sector on several fronts. The DEEPEN project was intended to contribute to this goal through increasing the probability of success when drilling for geothermal fluids in magmatic systems. Advancement on several fronts is required for improved de-risking and in this project we address them in a targeted manner. First, there is limited understanding of the details of the interaction between the heat source, i.e., magmatic intrusions, and the geothermal system and what happens in the region between them. In this project, we develop THMC Native-State models and use them to evaluate supercritical reservoir performance. Second, many of the tools and techniques that we use for imaging geothermal systems and estimating their potential have been used for decades, with limited development. Part of this project focuses on tool development, particularly for near magmatic or super-hot resources. We develop novel geothermometers to detect whether fluids from the geothermal reservoir have at some point reached very high (>380°C) temperatures. We also explore how to best use magnetotelluric methods to image deep heat sources. Seismology, in particular seismic reflection methods, are a staple of oil and gas exploration. Unfortunately, the method is much less effective in geothermal environments. However, several seismological methods have been used in volcanology to study volcanoes and magmatic reservoirs, with some success at regional scales. For de-risking geothermal exploration, however, reservoir scale is required. As part of the DEEPEN project, we collected new seismic data to explore the feasibility of using a dense nodal network (500 nodes) together with 2 DAS units connected to fibre optic cables to image the high-temperature geothermal systems of Hengill, SW Iceland. We also collected extensive seismic and magnetotelluric data at Newberry volcano, Oregon, USA. Finally, we explore methods to jointly interpret geological, geochemical and geophysical datasets for resource estimation. This includes the development of a Play Fairway Analysis (PFA) methodology for geothermal systems in magmatic environments, with multiple plays such as conventional hydrothermal, supercritical or super-hot geothermal, and superhot Enhanced Geothermal Systems (EGS). We furthermore explore the use of multi-geophysical inversion for joint interpretation. The expected outcomes include: • a suggested site for the next super-hot well in the Iceland Deep Drilling Program series; IDDP-3, which is to be sited in one of the geothermal fields operated by OR - Reykjavík Energy in Hengill, SW Iceland • PFA method for multiple plays in magmatic environments • identification of geoscientific datasets for further research of geothermal exploration • generalized methodology for assessing supercritical resources in magmatic plays
