The UNCONGEO project aims at predicting and quantifying the risks for the geothermal exploration activity in Switzerland associated with the presence of natural gas and oil in the subsurface. UNCONGEO - supported by the Federal Office of Energy (SFOE), the Swiss Geological Survey (Swisstopo), NAGRA and few cantons (Canton of Geneva and Canton of Vaud) - contributes substantially to the topics addressed by the SCCER-SoE associated with the challenges of deep geothermal exploration in sedimentary basins. To achieve this goal, we – a group of scientists from the University of Geneva - have applied an industry-standard petroleum system modelling approach, which integrates multidisciplinary and multiscale subsurface data using thermal modelling.
In the first phase (2017-2019), the UNCONGEO activities focused on the reconstruction of the thermal history of the Swiss Foreland Basin and to relate it with the generation, migration and accumulation of hydrocarbons. The investigation included several areas: the St. Gallen area, the Canton of Vaud, the North-eastern Switzerland area and the Canton of Geneva. The workflow comprises the reconstruction of a geological model, based on seismic and well data, the petrographic and geochemical characterization of the main petroleum system elements (source rocks, reservoirs and seals) and the definition of the potential stratigraphic and structural traps. These outcomes permit to reconstruct risk maps, which show the probability to find hydrocarbons in the subsurface in a given area.
The work carried out by this project improves the understanding of the tectonic, geodynamic and stratigraphic variables controlling the formation and distribution of hydrocarbons reserves in the Swiss Foreland Basin. We also identified the main uncertainties on the petroleum system modelling results. The project’s future activities will focus on reducing these uncertainties and on better quantifying the risk associated with the presence of hydrocarbons in specific areas of interest.