Possible hydrocarbon occurrences have a major impact on the prospecting and development of geothermal reservoirs as well as potential uses of the deep subsurface as sites for energy and CO2-storage. The deep subsurface of the Swiss Plateau from Lake Geneva to Lake Constance comprises a heterogeneous sedimentary succession, which documents a complex paleogeographic, climatic and tectonic history dating back around 300 million years. During this period, organic-rich formations accumulated from which hydrocarbons were generated, as revealed by several surface occurrences visible today (Roulavaz, Eclepens and others). The available data from deep reflection seismic and sparse well data, acquired mostly between the 1960s and 1980s for hydrocarbon prospection, indicate the presence of a series of tight reservoirs and source-rock intervals, at least within the main study area of the Lake Geneva basin. The series may serve as unconventional reservoirs for both oil and gas accumulations. This study evaluates the petroleum play elements of the Swiss Plateau and thus provides an independent and unbiased view on the occurrence of subsurface hydrocarbon resources within the study area, which is extrapolated to the entire Swiss Plateau.
