The EU funded project “CRM geothermal”, aims to establish an overview of the potential for raw materials in geothermal fluids for a large range of CRM elements across the EU and third countries. Due to its economic importance, Helium is closely monitored, in view of its relevance for possibly emerging digital applications [1]. Therefore, during a project-related pump test on borehole GWDD-001 of the Cornish Lithium Company in United Downs, Cornwall, UK from 20/06/2023 to 22/06/2023, an gas monitoring was conducted. This comprised the logging of gas composition and the measurement of the gas-water ratio during the pumping operation. Main focus was the examination of Helium content in the course of the pump test. In addition, experiments addressing the option of online-helium extraction via a membrane-based gas extraction method, were performed. A conventional gas sampling for lab-based analyses of bulk gas composition and noble gas concentration was completed as well. The results are reported here.
The EU funded project CRM-geothermal aims to establish an overview of the potential for critical raw materials (CRM) in geothermal fluids across the EU and third countries (Ref). Within this framework, the geothermal sites of Tuzla, Seferihisar and Dikili in eastern Turkey have been visited in March 2023. To estimate the potential of CRM at these sites, a comprehensive sampling program was performed. Rock samples (drill gravel) of the production borehole and scaling from gas-water separators were obtained. Furthermore, sampling of geothermal fluids (gas and brine) and precipitates (salt) along the production line was performed.
Here, the results of the geochemical analyses of solid sample materials (drill gravel, scales and salt) are presented.
All analyses were performed in the ElMiE-Lab (Elements and Minerals of the Earth Laboratory) at German Research Centre for Geosciences Potsdam, Germany (https://labinfrastructure.geo-x.net/laboratories/8). For their major and minor element compositions, bulk samples of drill gravel and scales were analyzed with XRF and ICP-MS, respectively. Salt precipitates were analyzed for dry loss and mineral composition using XRD.