Periodic Reporting for period 2 - MEET (Multidisciplinary and multi-context demonstration of EGS exploration and Exploitation Techniques and potentials)
Reporting period: 2019-11-01 to 2021-04-30
• To capitalize on the exploitation of the widest range of fluid temperature in EGS plants and abandoned oil wells.
• To demonstrate the lower cost of small-scale production of electricity and heat in wider areas with various geological environments, in order to support a large increase of geothermal-based production sites in Europe in a near future.
• To demonstrate the viability and sustainability of EGS with electric and thermal power generation in all kinds of geological settings with 4 main types of rocks: granitic, volcanic, sedimentary and metamorphic with various degrees of tectonic overprint by faulting and folding.
MEET is taking advantage on many demo-sites and analogues sites in Europe and over the world:
• In sedimentary setting: existing oil fields in Paris and Aquitaine basins (France)
• In granitic setting: Soultz-sous-Forêts EGS power plant (France), United Downs Deep Geothermal Project (UK), Death Valley analogue (USA), an additional demo-site being under discussion in Turkey
• In volcanic setting: Grásstein well and Krauma spa both in Iceland
• In metamorphic setting: Havelange deep well (Belgium) and Göttingen University campus (Germany)
On-site operations were launched with (5) heat exchanger tested at Soultz and corrosion experiments at Cazaux, Reykjanes and Grásteinn were completed that lead to (6) choose appropriate metallurgies for ORC (Organic Rankine Cycle) heat exchangers and (7) finalize 3 first ORCs designs and (8) manufacture the mobile ORC units that (9) run for 3 to 4 months on first demonstration sites: Chaunoy oil field in France for sedimentary setting, Soultz-sous-Forêts EGS power plant in France for granitic setting and Grásteinn remote farm in Iceland for volcanic setting. In parallel (10) mapping of heat resources and needs around oil facilities lead to choose the demo-site for demonstration of heat production and (11) perform detailed implementation study, (12) obtain all necessary agreements with site owners and regulatory authorities and (13) start field works. To integrate all the results, (14) the development of a decision-making tool has been performed including major influencing factors on EGS development which (15) is in testing based on different demo-site data. In parallel, (16) an intensive review of existing GIS (Geographical Information System) dealing with geothermal energy and geodata has been completed which leads to (17) the on-going development of a web-based GIS that allows accessing a wide range of data useful for new deep geothermal project development.
Also, dissemination was quite intense with several participations to EU scientific events (conferences, workshop). A special focus was done on cross-over events by sharing best practices between oil and gas industry and geothermal industry. MEET project has been presented as a whole in several events involving a large audience in geothermal community. In October 2019 MEET successfully organized its first technical workshop and in February 2021 Geothermal Winter School has been jointly organized with the 12th European Geothermal PhD Days (EGPD).
The reinjection test done on Soultz-sous-Forêts power plant is a first achievement toward the objective of decreasing reinjection temperature from 70 to 40°C. Analyses on scaling highlight the absence of silica precipitation which was a major concern for operators in Upper Rhine Graben (URG). It also gives insights on best suited metallurgies while decreasing reinjection temperature. If generalized at all URG plants in activity, the extract heat would represent ~30MW of additional thermal capacity. A mobile ORC unit is now installed and operating on the Soultz power plant.
In addition, the ready-to-go chemical stimulation action at UDDGP site (Cornwall) is intended to demonstrate an improved production of the granitic reservoir by applying innovative chemical treatments. The stimulation strategy has been elaborated based on an important rock characterization and chemical tests performed on side-wall cores.
Thermal power and low temperature-based electric power in sedimentary basin
Within MEET project, Vermilion inventoried and analyzed thermal capacities of its whole portfolio in France. Thus, a potential over 30 MWth has been assessed on wells and oil depots disseminated over Parisian and Aquitanian basins. A review of end users led to the emergence of 6 projects to valorize heat from oil facilities. A first demonstration project in Condorcet High School has been chosen as MEET demo-site to this evolution toward the coproduction of oil and geothermal energy. Indeed, in this case, heat provided by the oil field could replace up to 90% of current energy needs of this high school.
EGS technology for non-granitic basement rocks
New and sound data sets from analogue field sites will allow, in combination with lab measurements of rock samples and advanced numerical modelling approaches, to improve existing or to develop new EGS strategies.
Demonstrate electric and thermal power generation in different geological settings
In-situ tests led to highlight what material are the most adequate for various geological conditions. These promising results and the adaptability of ORC technology used with low flow and/or low temperature show the great potential for small scale widespread electricity generation.
Mapping of EGS sites
Open access decision-making tool for deploying EGS in promising areas in Europe has been developed and is currently under testing on real case data. The core methodological concept, the general scientific content of the web-based GIS and the catalogue of relevant geothermal criteria were elaborated and finalized, always by focusing on open access data and licenses as well as availability after the end of the project lifetime.