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DEPLOYMENT OF DEEP ENHANCED GEOTHERMAL SYSTEMS FOR SUSTAINABLE ENERGY BUSINESS

Periodic Reporting for period 3 - DEEPEGS (DEPLOYMENT OF DEEP ENHANCED GEOTHERMAL SYSTEMS FOR SUSTAINABLE ENERGY BUSINESS)

Reporting period: 2018-12-01 to 2020-04-30

There is a growing need for more renewable energy in the world. Geothermal energy offers a sheer infinite resource for heat extracted from the underground, combining a constant and reliable supply with low carbon emissions. Within the EU, geothermal energy contributed in 2015 3.1% to the total primary production of renewable energy. To exploit the full potential of geothermal energy for heating and cooling, as well as for generating electricity, the EU is funding several research and demonstration projects. The focus lies on the development, improvement and demonstration of technologies for shallow and deep geothermal energy exploitation with an emphasis on safety, sustainable responsibility and cost optimisation. The DEEPEGS goal is to demonstrate the feasibility of enhanced geothermal systems (EGS) for delivering energy from renewable resources in Europe. Testing of stimulation technologies for EGS in deep wells in different geologies is meant to deliver new innovative solutions and models for wider deployments of EGS reservoirs with sufficient permeability for delivering significant amounts of geothermal power across Europe. Social feasibility studies will be carried out by integrating regulatory dimension of each country. Furthermore, to be very clear and in comfort with public acceptance, Fonroche Géothermie (FG), will not test hydrofracking in France for its projects of deep geothermal energy. Data regarding environmental hazard and risks are used to assess, analyze and prepare the work at demonstration sites. The DEEPEGS project, brings together analysis of business drivers for EGS developments on local, regional, European and global levels. The consortium partners plan to exchange best practices and develop new business strategies based on the implementations at the demonstrator sites. Further exchanges with other industry and science counterparts will be channeled into potential exploitation initiatives to create business opportunities leveraging future actions. The work to demonstrate the business cases for the various technology solutions will identify potential barriers for public acceptance, market uptake, and regulatory issues including possible standardisation needs, financing interests and other supply-side issues of relevance for successful wider EGS implementations. Objectives fulfill understanding of the deep geothermal potential by demonstrating advanced geothermal well drilling, construction, stimulation methods, reservoir engineering and modelling technologies.
The project kick-off meeting was held in Paris in December 2015 and final meeting webcast on 24 April 2020. The External Advisory Panel (EAP) has provided advice regarding the alternative site proposed in Vendenheim and participated in meetings and workshops addressing scientific outcomes from DEEPEGS.
The first DEEPEGS demonstrator at Reykjanes (WP6) drilling was was completed 25th January 2017, at 4659 m (i.e. 4650 m from surface). Supercritical conditions (426°C at 340 bar) had already been measured during drilling, 3d January 2017, at 4550 m depth after only 5-6 day heating. A perforated 7” liner was inserted down to 4591.2 m depth, and a 7” sacrificial casing from surface to 1303.7 cemented in. This was followed by deepening of the hole by 6” bit, using the 3 ½” stimulation drill string, from 4624-4636 m (pilot hole), and then by three successive spot core drilling using 6” coring tools from Baker Hughes, reaching final depth of 4659 m (i.e. 4650 m from surface). The 3 ½” stimulation string was subsequently lowered into the hole for deep stimulation. Soft stimulation by repeated heating and cooling of the lower part of the hole for a while, followed by inserting a 3 ½” drill pipes for deep stimulation which kept on going until project month 20 (July 2017). After that cold water injection kept on going until project month 33 (August 2018), followed by hot water injection until month 34. Since then the well has been allowed to heat up in preparation for discharge testing in 2019.

The second DEEPEGS demonstrator is at Vendenheim (WP7) in the Alsace region of France became part of the project in December 2018. Fonroche Geothermie (FG) had started the drilling operations in Vendenheim in June 2017.
The Rhine Graben has had several projects and experimentation done, there is still an unknown part nearby Strasbourg, where no geothermal project had been done and no project had been drilled in this region at this target’s depth of around 5 km.
Despite having some preliminary results about what the geological environment in Vendenheim form earlier available geological studies, the width of the sedimentary basin met in VDH was unknown. The bottom of this basin was 500 m deeper than anticipated and with a large Permian layer that none of the pre-existing data had predicted. The temperature reached in VDH was higher than initially anticipated (185°C) and reached a measured temperature of 225°C.
The FG seismic network had been augmented by KIT with additional seismometers, and BRGM and KIT had added Controlled-source EM and MT monitoring in the Vendenheim field. Geochemical monitoring (BRGM and FG) completed the set of survey for a better understanding of the reservoir.

DEEPEGS has produced numerous outreach and dissemination actions during its 53 months project life-cycle. The publications have been collated into a Book of Publications that can be accessed at this link; https://deepegs.eu/book-of-publications-2020/.
The project consortium will continue disseminating new results from the project and these and currently published reports will be accessible from this link; https://deepegs.eu/publications/.
The final meeting on 24 April 2020 was webcast and the recording with presentations are publicly available here; Link: https://deepegs.eu/final-meeting-outcomes/.
The main evidence that describes the progress beyond the state of the art and potential impact for the DEEPEGS project is the significant success at the demonstration site in Reykjanes Iceland. At 4659 m (i.e. 4650 m from surface) supercritical conditions (426°C at 340 bar) were confirmed.The Reykjanes well was finally ready for discharge testing in December (M49) 2019, after the original final month of DEEPEGS (M48). The DEEPEGS project had then been extended to M53 (30 April 2020). Despite strenuous efforts to discharge the well from December through March 2020, the well would not flow due to a blockage at 780 m depth. A drill rig is probably needed to open the blockage.”

In France the Vendenheim demonstration site has produced evidence of measured temperature of 225°C, which is considerably higher than expected. The well flow testing has unfortunately been delayed due to the COVID-19 pandemic in last project months in 2020. Therefore, the full results for the VDH site performance will only become available after end of the DEEPEGS project. The main socio-economic impact and societal effects and acceptance can be measured by the dissemination and communication to the industry, research institutes and universities outside the consortium. The project worked on communication to the public and how geothermal projects can be managed to minimize concerns like those commonly arising in mainland Europe about induced seismic events.