Publication Details |
| Category | Text Publication |
| Reference Category | Conference papers |
| DOI | 10.5194/egusphere-egu22-10364 |
Licence  |
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| Title (Primary) | Monitoring of an aquifer thermal storage system in the field scale using crosshole ERT |
| Title (Secondary) | EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022 |
| Author | Birnstengel, S.; Günther, T.; Pohle, M.
; Hornbruch, G.; Nordbeck, J.; Ködel, U.; Werban, U.
; Dietrich, P.
|
| Source Titel | EGUsphere |
| Year | 2022 |
| Department | MET |
| Page From | EGU22-10364 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Abstract | Heat storage in aquifer structures takes on
greater significance and is therefore an important subject for risk assessment
and impact analysis on groundwater resources. Geophysical methods contribute
substantially to the observation of hydrogeological processes by providing
information about physical subsurface properties. In order to allow for correct
process interpretation, it is essential to find and evaluate their relationship
to the corresponding rock-physical parameters. Therefore a heat injection
experiment and a corresponding monitoring system have been developed and
established in a shallow aquifer environment characterized by quaternary
glaciofluvial sediments. The focus is on the investigation of coherence between
geophysical proxies and the temperature distribution in the near-surface. A
geological subsurface model derived from geophysical and hydrological
pre-investigations has been used to simulate heat distribution and resulting
electrical conductivity variations in the affected area. Tests for thermal
energy storage and extraction have been conducted via Aquifer thermal energy
storage (ATES) system. With time-lapse inversion we want to detect the direct
impact of changing temperature distribution in the subsurface on the related
electrical resistivity when heating the aquifer up to 80 °C. Rein et al. (2004)
state that electrical conductivity of the subsurface depends to a great extent
on water saturation. Heating up the governed pore water by 1 °C results in a
linear relative electrical conductivity increase of 2.5% (Dachnov, 1962).
Different inhole and cross- hole arrays at the test site assure good coverage
of the heated area and pass through the monitoring routine once a day. The
ongoing injection cycles consist of a heating period of 2 weeks, a down time of
3 weeks, an extraction period of 2 weeks and another down-time of 1 week
followed by the next cycle. We prove the applicability of heat injection and
extraction monitoring by combined crosshole ERT (and seismic) and correlated the
resistivity with the directly measured temperature data of the temperature
sensors additionally installed in the boreholes. At the highest observed
temperature level of 75 °C the electrical conductivity increases by a factor of
three. 3D inversion allows for a direct reference to the temperature
distribution in the subsurface. This study provides information about the
resolution capacity of crosshole ERT for heat storage systems in shallow
aquifers. These activities have been done within the follow-on TestUM-Aquifer Project - TestUM-II ”Cyclic high temperature - Aquifer thermal energy storage (ATES) experiment” funded by the BMBF (grant 03G0898A/B). |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=28189 |
| Birnstengel, S., Günther, T., Pohle, M., Hornbruch, G., Nordbeck, J., Ködel, U., Werban, U., Dietrich, P. (2022): Monitoring of an aquifer thermal storage system in the field scale using crosshole ERT EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022 EGUsphere Copernicus Publications, EGU22-10364 10.5194/egusphere-egu22-10364 |
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