|RP1 – GEOTHERMAL CONDITIONS IN THE EARTH’S CRUST AND THERMO-HYDRAULIC MODELLING
The research programme (RP) No. 1 aims at increasing knowledge of geothermal conditions and thermal regime of the Earth’s crust on the territory of the Czech Republic, having in view their future utilization in projects of effective and economical use of geothermal energy. Even though Czechia is in this aspect one of the best investigated areas in Europe, it is necessary to broaden and deepen the existing knowledge for reliable predictions to be possible for the whole territory of the country.
In accordance with this, the proposed research focuses on:
1. New techniques of temperature logging and long-term temperature monitoring in boreholes (especially by means of the optic fibre DTS technique),
2. Diversifying the techniques for determining the thermal properties of rocks (especially thermal conductivity and diffusivity) and their lateral and depth variability and their dependence on temperature, pressure, mineral composition and structure,
3. Completion and expansion of the existing database of thermo-physical properties of rocks occurring in Czechia,
4. Determination/assessment of the effective thermal conductivity of a rock massif and of the effect of groundwater flow on the heat transfer in the in situ conditions of the underground laboratory,
5. Development of computational methods allowing to assess the effect of 3-D inhomogeneity of thermal conductivity and heat production of rocks on the magnitude of the heat flow/temperature gradient and
6. Analysis of the obtained results from the point of view of improvement of the heat flow map and of knowledge of the geothermal energy potential of the country.
|RP2 – INDUCED SEISMICITY AND TECTONIC STRESS
The RP2 focuses on the topic of seismic activity and slow deformation in rock environment which is associated with drilling and hydraulic stimulation of fracture permeability of rock massif with the aim to create an EGS system. RP2 further inquiries into tectonic stress, which has a direct influence on the nature of seismicity and slow deformations. An analysis of seismic and slow aseismic activity serves here to visualise deformation processes associated with fluid flows in rocks and helps to mitigate seismic effects on the Earth’s surface. To achieve this, seismic monitoring will be conducted using sensitive seismographs both on the Earth’s surface and in the boreholes as well as monitoring of slow motion on faults and on the Earth surface using dilatometers and remote sensing systems. Distinguishing between seismic and aseismic deformation of the rock environment, establishing the size and characteristics of the stimulated rock volume, its changes over time and creation of hydro-mechanical models of deformations and water flow will be the results of the research.
The team comprises researchers working in two thematic groups. Faculty of Science of Charles University is the scientific guarantor of the project and cooperates with the Institute of Geophysics and Institute of Rock Structure and Mechanics of the Czech Academy of Sciences, the Technical University of Liberec, Technical University of Ostrava and the Institute of Geonics of the Czech Academy of Science.
T.Fischer E.Káldy-Jánská J.Stemberk J.Málek F.Hartvich J.Šílený J.Maryška J.Ščučka
|RP3 – HYDROGEOLOGY AND AQUATIC GEOCHEMISTRY AND THERMO-HYDRAULIC MODELLING
The RP3 is focused on solving the hydrogeological and geochemical aspects of the project. Research of hydraulic parameters, mechanisms of formation of permeable pathways, the composition of deep fluids, and ongoing geochemical processes are essential for long-term operation of the EGS system. An important part of RP3 is a block dealing with thermal-hydraulic modelling and development and testing of new software that respects the specifics of location and geological environment. An important result of the activities RP3 will identification of risks for long-term operation of the heat exchanger resulting from relevant geochemical processes (e.g. gama-logging, encrustation and corrosive processes) and possible ways for their elimination.
It aims to:
1. Optimize hydraulic research methods to obtain data on hydro-physical parameters of rocks from the heat exchanger,
2. Ensure optimal operation of the heat exchanger and identify the risks involved, based on the research of interaction water – rock and chemical and isotopic composition of groundwater and
3. Develop and ensure experimental validation of thermal-hydraulic numerical models for optimal utilization of geothermal energy.
To meet these objectives three groups of research activities will be implemented (Hydrogeology and hydraulics, Hydro-geo-chemistry and Thermal-hydraulic modelling) that correspond to the research agenda of the above-mentioned research areas.
L.Rukavičková J.Bruthans R.Vašíček J.Maryška M.Hokr
|RP4 – GEOLOGY OF THE TARGET AREA
The RP4 focuses on geological and geodynamical aspects. The programme is of key importance for understanding the origin and development of geological units hosting the EGS system. RP4 goals comprise both enhancement of current theoretical knowledge of geodynamics with special attention to processes influencing the concentration of thermal sources in the Earth crust and development of a 4D geological model of the target locality. RP4 further concentrates on geometry and topology of fracture networks and on brittle deformation of rock masses in general, as it has direct influence on the EGS host rock permeability. At the same time, RP4 comprises work on detailed in-situ experiments concerning selected problems of geothermal energy extraction from the crystalline basement.
It aims to characterisation of the properties of the host rocks of the target area of future geothermal source in Litoměřice and its surroundings. The Important part of the research work is a 3D geological model development. This model will be used for next modelling and research works regarding possibilities of deep geothermal heat extraction. Detailed petrographic documentation of rock samples and potential adaptation of drilling strategy according to the observations and analyses of these samples are an integral part this RP.
J.Holeček J.Franěk B.Mlčoch V.Kachlík