GEOTHERMAL SYSTEMSin TRANSENERGY region

Vienna,27. 5. 2010

Andrej Lapanje, MSc. Geological Survey of Slovenia

• Geothermal systems characteristics

• Transboundary aquifers and geothermal conditions

– that is why we are here

• Overview of geothermal systems in TRANSENERGY project areaSLOVENIA AUSTRIAHUNGARY SLOVAKIA

• Final remarks

PRESENTATION TOPICS

• heat source: normal or elevated heat flow• geothermal reservoir • fluid: liquid and/or gas

• impermeable low conductive overburden• recharge

GEOTHERMAL SYSTEMS

Modified from http://iga.igg.cnr.it/geo/geoenergy.php

CLASSIFICATION OF GEOTHERMAL SYSTEMS

(Hochstein, 1988)

Low enthalpy resources < 90°C < 125°C

Intermediate enthalpy resources

90°-150°C 125°-225°C

High enthalpy resources >150°C >225°C

Geological and structural properties• depth• position• wideness• thickness• shape

Hydrogeological properties• porosity• permeability• transmissivity• static reservoir pressure• fluid mineralization• dissolved gas content

Geothermal properties• heat flow• fluid temperature

GEOTHERMAL RESERVOIRS

Muffler & Cataldi (1978); Hochstein (1990)

TRANSBOUNDARY AQUIFERS

Economic Commission for Europe: Inventory of Transboundary Ground Water in EuropeG.E. Arnold, Zs. Buzas GROUND WATER 2001. 43, no. 5: 669–678

HEAT FLOW IN TRANSENERGY REGION

Lenkey et al., 2002

Geotermalni sistemi v Sloveniji

GEOTHERMAL SYSTEMS in SLOVENIARelevant basin1. Mura-Zala basin

Maximum basin depths ~5.500m

Maximum reservoir temperatures ~200°C

Heat flow 60 -150 mW/m²Reservoir Systems: Basement, Sedimentary

Aquifers in sedimentary basins Basement aquifers beneath sedimentary basins

Tertiary sands, gravels and sandstones Fissured metamorphic Paleozoic rocks, fissured and karstified carbonate Mesozoic rocks

I II I II

25 – 60 °C < 80 °C 40 – 100 °C < 200 °C

Na-HCO3 Na-HCO3-Cl, Na-Cl Ca-Mg-HCO3, Na-HCO3-Cl, Na-Cl

Na-Cl

Low mineralization

High mineralization Low to moderate mineralization (0,5 -10g/l)

High mineralization (10-25 g/l)

Active recharge Connate water /minor recharge

Active to minor recharge

Connate water

Low gas content CO2, CH4 gas CO2 gas CO2, CH4 gas

Geothermal characteristics of Slovenia

SURFACE HEAT FLOW DENSITY - AUSTRIA

2. Vienna BasinMaximum basin depths ~7.000mMaximum reservoir temperatures ~200°CHeat flow 40-90 mW/m²Reservoir Systems: Bedrock, Sedimentary

3. Pannonian Basin (western margin)Maximum basin depths ~2.000mMaximum reservoir temperatures ~70°CHeat flow 70-110 mW/m²Reservoir Systems: Sedimentary

TRANSENERGY REGION - AUSTRIA1. Styrian Basin

Maximum basin depths ~3.500mMaximum reservoir temperatures ~130°CHeat flow 70-130 mW/m²Reservoir Systems: Bedrock, Sedimentary

Styrian Basin – hydrogeothermal overview

Goldbrunner J., 2005: Hydrogeological cross-section

Cross - section

Sedimentary reservoirs High mineralization low / no recharge Locally confined reservoirs

Bedrock reservoirs Low to moderate mineralization recharge High productivity

Preneogene Basement rocks (Styrian Basin & Mura - Zala Basin)

Moedling Block

cross - section

a)

b)

TRANSENERGY REGION - AUSTRIA2. Vienna Basin

Maximum basin depths ~7.000mMaximum reservoir temperatures ~200°CHeat flow 40-90 mW/m²Reservoir Systems: Bedrock, Sedimentary

Hydraulic barrier

Recharge area

High mineralization Connate Overpressured

Low mineralization Active recharge Temperature anomalies

Leopoldsdorf fault system

Geothermal gradient: ~5°C/100 m due to the thin litosphere → Middle Miocene back-arc style basin formation (rifting)

(Dövényi et al., 2002)

TRANSENERGY REGION - HUNGARYTemperature at a depth of 1000 m

Temperature at a depth of 2000 m

Heat flow density: 50 to 130 mW/m2

Thermal wells (T>30°C) of Hungary

high potential for intermediate and high-enthalpy resources below 1000 -1500 m

Energy content of the Upper-Pannonian-Quaternary reservoirs

(Dövényi et al., 2002)

Transenergy areas: Danube basin

Zala basin

main reservoirs

Mura-Zala basin geology

Major geothermal reservoirs: Late Miocene porous sediments

Energy content of the Mesozoic reservoirs

(Dövényi et al., 2002)

Transenergy areasKomarno Block (NE-Transdanubian Mts)

Zala basin

Major mesozoic hydrogeogical blocks of the Transdanubian Central range (after Jocha-Edelényi, 2004)

Major geothermal reservoirs: fractured-karstified mesozoic basement carbonates

SLOVAKIAGeothermal activity of selected areas expressed by surface heat flow densities

20 - Vienna Basin, 2 - Danube Basin (Central Depression), 1 - Komarno High Block, 19 - Komarno Marginal Block

Transenergy Region

Hydrogeological overview TE- SK1. Vienna Basin (Serial number of area 20)

Maximum basin depths ~6.000mMaximum reservoir temperatures ~170°CHeat flow 50-70 mW/m²Reservoir Systems: Bedrock, Sedimentary

2. Danube Basin (Central Depression) (2)Maximum basin depths ~6.000mMaximum reservoir temperatures ~200°CHeat flow 70-90 mW/m²Reservoir Systems: Sedimentary

3. Komarno High Block (1)Maximum basin depths ~3.000mMaximum reservoir temperatures ~100°CHeat flow 50-65 mW/m²Reservoir Systems: Bedrock

1.

2.

3.

4.

4. Komarno Marginal Block (19)Maximum basin depths ~2.000mMaximum reservoir temperatures ~50°CHeat flow 60-75 mW/m²Reservoir Systems: Bedrock , Sedimentary

Vienna Basin – geothermal overview

Danube Basin (Central Depression) – geothermal overview

Komarno High Block and Komarno Marginal Block – geothermal overview

Hydrogeothermal overviewVienna Basin Sedimentary BedrockTDS (g.l-1): 5 – 15 14 - 129Chemical Water Type: Na-Cl Na-ClAge of aquifer: Egenburgian TriassicAquifer lithology: clastics limestones

Danube Basin (Central Depression) Sedimentary TDS (g.l-1): 0,5 – 5 2,5 – 10 11- 125 Chemical Water Type: Na-HCO3, Na-Cl Na-ClAge of aquifer: Dacian-Pontian Pontian-Pannonian BadenianAquifer lithology: sands sands and sandstones andesites and base clastics

Komarno High Block BedrockTDS (g.l-1): 0,6 – 0,7Chemical Water Type: Ca-(Mg)-HCO3Age of aquifer: TriassicAquifer lithology: limestones, dolomites

Komarno Marginal Block Sedimentary BedrockTDS (g.l-1): 0,8 - 90 0,75 - 3,0Chemical Water Type: Ca-(Mg)-Na-HCO3-Cl, Na-Cl Ca-(Mg)-Na-SO4-Cl-HCO3Age of aquifer: Neogene Jurassic-Triassic Aquifer lithology: conglomerates and sands limestones

FINAL REMARKS

PRESENT SITUATIONVast pool of particular geognostic data in each partner stateDifferent approaches of the description of the same natural phenomena‘’White zones or border faults’’ – missing or misinterpreted geological models

of the border regionsThe transboundary character of geothermal systems is recognized –geological structures

do not stop at bordersTRANSENERGY Transboundary approach (homogenization and unification of knowledge about

geothermal systems in the region)Preparation of geognostic models (delineation and main parameter description of all

common geothermal systems)Exposition of promising areas for researchExposition of missing data to be research for

INPUT FOR THE IMPLEMENTATION TOOL