Wyniki wyszukiwania - BazTech

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Petrogeothermal energy resources within low-temperature areas of Iceland

Sowiżdżał A., Drabik A.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 4

391--401

EN

Iceland remains one of the leading countries in the field of the utilization of geothermal energy worldwide. Despite its knowledge and tremendous experience in the exploitation of mostly high-temperature geothermal energy resources (water and steam), it has been interested in the possibility of harnessing heat from hot rock formations with the implementation of the Enhanced Geothermal System (EGS). This paper presents the main outcomes of the feasibility study of EGS technology within the low-temperature area of the country. It includes broad geological research that constitutes the background for finding a suitable site for an EGS installation and to determine the local thermal parameters together with rock characteristics. To calculate the amount of heat stored within the preordained HDR formation and ascertain that the deployment of the EGS within the low temperature area of Holmavik town (NW Iceland) is plausible, the term of static resources of energy was applied. Considering the geological issue, it emerged that within the low-temperature areas of Iceland, there are excellent lithological (mainly porous lava layers) as well as thermal conditions (relatively high heat flow and geothermal gradient values) for the implementation of EGS technology for providing heat for small district heating networks. The amount of energy stored within the designed rock formation turned out to be significant and more than sufficient to cover the energy demands of Holmavik town. The authors also emphasize the importance of running several exchange programs between Polish and Icelandic research and academic centers, with the indication of possible benefits for the Polish geothermal energy sector.

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Characterization of petrophysical parameters of the Lower Triassic deposits in prospective location for Enhanced Geothermal System (central Poland)

Sowiżdżał A., Papiernik B., Machowski G., Hajto M.

Geological Quarterly

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2013

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Vol. 57, No. 4

729–-744

EN

In the years 2010-2013, analysis of rocks that build the sedimentary covers in Poland was carried out from the point of view of energy utilization accumulated in hot dry rocks – used in Enhanced Geothermal Systems (EGS). As a result of a number of analytical studies, the area situated in the central part of Poland was selected as one of prospective areas for location of EGS in sedimentary rocks. This area encompasses a major part of the Mogilno-Łódź Trough, a part of the Kujawy Swell and a small fragment of the Fore-Sudetic Monocline. The most favourable conditions for development of EGS occur in deposits of the Lower Triassic in the Krośniewice-Kutno vicinity where they are buried to depths greater than 5000 m b.s.l., have thicknesses exceeding 1500 m and are characterized by porosity about 2.5% and permeability about 0.1 mD. In the selected area, thermal characterization of the formation was carried out for location of the EGS in sedimentary rocks. The temperature at the top of Lower Triassic reservoir is in the range 165-175°C. Characterization of petrophysical parameters constituted the basis for further modelling of EGS utilization in selected area.

3

Hydraulic fracturing in systems of geothermal energy utilization (EGS, HDR)

Śliwa T., Szura M., Gonet A., Sapińska-Śliwa A.

AGH Drilling, Oil, Gas

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2012

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Vol. 29, no. 3

433--437

EN

This work reviews possibility of using the heat from impermeable hot dry rock formations. Significant development in hydraulic fracturing technique in a last few years have a result in making accessible sources of energy from impermeable rocks, including hot dry rocks, which wasn't possible before. This paper presents the idea of utilization the EGS system which is based on forced and closed water circulation in a natural and permeable geological reservoir or in a reservoir, where the fractured zone was created artificially by for example hydraulic fracturing treatment. The article shows also an examples of recent EGS/HDR systems around the world.

4

Występowanie gorących granitów w południowo – zachodnim rejonie zachodniej Litwy - nowe perspektywy dla geotermii

Sliaupa S., Motuza G., Karabliova L., Motuza V., Zaludiene G

Technika Poszukiwań Geologicznych

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2005

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R. 44, nr 3

17-25

PL

Strategia wykorzystywania energii geotermalnej na Litwie skupia się na eksploatacji zbiorników sedymentacyjnych. Alternatywnie przewidywane jest wykorzystywanie kratonicznych „gorących” granitów w technologii gorących suchych skał (ang. hot dry rock, HDR) lub wspomaganych systemów geotermalnych (ang. Enhanced Geothermal System EGS). Za najbardziej perspektywiczną w tym względzie uważa się największą (30x45 km), środkowoproterozoiczną intruzję granitoidów kratonicznych Zemaiciu Naumiestis (ZNI). Znajduje się ona w obrębie granulitów paleoproterozoicznych podłoża krystalicznego i przykryta jest osadami platformowymi o miąższości 2 km. Granitoidy kratoniczne charakteryzują się anomalną produkcją ciepła, rzędu od 4 do 19 &muW/m3, której towarzyszy wysoka gęstość strumienia cieplnego 80-100 mW/m2, co stanowi największą zmierzoną wartość na obszarze kratonu wschodnioeuropejskiego. Modelowanie pól potencjałów oraz obliczenia geotermiczne wskazują, że miąższość intruzji wynosi około 4 km (głębokość spągu 6 km). Temperatura w stropie ZNI wynosi około 95oC, co nie jest wystarczające dla wykorzystania w systemie HDR. Izoterma 150oC przewidywana jest na głębokości 3,5-4 km. Granitoidy ZNI wykazują w pewnych miejscach korzystne cechy zbiornikowe, takie jak intensywne spękania o niewielkich kątach i umiarkowanej foliacji, stąd strefy te mogą być wykorzystywane jako wspomagany zbiornik naporowy.

5

Hot granites of southwest western Lithuania: new geothermal prospects

Sliaupa S., Motuza G., Korabliova L., Motuza V., Zaludiene G.

Technika Poszukiwań Geologicznych

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2005

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R. 44, nr 3

26-34

EN

The geothermal strategy of Lithuania is focussed on the utilisation of the sedimentary geothermal aquifers. The “hot” cratonic granites are proposed as a hot dry rock (HDR) or Enhanced Geothermal System (EGS) alternative. The largest (30*45 km) Zemaiciu Naumiestis Middle Proterozoic cratonic granitoid intrusion (ZNI) hosted by the Palaeoproterozoic granulites of the crystalline basement, overlain by 2 km thick platform sediments, is suggested as the most prospective object. The cratonic granitoids are characterised by anomalous heat production ranging from 4 to 19 &muW/m3 that associates with maximum heat flow of 80-100 mW/m2 which is the highest value measured in the East European Craton. The modelling of the potential fields together with geothermal calculations indicate that the thickness of the intrusion is of about 4 km (bottom depth of 6 km). The temperature at the top of the ZNI is around 95oC that is not enough for utilisation of the HDR system. The isotherm of 150oC is predicted at the depth of 3.5-4 km. The structural features of the ZNI granitoids indicate someplace highly prospective fabrics, such as low angle intense fracturing and moderate foliation that can be utilised as the enhanced natural confined reservoir.