| Title | Structural outline, depositional setting and assessment of Mesozoic low enthalpy geothermal aquifers in the marginal eastern parts of the Danish Basin |
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| Authors | Erlström, Bidstrup, Lindström, Nielsen, Kristensen, Mathiesen |
| Year | 2013 |
| Conference | European Geothermal Conference |
| Keywords | Subsurface characterization, Mesozoic, geothermal reservoirs, Øresund Sub-Basin |
| Abstract | The subsurface geology in the transnational Øresund area between Sweden and Denmark is composed of a 2 000–3 500 m thick sequence of Phanerozoic strata. The Øresund region, centred on the cities of Copenhagen and Malmö is the most densely populated area in Scandinavia. In the range of 3.8 million people work and live in the region. In spite of the fact that there are suitable geological as well as socio-economic prerequisites geothermal energy has not been utilized to any greater extent. Today geothermal energy is ex-tracted from a two well system at the Margretheholm site and distributed to the district heating system in Copenhagen. Heat is extracted from warm water flowing through absorption heat pumps (225 m3/h and 73°). The producing reservoir (11.8 Dm) is the lower Triassic sandstone interval at 2 550 m depth (mid-point). The geothermal plant has been in full operation since 2006 and generates on a yearly basis approxi-mately 300 TJ heat corresponding to the consumption of 4 000–5 000 households. A similar feasibility pro-ject in the city of Malmö proved a geothermal poten-tial in the Rhaetian, Lower Jurassic and Lower Creta-ceous reservoirs between 1 600–1 820 m depth. A production temperature of 51.5° and 14.0 Dm was verified by tests in two investigation wells. Rejuve-nated interest in developing geothermal resources in Denmark and the Øresund region have stressed the need for comprehensive geological descriptions, mod-els and definition of the structural framework control-ling the distribution and characteristics of the potential geothermal reservoirs. |