Extended evaluation of possible geothermal reservoirs in the Helsingør area including geological data from Helsinborg and Øresund. Contribution to an evaluation of the geothermal potential

This report is prepared by GEUSand SGU for Forsyning Helsingør with the objective toimprove the understanding of the geothermal potential of sandstone formations in the Helsingør area.

An initial assessment of the geothermal potential in the Helsingør area was presented in a report (Hjuler et al. 2013) based on relevant well and seismic data.From this report it becomes clear that the unavailability of quality data in the study area in combination with complicated regional geology impedes a well substantiated characterization of quality and continuity of thepotential sandstone reservoirs. The report, however, also showed that several formations including the Lower Cretaceous Unit, the Lower Jurassic Unit, the Gassum Formation and the Bunter Sandstone Formation possess geothermal potential.

The geothermal potential of these formations were further examined and verified in a petrographical analysis of selected cuttings samples from the Karlebo-1/1A well (Nielsen et al. 2014).

A new study based on the vast amount of geodata from the Helsingborg area was proposed in order to further strengthen the reservoir quality assessments presented inHjuler et al. (2013) and Nielsen et al. (2014). The objective was to obtain more information of the spatial distribution and quality of potential reservoirs in the Helsingør area by evaluating and analysing the significant amounts of geological data available from the Helsingborg area. In the first phase of this study an overview of the vast amount of samples and datawas established. The results of thesecond phase include analyses of biostratigraphy, cores (porosity-permeability), petrophysics, petrography and shallow seismic data in order to facilitate comparison and correlation of Danish wells to a constructed composite succession in the Helsingborg area. In the lastthird phase of the study the geothermal potentialin the Helsingør area is re-assessed by integrationof the Helsingborg data and data from the tunnel line between Helsingør and Helsingborg(Larsen et al. 1968) with the previous assessment (Hjuler et al. 2013). In addition, a parallel study on the relation between porosity and permeability has been performed for Sjælland, and the results of this study have also been utilised and integrated with the Helsingborg study.