The impact of natural fractures on heat extraction from tight Triassic sandstones in the West Netherlands Basin: a case study combining well, seismic and numerical data

Abstract The positive impact that natural fractures can have on geothermal heat production from low-permeability reservoirs has become increasingly recognised and proven by subsurface case studies. In this study, we assess the potential of extraction tight Lower Buntsandstein Subgroup targeted recently drilled NLW-GT-01 well (West Netherlands Basin (WNB)). We integrate: (1) reservoir property characterisation using petrophysical analysis geostatistical inversion, (2) image-log core interpretation, (3) large-scale seismic fault characterisation, (4) Discrete Fracture Network (DFN) modelling permeability upscaling, (5) fluid-flow temperature modelling. First, results inversion indicate Volpriehausen almost no intrinsic porosity or in rock volume surrounding well. Detfurth Hardegsen sandstones show better properties. Second, interpretation shows predominately NW–SE-orientated fractures, which are hydraulically conductive log-normal negative-power-law behaviour for their length aperture, respectively. Third, faults extracted data four different orientations: NW–SE, N–S, NE–SW E–W, with proximity to having a similar strike observed fractures. Fourth, inspection reservoir-scale 2D DFNs, upscaled models fluid-flow/temperature simulations indicates these potentially open significantly enhance effective normally volume. However, our also when closed, values negligible. Furthermore, because active tests were not performed prior abandonment Triassic formations NLW-GT-01, conclusive exist whether connected under conditions. Therefore, based presented findings remaining uncertainties, propose measures test fracture-enhanced conditions should standard procedure projects targeting deep fractured reservoirs.