Reservoir characteristics and diagenesis of the Buntsandstein sandstones in the Campine Basin (NE Belgium)

The red beds of the Buntsandstein (Early Triassic) in Campine Basin (NE Belgium) display porosities between 5.3–20.2% (average 13.7%) and permeabilities varying 0.02–296.4 mD 38.7 mD). Knowledge their reservoir controlling properties, which today are missing, is important view potential geological storage CO2 or natural gas geothermal within these sandstones. Therefore effects diagenesis were assessed based on petrography, stable isotope analyses, fluid inclusion microthermometry, X-ray diffraction, electron microprobe porosity-permeability core analyses. These sandstones deposited by a dryland river system, warm, mostly arid climate with episodic rainfall high evaporation rates. During wetter periods especially feldspars dissolved. Strong during dry led to reprecipitation dissolved species as K-feldspar quartz overgrowths, smectite calcite/dolomite. Sediment reworking resulted framework grains becoming clay coated. coats better developed finer than coarser grained sediments. original composing rims converted illite burial. tangential orientation platelets illite-mica-induced dissolution burial/compaction, manifested bedding parallel seams that filled clays micas, fine-grained sandstone/siltstone/claystone. constitute barriers vertical flow reservoir. released silica did not really affect but was exported (often mm cm scale) nearby bleached horizons, where nucleation inhibiting less well developed. colour arises from presence small amounts Fe-oxides inherited rims. Migration fluids enriched organic acids, expelled underlying Carboniferous coal-bearing strata, local bleaching horizons. In sediments, preserved, suggests reductive capacity limited.