@article{Henningsen_Høimann Jensen_Hemmingsen Schovsbo_Thorshøj Nielsen_Krarup Pedersen_2018, place={Copenhagen, Denmark}, title={Shale fabric and organic nanoporosity in lower Palaeozoic shales, Bornholm, Denmark}, volume={41}, url={https://geusbulletin.org/index.php/geusb/article/view/4332}, DOI={10.34194/geusb.v41.4332}, abstractNote={<p>In organic-rich shales, pores form during oil and gas genesis within organic matter (OM) domains. The porosity thus differs markedly from that of conventional reservoir lithologies. Here we present the first description of shale fabric and pore types in the lower Palaeozoic shales on Bornholm, Denmark. The pores have been studied using the focused ion beam scanning electron microscope (FIB-SEM) technique, which allows for high resolution SEM images of ion polished surfaces. Shale porosity is influenced by many factors including depositional fabric, mineralogical composition, diagenesis and oil and gas generation (Schieber 2013). Here we discuss some of these factors based on a study of lower Palaeozoic shale samples from the Billegrav-2 borehole on Bornholm (Fig. 1) undertaken by Henningsen & Jensen (2017). The shales are dry gas-mature (2.3% graptolite reflectance; Petersen <em>et al</em>. 2013) and have been extensively used as analogies for the deeply buried Palaeozoic shales elsewhere in Denmark (Schovsbo <em>et al</em>. 2011; Gautier <em>et al</em>. 2014). The Danish lower Palaeozoic shale gas play was tested by the Vendsyssel-1 well drilled in northern Jylland in 2015. Gas was discovered within a <em>c</em>. 70 m thick gas-mature, organic rich succession (Ferrand <em>et al</em>. 2016). However, the licence was subsequently relinquished, due to a too low gas content. The present study confirms a close similarity of pore development between the shales on Bornholm and in the Vendsys sel-1 indicating a high porosity within this stratigraphic level throughout the subsurface of Denmark. However, the rather different development of porosity in the different shale units presents a hitherto neglected aspect of the Palaeozoic gas play in Denmark.</p>}, journal={GEUS Bulletin}, author={Henningsen, Lucy Malou and Høimann Jensen, Christian and Hemmingsen Schovsbo, Niels and Thorshøj Nielsen, Arne and Krarup Pedersen, Gunver}, year={2018}, month={Aug.}, pages={17–20} }