Abstract. Cementation of potential reservoir rocks is a geologicalrisk, which may strongly reduce the productivity and injectivity of areservoir, and hence prevent utilisation of the geologic subsurface, as itwas the case for the geothermal well of Allerm?he, Germany. Severalfield, laboratory and numerical studies examined the observed anhydritecementation to understand the underlying processes and permeabilityevolution of the sandstone. In the present study, a digital rock physicsapproach is used to calculate the permeability variation of a highlyresolved three-dimensional model of a Bentheim sandstone.Porosity-permeability relations are determined for reaction- andtransport-controlled precipitation regimes, whereby the experimentallyobserved strong decrease in permeability can be approximated by thetransport-limited precipitation assuming mineral growth in regions of highflow velocities. It is characterised by a predominant clogging of porethroats, resulting in a drastic reduction in connectivity of the porenetwork and can be quantified by a power law with an exponent above ten.Since the location of precipitation within the pore space is crucial for thehydraulic rock properties at the macro scale, the determinedporosity-permeability relations should be accounted for in large-scalenumerical simulation models to improve their predictive capabilities.
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