Scaling of transport coefficients of porous media under compaction
Department of Mathematics, University of Leicester - Leicester LE1 7RH, UK, EU and Institute of Continuous Media Mechanics, UB RAS - Perm 614013, Russia
Accepted: 3 August 2011
Porous sediments in geological systems are exposed to stress by the above-lying mass and consequent compaction, which may be significantly nonuniform across the massif. We derive scaling laws for the compaction of sediments of similar geological origin. With these laws, we evaluate the dependence of the transport properties of a fluid-saturated porous medium (permeability, effective molecular diffusivity, hydrodynamic dispersion, electrical and thermal conductivities) on its porosity. In particular, we demonstrate that the assumption of a uniform geothermal gradient is not adequate for systems with nonuniform compaction and show the importance of the derived scaling laws for mathematical modelling of methane hydrate deposits; these deposits are believed to have potential for impact on global climate change and glacial-interglacial cycles.
PACS: 47.56.+r – Flows through porous media / 92.40.Kf – Groundwater / 91.50.Hc – Gas and hydrate systems
© EPLA, 2011