Fig. 15

Evolution of the hydraulic, geomechanical, and poroelastic properties of the Malm aquifer rock as a result of diagenetic processes. The porosity and geometry of the pores and pore throats are altered and rearranged in the different stages of diagenesis. From early to late burial diagenesis the porosity of the investigated samples mainly decreases. The distribution of pore throat diameters (blue lines) and the connectivity of the pore network (red lines) vary throughout the different stages and control the permeability of the rock. Rock strength increases with increasing dolomitization and decreasing porosity, while the stress sensitivity of porosity is decreasing simultaneously. The stress sensitivity of permeability depends on the connectivity of the pore network and the occurrence of micro-fractures and does not show a clear trend. See text for more details. Sketches are modified after Wang et al. (2015). \({k}^{i}\)—initial permeability, \({\varPhi }^{i}\)—initial effective porosity, \({K}_{d}\)—drained bulk modulus, \({\sigma }_{d}\)—rock strength, \(b\)—stress sensitivity coefficient of permeability, \(c\)—stress sensitivity coefficient of porosity