For instance, B8 and B9 do not have any link to the in situ stress state. The latter is using only elastic rock parameters to make statements about failure processes, which may yield erroneous results. Not only will the brittleness increase with increasing stress (as demonstrated in Fig. 12). Furthermore, Young’s modulus correlates to high strength and to low porosity (e.g. Plumb, 1994 and Horsrud, 2001), which are detrimental to facilitating fracture initiation and typical of low porosity rocks (i.e.