Figure 2
From: The permeability of fractured rocks in pressurised volcanic and geothermal systems
Rock permeability as a function of effective pressure. The data show the relationship between permeability and effective pressure for 6 of the 7 samples (intact and fractured) with (a) 1.2% porosity, (b) 7.0% porosity, (c) 11.0% porosity, (d) 14.3% porosity, (e) 20.2% porosity, and (f) 30.3% porosity. The impact of fracturing on a system’s permeability is much more pronounced at lower porosities than at higher porosities. Results show that the effect of a fracture on permeability is dampened with an increase in effective pressure (beyond ca. 5–10 MPa), as shown by extrapolation of the best fit (dotted and dashed curves) of the permeability dataset conducted with the pressure vessel (circles). The last sample tested (porosity very close to the sample in (e)) is shown in Supplementary Figure 1.
