8
is zero. The approach for calculating the permeabilities in
the model is based on the Cubic Law and Darcy’s equation.
As part of the calibration efforts, the mechanical apertures
are reduced by 60% to represent the hydraulic apertures
(Khademian et al., 2021).
The objective here is to calculate permeability val-
ues and compare them with the field measurements. The
contribution of bedding planes or vertical fractures to the
overall of the permeability measured by slug tests can-
not quantitatively be determined. Besides, it is not clear
what volume of rock surrounding the perforated intervals
is represented by the measured permeability of slug tests.
However, if the permeability of the borehole wall at the
perforation intervals is less than that farther away from the
borehole, the lower permeability values determine the flow
conditions. Thus, we calculate permeabilities in each layer
within a 44-m abutment pillar width and then 22 m radii
from the borehole locations and select the minimum values
between the two. Based on fracture densities, one may fur-
ther reduce the length to find the minimum permeability
Figure 10. 3DEC results on the aperture values in mm for bedding planes (a) after mining the first panel (b) after mining the
second panel (c) after mining the third panel
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