Figure 6: PCA of the glass bead sample. (A) PCA image; (B) Histogram of
pore size distribution; and (C) photograph of the glass beads in a 15 mL
falcon tube, where the blue line indicates the FOV.
MRI image sets of Berea sandstone, Indiana Limestone, and Madison
Limestone, with pore spaces tighter than other cores previously reported
in the literature [1,3,14], were collected using the ZTE pulse
sequence. These images were processed and analyzed using the Mathematica
notebook described previously. Figure 7 compares the three different
core samples in their 3D reconstructions with filters applied. The
yellow hue indicates the presence of water in the pore spaces. It is
clear from Figure 7 that all three samples are saturated with water, as
seen by the bright yellow hue throughout the cores. The Berea sandstone
appears more homogeneous with even dispersal of both yellow (water) and
red (solid material or space devoid of water) (Figure 7A and 7D). The
Indiana Limestone core shows that higher water saturation occurs on the
top and bottom of the core (Figure 7B and 7E). The Madison Limestone has
larger and more disconnected pore spaces, exemplified by the more
concentrated yellow hue wrapping through the core in Figure 7C and 7F.