## 3 Experimental Rock Characterization Methods
### X-CT Imaging  
X-CT scanning was performed using a Nikon XT H 320/225 system (Nikon Corporation, Tokyo, Japan), equipped with a 225 kV reflection gun and a 2000 - 2000 pixel flat panel photodetector (cell size 0.2 mm - 0.2 mm). The scanning conditions used are summarized in Table 3. Initially, an accelerating voltage of 150 kV was used for each sample with 40 uA current, apart from piece A of sample F4 where a 53 uA current was used. For the first round of scans, the X-ray source to sample distance was set to achieve a minimal voxel size of ~7 um, as shown in Table 3. A final scan was conducted on a small sub-volume of sample F3 at a higher resolution, after adjusting the accelerating voltage and current (Table 3). No filters were used for these scans. The exposure time for each projection was 1.41 s, repeated for 3141 projections, the total duration for each analysis thus being roughly an hour and a quarter. Figure 4 summarizes the workflow for this imaging and the subsequent image processing. \begin{table}
\begin{tabular}{l c c c c c} \hline
**Production** & **Depth** & **Depth** & **Thickness** & **Q\({}_{\mathbf{i}}\)** & **F\({}_{\mathbf{i}}\)** & **K\({}_{\mathbf{i}}\)** \\ \hline
**Interval, i** & **Top [m]** & **Base [m]** & **H\({}_{\mathbf{i}}\) [m]** & **[L/min]** & **[\%]** & **[mD]** \\ \hline _Well VS-1_ & & & & & & \\
1 & 1643.9 & 1646.5 & 2.6 & 20 & 4.4 & 65 \\
3 & 1665.8 & 1669.7 & 3.9 & 20 & 4.4 & 44 \\
4 & 1745.0 & 1755.0 & 10.0 & 110 & 23.9 & 92 \\
5 & 1793.0 & 1794.7 & 1.7 & 30 & 6.5 & 147 \\
6 & 1810.7 & 1817.9 & 7.2 & 15 & 3.3 & 18 \\
7 & 1856.0 & 1857.3 & 1.3 & 20 & 4.3 & 128 \\
9 & 1882.0 & 1886.5 & 4.5 & 25 & 5.4 & 46 \\
10 & 1891.0 & 1893.7 & 2.7 & 70 & 15.2 & 217 \\
11 & 1898.0 & 1899.8 & 1.8 & 10 & 2.2 & 47 \\
12 & 1920.0 & 1927.6 & 7.6 & 140 & 30.4 & 154 \\ Total & & & 43.3 & 460 & & \\ _Well T-1_ & & & & & & \\
1 & 1828.5 & 1833 & 4.5 & 130 & 37 & 201 \\
2 & 1907.5 & 1910.5 & 3.0 & 120 & 34 & 278 \\
3 & 1942.5 & 1947.5 & 5.0 & 100 & 29 & 142 \\ Total: & & & 12.5 & 350 & & \\ \hline \end{tabular} This analysis is based on Equations (1) and (2). K\({}_{\mathbf{i}}\) is the estimated permeability of the ith production interval.  
\end{table} 
Table 1: Production logging of wells VS-1 and T-1. \begin{table}
\begin{tabular}{l c c c} \hline
**Sample** & **F1** & **F3** & **F4** \\
**Facies** & **Silstone** & **Med. Grained St** & **Fine Grained St.** \\ \hline Analysis & & & & Property \\ \hline X-CT imaging & Y & Y & Y & Porosity \\ X-ray Diffraction (XRD) & Y & Y & & Mineralogy \\ Thin section & Y & Y & Y & Mineralogy \\ Scanning Electron Microscope (SEM) & Y & Y & Y & Mineralogy \\ Mercury Intrusion Porosimetry (MIP) & Y & Y & Y & Porosity, density \\ Numerical flow simulation & Y & & Permeability \\ \hline \end{tabular}
\end{table} 
Table 2: Summary of experimental analyses. Figure 4: Summary of the workflow for X-CT imaging, followed by image processing and numerical flow simulation. Modified after Figure 1 of [31]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sample** & **Notes** & **Scan** & **Voxel Size (\(\mu\)m)** & **Scan Size (Voxels)** & **Voltage (kV)** & **Current (\(\mu\)A)** \\ \hline F1 & & H1 & 7.47888 & 1684 & 1436 & 1592 & 150 & 40 \\ F4 & (1) & H2 & 8.78948 & 1494 & 1556 & 1779 & 150 & 53 \\ F3 & & H3 & 7.14653 & 1590 & 1751 & 1866 & 150 & 40 \\ F4 & (2) & H4 & 6.52282 & 1609 & 1370 & 1936 & 150 & 40 \\ F3 & (3) & H3-HR & 2.78965 & 2000 & 2000 & 1399 & 140 & 19 \\ \hline \hline \end{tabular}  
Notes: (1) piece ‘A’ of sample F4; (2) piece ‘B’ of sample F4; (3) ‘High resolution’ (HR) analysis of a sub-volume of sample F3.  
\end{table} 
Table 3: X-CT scan conditions. To ensure accurate quantitative results, high quality images that avoid sources of error, such as artefacts due to the reconstruction process, are necessary.