## 2 Materials and Methods
### Pore Network Modeling  
To increase the number of samples, we extracted sub-volumes from each sample before (Figure 2a) and after (Figure 2b) their dissolution, as illustrated in Figure 2. The extraction of sub-volumes was performed using Avizo(r) Software 2019.1 [33]. The physical volume of each sub-volume equals \(\sim\)8\({}^{3}\) mm\({}^{3}\), and this exceeds the representative elementary volume (REV) for each sample (Figure 3). Most importantly, the identity of each sub-volume and location of extraction from 3D digital sample models was ensured, corresponding to its state before and after the injection of HCl solutions, so that it was possible to compare the characteristics of sub-volumes before and after rock dissolution. The ejected sub-volumes were either impermeable or coincident/intersected with wormholes. Thus, 408 sub-volumes were completely extracted from all considered samples (see Table 3).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{Sample Name} & **Mass Concentration of** & **Flow Rate, mL/min** & \
\begin{tabular}{c} **Permeability after HCl** \\ **Injection, \(\mu\)m\({}^{2}\)** \\ \end{tabular} & **Permeability Ratio** &
\begin{tabular}{c} **Breakthrough Pore** \\ **Volumes, PV** \\ \end{tabular} \\ \hline \#1 & 18 & 2 & 0.98 & 3.38 & 2.9 \\ \hline \#2 & 18 & 8 & 3.79 & 8.81 & 2.4 \\ \hline \#3 & 12 & 8 & 3.85 & 5.42 & 4.2 \\ \hline \#4 & 12 & 4 & 4.10 & 9.11 & 4.4 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Flow conditions of HCl through the samples and permeability of samples after injection.  
Figure 1: Schematic of the experimental setup.  
Once the sub-volumes from all cylindrical samples were extracted, pore network modeling (PNM) was carried out using Avizo(r)[33]. Avizo(r) is a powerful software that allows users to process X-ray microcomputed tomography images and build 3D digital models of samples, as well as to perform PNM of the fluid flow to determine the microscopic and macroscopic properties of samples [34; 35]. As a consequence of PNM, the total and connected porosity, specific surface area, radius of all and only connected pores, hydraulic tortuosity, and absolute permeability were computed. Avizo(r) automatically computes the absolute permeability using [PERSON]'s law, the applicability of which was confirmed by calculations on several randomly chosen sub-volumes (Figure 4). All computations were conducted on the following boundary conditions: the inlet pressure was 1.3 atm and the outlet pressure was 1.0 atm, and at the other boundaries of the sub-volume, the no-flow  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Name of the Cylindrical Sample** & **\#1** & **\#2** & **\#3** & **\#4** \\ \hline \multirow{2}{*}{Number of sub-volumes extracted} & Before injection & 59 & 56 & 52 & 37 \\ \cline{2-5}  & After injection & 59 & 56 & 52 & 37 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Number of sub-volumes extracted from cylindrical samples.  
Figure 2: Schematic illustration of the extraction process of sub-volumes from a cylindrical sample: (a) before injection; (b) after injection; (c) enlarged sub-volume.  
condition was set. Water was used as the working fluid, the viscosity of which is 1 mPa-s at room temperature.