## 3 Rock 3D Structure Creation
### Simulation Study of One-Way Entrance without Wall Seepage
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Entrance Surface**} & \multirow{2}{*}{**Pemeability (10- 3 \(\mu\)m\({}^{2}\))**} & \multirow{2}{*}{**Exit Surface**} & \multirow{2}{*}{**Permeability (10- 3 \(\mu\)m\({}^{2}\))**} & \multirow{2}{*}{**Percentage (\%)**} \\ \hline \multirow{4}{*}{X} & \multirow{4}{*}{191} & –X & 50.8 & 10.65 \\  & & Y & 50.2 & 10.53 \\  & & –Y & 138.4 & 29.02 \\  & & Z & 120.9 & 25.35 \\  & & –Z & 116.5 & 24.43 \\ \hline \multirow{4}{*}{–X} & \multirow{4}{*}{188} & X & 53.7 & 11.43 \\  & & Y & 218.4 & 46.47 \\  & & –Y & 43.2 & 9.18 \\  & & Z & 41.2 & 8.77 \\  & & –Z & 113.3 & 24.11 \\ \hline \multirow{4}{*}{Y} & \multirow{4}{*}{199} & X & 50.8 & 10.21 \\  & & –X & 201.8 & 40.60 \\  & & –Y & 85.5 & 17.21 \\  & & Z & 68.8 & 13.84 \\  & & –Z & 89.9 & 18.10 \\ \hline \multirow{4}{*}{–Y} & \multirow{4}{*}{186} & X & 119.6 & 25.69 \\  & & –X & 73.2 & 15.72 \\  & & –X & 87.1 & 18.70 \\  & & Z & 107.1 & 23.00 \\  & & –Z & 78.6 & 16.88 \\ \hline \multirow{4}{*}{Z} & \multirow{4}{*}{149} & X & 99.1 & 26.63 \\  & & –X & 35.6 & 9.56 \\  & & ✓ & 78.3 & 21.04 \\  & & –Y & 110.2 & 29.62 \\  & & –Z & 48.9 & 13.15 \\ \hline \multirow{4}{*}{–Z} & \multirow{4}{*}{217} & X & 112.3 & 20.72 \\  & & –X & 128.1 & 23.64 \\  & & ✓ & 149.3 & 27.56 \\  & & –Y & 89.8 & 16.57 \\  & & Z & 62.3 & 11.49 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Permeability distribution of each exit surface under different seepage entrance surface conditions. Figure 19: Pressure distribution of X-directional seepage water under a 5 MPa pressure drop. Figure 20: Pressure nephogram of different cross sections of x-multi-directional seepage under a 5 MPa pressure drop. Figure 21: Cloud diagram of different cross-section velocities of X multidirectional seepage under a 5 MPa pressure drop. Table 10 shows that due to the differences in the development of the pore structure in various directions, the fluid flow direction tended to the exit surface with a larger pore channel radius and a shorter seepage path. By calculating the percentage, it can be found that there was always an optimal seepage exit surface among all exit surfaces corresponding to each seepage entrance surface. The permeability data in Table 10 have a large change, which may be due to the change of the calculated value due to the change of the size of the seepage channel in the complex seepage process. The data changes in Table 10 are generally about two to three times (except for very few data), which is similar to the data in Table 1 (about three times changes). In addition, if the cell size in this study is 500 \(\upmu\)m or other sizes, the permeability data may change accordingly, which will be further studied in the future. A total of 29.02% of the fluid entering from the +X surface exited from the exit of the \(-\)Y surface. The order of the proportions of the fluid on each exit surface was ranked as \(-\)Y \(>+\)Z \(>-\)Z \(>-\)X \(>+\)Y. This shows that the \(-\)Y exit surface was the best percolation exit surface of the +X entrance. A total of 46.47% of the fluid entering from the \(-\)X surface flowed out from the +Y surface exit, and the proportion of the fluid at each exit surface was in the order of Y \(>-\)Z \(>\)X \(>-\)Y \(<\)Z. This shows that the +Y exit surface was the best percolation exit surface of the \(-\)X entrance. A total of 40.60% of the fluid entering from the +Y surface flowed out from the exit of the \(-\)X surface, and the proportions of the fluid at each exit surface were in the order of \(-\)X \(>-\)Z \(>-\)Y \(>+\)Z \(>\)X, which indicates that the \(-\)X exit surface was +, which was the best percolation exit surface for the Y entrance. A total of 25.69% of the fluid entering from the \(-\)Y surface flowed out from the +X exit surface, and the proportions of the fluid on each exit surface were sorted as +X \(>+\)Z \(>\)