# Quantitative Characterization of Micro-Scale Pore-Throat Heterogeneity in Tight Sandstone Reservoir
## 3 Discussions
### Pore Throat Type and Physical Characteristics
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{\begin{tabular}{c} **Pore Size** \\ **Classification** \\ \end{tabular} } & \multirow{2}{*}{**Pore Radius (\(\mu\)m)**} & \multicolumn{2}{c}{**Throat Size**} & \multirow{2}{*}{**Throat Radius (\(\mu\)m)**} \\  & & & & **Classification** & \\ \hline Macro pore & \textgreater{}100 & Coarse throat & \textgreater{}4.0 \\ Meso pore & 100–50 & Medium throat & 4.0–2.5 \\ Small pore & 50–10 & Thin throat & 2.5–1.0 \\ Fine pore & 10–0.5 & Fine throat & 1.0–0.5 \\ Micro pore & \textless{}0.5 & Micro throat & 0.5–0.1 \\ \hline \hline \end{tabular} } \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \end{tabular} \\ \
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} 1} & macro pore-fine throat & 0.7249 & 0.7329 & 0.1640 & 0 & - & - \\
2 & macro pore-micro throat & 0.8224 & 0.7976 & 0 & - & - \\
3 & macro pore-micro throat & 0.7639 & 0.7791 & 0.0611 & - & - \\
4 & macro pore-fine throat & 0.7269 & 0.7630 & 0.2125 & 0.5436 & - & - \\
5 & macro pore-micro throat & 0.7304 & 0.7226 & 0 & - & - & - \\
6 & macro pore-thin throat & 0.7324 & 0.6594 & 0.0165 & - & - & - \\ \hline \hline \end{tabular} \\ \end{tabular} \\ \end{tabular}
\end{table} 
Table 2: Quantitative characterization of pore radius heterogeneity in different pore-throat combination reservoirs. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} **Sample** \\ **Number** \\ \end{tabular} } & \multirow{2}{*}{**Reservoir Types**} & \multirow{2}{*}{
\begin{tabular}{c} **Pore** \\ **Uniformity** \\ \end{tabular} } & \multicolumn{4}{c}{**Uniformity of Different Pore Intervals**} \\ \cline{3-8}  & & & **Maco Pore** & **Meso Pore** & **Small Pore** & **Fine Pore** & **Micro Pore** \\ \cline{3-8}  & & & **>100 \(\mu\)m** & **50–100 \(\mu\)m** & **10–50 \(\mu\)m** & **0.5–10 \(\mu\)m** & **<0.5 \(\mu\)m** \\ \hline
1 & macro pore-fine throat & 0.7249 & 0.7329 & 0.1640 & 0 & - & - \\
2 & macro pore-micro throat & 0.8224 & 0.7976 & 0 & - & - & - \\
3 & macro pore-micro throat & 0.7639 & 0.7791 & 0.0611 & - & - & - \\
4 & macro pore-fine throat & 0.7269 & 0.7630 & 0.2125 & 0.5436 & - & - \\
5 & macro pore-micro throat & 0.7304 & 0.7226 & 0 & - & - & - \\
6 & macro pore-thin throat & 0.7324 & 0.6594 & 0.0165 & - & - & - \\ \hline \hline \end{tabular} \\ \end{tabular}
\end{table} 
Table 3: Quantitative characterization of throat radius heterogeneity in different pore-throat combination reservoir. As can be seen from Table 3, the macro pore-micro throat reservoir only develops micro throat, and the average of total throat uniformity is 0.1356, among which the throat radius of the No.2 and No.3 rock samples are concentrated at 0.2 \(\upmu\)m, and the uniformity of micro-throat and total throat are both 0, indicating an uneven distribution of throat. The micro-throat uniformity and total throat uniformity of the No.5 rock sample is 0.4067, which indicates that their throat distribution is uniform compared with that of the No.2 and No.3 rock samples. The macro pore-fine throat reservoir is mainly composed of fine throat, and a small number of thin throat and micro-throat. The average of the total throat uniformity is 0.7981, among which the total throat uniformity of the No.1 rock sample is better than that of the No.4 rock sample, but the fine-throat uniformity of the No.4 rock sample is better than that of the No.1 rock sample. The macro pore-thin throat reservoir is mainly composed of thin throat, and a small number of fine throat and micro-throat. The total throat uniformity of the No.6 sample is 0.8260.