## 3 Boundary of Low-Resistivity Shale Reservoir  
At present, the boundaries for low-resistivity shale reservoirs are mainly divided into two categories. One is the absolute value of resistivity logging, which refers to shale reservoirs with resistivity less than 10 \(\Omega\cdot\)m; another type is the rate of increase in resistivity, which is less than two to determine the low-resistivity shale reservoir. Different scholars define different values of low resistance intervals in different research areas, and overall, the classification of shale low-resistance thresholds is unclear, with an insufficient basis for classification [3; 12; 13]. Based on the relationship between resistivity and thickness, shale gas wells in Luzhou area can be divided into two categories in this study. A type represented by Well L206 (including Well L206, L208, L210, Y101H10-3, and Y101H3-8), the thickness of the formation with resistivity less than 10 \(\Omega\cdot\)m in 1-3 sub layers is 3.71 m,accounting for 33.3% of the total formation thickness (Figure 2a), and the thickness of shale with resistivity less than 10 \(\Omega\cdot\)m in 4 sub layers is 27.44 m, accounting for 44.4% (Figure 2b). Another type, represented by Well L211 (including Well Y101H88-1, Y101H91-4, and JYT1), has a formation thickness of 20.75 m with a resistivity less than 10 \(\Omega\cdot\)m in 1-3 sub layers, accounting for 100% of the total formation thickness (Figure 2a), and 51.13 m with a resistivity less than 10 \(\Omega\cdot\)m in 4 sub layers, accounting for 78.9% (Figure 2b). The resistivity of shale gas wells in the former is only partially less than 10 \(\Omega\cdot\)m, exhibiting an intermittent distribution; the majority of the latter formations have a resistivity less than 10 \(\Omega\cdot\)m and exhibit a continuous distribution. Therefore, this study utilizes previous research results and combines the thickness of the formation resistivity interval with parameters related to shale gas production to determine the low-resistance limit of shale reservoirs.  
This study statistically analyzed the daily production of each well for the first three months before production in the Luzhou area and its adjacent areas, as well as the average gas content of the 1-3 sub layers. It was found that the daily average gas production of the gas producing wells was greater than 6 \(\times\) 10\({}^{4}\) m\({}^{3}\), and the corresponding target production layer had an average gas content greater than 4 m\({}^{3}\)/t (Figure 3a). Through the relationship between daily average gas production, target layer average gas content, and average resistivity of 1-3 sub layers, it is shown that when the resistivity is below 10 \(\Omega\cdot\)m, the daily average gas production is less than 0.2 \(\times\) 10\({}^{4}\) m\({}^{3}\), and the average gas content of 1-3 sub layers is less than 4 m\({}^{3}\)/t (Figure 3b,c). Therefore, when the resistivity of shale gas wells is below 10 \(\Omega\cdot\)m, the production capacity of shale gas wells is also related to the thickness of the reservoir [3].  
Figure 2: Distribution relationship between resistivity and formation thickness of shale in Well L205 and L211. (**a**) Distribution of resistivity and thickness relationship in 1-3 sub layers of Well L205. (**b**) Distribution of resistivity and thickness relationship in 4 sub layers of Well L205. (**c**) Distribution of resistivity and thickness relationship in 1-3 sub layers of Well L211. (**d**) Distribution of resistivity and thickness relationship in 4 sub layers of Well L211.  
According to a statistical analysis of the data, when the main production layer has low resistance (resistivity below 10 \(\Omega\)\(\cdot\)m) and the formation thickness is greater than 6 m, the shale gas well production is extremely low and does not have industrial development value (Figure 3d). Based on this, it is believed that reservoirs with a resistivity less than 10 \(\Omega\)\(\cdot\)m and a formation thickness greater than 6 m are low-resistance shale reservoirs.