## 3 Analysis of Experimental Results
### Water Invasion Simulation Experiment for Multi-Well Development of Fracture Model
According to the real-time gas and water production measured in the experiment, the change in the production water-gas ratio during the experiment could also be obtained. The experimental water-gas ratio was defined as the ratio of water production (mL) to gas production (10\({}^{4}\)  
increase in the recovery rate. The low-position gas well continued to produce water after the water breakthrough, which could delay the water breakthrough time of the high-position gas well and reduce the water-gas ratio of the high-position gas well. The water-gas ratio of simulation well 3 increased gradually after the water breakthrough, and the maximum water-gas ratio could reach 28.5. The maximum water-gas ratios of simulation well 2 and simulation well 1 were 14.3 and 3.7, respectively. Under the seven times water body condition, the water breakthrough times of simulation well 3, simulation well 2, and simulation well 1 were advanced to 11.8%, 30.5%, and 35.8%, respectively (Figure 8b). The maximum water-gas ratio of simulation well 3 was increased to about 36.5, and the maximum water-gas ratios of simulation well 2 and simulation well 1 were increased to about 17.8 and 5.7. Compared with the condition of not shutting in after water breakthrough, under the condition of seven times water body (shut-in after water breakthrough), the overall water production of the gas reservoir decreased, the water-free production period increased, and the recovery rate of the gas reservoir decreased significantly (Figure 8c). As shown in Figure 9, in the early stage of water invasion, the fracture provided a seepage channel for water invasion. The water invasion front advanced rapidly along the fracture, and the water saturation in the fracture area increased rapidly. In contrast, the water saturation in the matrix area remained almost unchanged. However, analyzing the water saturation change in the matrix area within the fracture range revealed that the reservoir matrix experienced imbibition under the effect of capillary force, leading to an increase in water saturation. Regarding simulation well 3 after the water breakthrough, the water saturation in the fracture area increased dramatically. In contrast, the water saturation in the matrix area also increased but at a significantly slower rate than in the fracture region (Figure 10). When the experiment ended, the water saturation of three times water body was about 78% (Figure 11), and the water saturation of seven times water body was about 85% (Figure 12). At the same time, further analysis shows that there was local water-trapped gas around the fracture area and the edge of the gas reservoir. Figure 8: Relationship between production water–gas ratio and recovery rate of fracture model. (**a**) Three times water body; (**b**) seven times water body; (**c**) seven times water body (shut-in after water breakthrough). Figure 11: Variation in water saturation in different areas of the fracture model at the end of the experiment (3 times water body). Figure 10: Variation in water saturation in different areas of the fracture model at the water breakthrough time of simulation well 3 (3 times water body). Figure 9: Variation in water saturation in different areas of the fracture model during early water invasion (3 times water body). Water Invasion Simulation Experiment for Multi-Well Development of Fracture-High-Permeability Zone Model  
As shown in Figure 13a, under the three times water body condition, the bottom hole pressure changes in an up-concave shape with the increase in recovery rate, consistent with the fracture model with the water body. However, the recovery rate corresponding to the inflection point, the ultimate recovery rate (41.8%), and the overall waterflood efficiency (34.5%) were lower than the fracture model with the same water body multiple.