## 4 Results
Near well S-3, the red and black curves, respectively, are the GR and acoustic velocity logging curves, and the pink scale is the vertical depth (m). Figure 12: Inverted velocity (m/s) section connecting well S-3. NW and SE denote the northwest and southeast directions of the study area, respectively. The two white lines are the top and bottom interfaces of Longmaxi Formation. Near well S-3, the red and black curves, respectively, are the GR and acoustic velocity logging curves, and the pink scale is the vertical depth (m). S-4 is a gas well located near the seismic line C2 (green dashed line in Figure 1b). Figure 13 displays the comparison between seismic fluid mobility section and inverted velocity section connecting well S-4. Figure 13a indicates that the gas zone in well S-4 is located near the bottom interface of the Longmaxi Formation, which is consistent with the actual well data. Figure 13b describes the distribution characteristics of shale reservoirs with low-velocity, where the blue color inside the black ellipse represents a set of low-velocity, thick, and pure shale, i.e., favorable shale reservoir. Comparing Figure 13a,b, we can see that the gas accumulation area predicted from the seismic fluid mobility attribute is located in the favorable shale reservoir interpreted from the inverted velocity data. These results confirm the validity and stability of the seismic fluid mobility attribute technique in identifying the spatial distribution of shale gas enrichment areas. Figure 14 displays the thickness map of the shale gas reservoirs in Longmaxi Formation predicted by seismic fluid mobility attribute technology and seismic inversion technology. The thickness map of shale gas reservoirs is obtained in three steps: first, the time location of shale gas reservoir is estimated using a threshold value of seismic fluid mobility (i.e., \(m>0.3\)), then the thickness data at the twelve seismic lines is calculated by using another threshold value of velocity (i.e., \(3900<v<5300\) m/s), and finally the thickness in the entire study area can be obtained by interpolation technology. As shown in Figure 14, well S-3 has no gas (zero thickness), well S-1 has poor gas content (thickness less than 6 m), and the remaining four wells have good gas content (thickness greater than 10 m), which is matched with the actual drilling result. In addition, the sedimentary facies of the target formation is the transition facies from shallow water shelf in the southeast to deep water shelf in the northwest of the study area. According to the sedimentology theory, with the increase of water depth, the thickness of shale deposition and the maturity of organic matter increase as well as the thickness of shale gas reservoir. Thus, predicted thickness map is consistent with sedimentary background of marine shale. We also give two favorable exploration areas (inside the cyan dotted curves) with large thickness, few  
Figure 13: Seismic fluid mobility section (**a**) and inverted velocity (m/s) section (**b**) connecting gas well S-4. The two white lines are the top and bottom interfaces of Longmaxi Formation. The red curve near well S-4 is GR logging curve, and the pink scale is the vertical depth (m). SW and NE denote the southwest and northeast directions of the study area, respectively. faults, and large burial depth (more than 1000 m), which can be used to guide subsequent exploration of shale gas in the Longmaxi Formation.