## 3 Air Injection Displacement Experiment of Different Pressure
### Production Dynamic Characteristics of Different Pressure Experiments  
By analyzing the key production parameters such as liquid production and gas production, the displacement characteristics and development stability can be clarified.  
Figure 5 shows the production dynamic curve of different pressure experiments. The characteristics of different pressure experiment production stages are basically the same. The initial production is higher, and then the production gradually decreases to a stable level. The oil production in the stable stage is about 2 mL/min. After a period of stable production, the production decreases.  
Table 4 shows the cumulative production dynamic parameters of different pressure experiments. The cumulative gas production-injection ratios of 5 MPa, 15 MPa, and 30 MPa experiments are 0.91, 0.76, and 0.56, respectively. It can be seen from the production gas-oil ratio curve in Figure 6 that the average GOR in the stable production stage of 5 MPa, 15 MPa, and 30 MPa experiments is 675.49 mL/mL, 605.78 mL/mL, and 520.02 mL/mL. Compared with the 5 MPa, 15 MPa, and 30 MPa experimental gas production-injection ratio and GOR, the gas production-injection ratio is small under high-pressure conditions, the gas storage volume is relatively large, the gas production time is late, the GOR is low,  
Figure 5: Production dynamic chart of different pressure experiments.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Numbering**} & **Experimental** & **Air Injection** & **Gas Production, L** & **Gas Storage** & **Air Consumption,** & **Fuel Consumption,** & **Air Consumption** \\  & **Pressure, MPa** & **Volume, L** & **Volume, L** & **Volume, L** & **m\({}^{3}\)/m\({}^{3}\)** & **kg/m\({}^{3}\)** & **(Considering Gas Storage),** \\  & & & & & & & **m\({}^{3}\)/m\({}^{3}\)** \\ \hline
1 & 5 & 302.78 & 277 & 25.78 & 118.46 & 9.93 & 106.69 \\
2 & 15 & 313.58 & 239 & 74.58 & 129.49 & 9.81 & 92.50 \\
3 & 30 & 333.21 & 188 & 145.21 & 144.78 & 9.31 & 76.81 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Oxidation reaction parameters of different pressure experiments considering gas storage.  
the output gas volume is less, the gas channeling does not easily occur, and the stability of the air injection displacement process is enhanced under high pressure.  
As shown in Figure 5, during the displacement process at 5 MPa, a total of 6.7 PV of air was injected, resulting in a final oil displacement efficiency of 90.5%. At 15 MPa, 2.2 PV of air was injected, resulting in a final oil displacement efficiency of 91.80%. Under 30 MPa conditions, only 1.3 PV of air was injected, and the final oil displacement efficiency reached 92.93%. By comparison, under 30 MPa, the injected PV number approached 1, with a displacement rate exceeding 90%, indicating the miscible state during the air injection displacement, resulting in a more stable displacement process.  
In general, with the increase in pressure, the gas production-injection ratio decreases, the gas production time is delayed, the GOR becomes lower, the injected PV number decreases, and the oil displacement efficiency increases.