Research on Influencing Factors of Natural Gas Leakage Through Boundary Faults in Gas Storage Reservoirs

Gas storage plays an important role in China’s energy supply. The closure of faults is one of the key indicators for the safe operation of gas storage. The formation stress changes caused by high-speed injection and production operations will reduce the closure of faults. Therefore, this paper carries out research from the perspective of dynamic injection and production. On the basis of considering the static tightness of the fault, a mechanism model is established by geological modeling and numerical simulation to simulate the leakage of the boundary fault under different injection-production modes and injection production times. The response mode judges whether there is natural gas loss through the pressure change of the monitoring well on the other side of the fault. The simulation results of the two periods show that the increase of injection production will increase the pressure of the monitoring well. The fault leakage is very significant when the injection production exceeds a threshold. With the increase of injection-production time, the same injection-production amount will reduce the pressure fluctuation of the monitoring wells near the fault. So in the actual operation of the gas storage, it is appropriate to reduce the injection-production volume of the injection-production wells near the fault and extend the injection-production time to better avoid unnecessary losses. On the basis of the previous research on the static mechanics of faults, combined with the actual dynamic operation that may cause natural gas leakage at the fault. This paper builds a mechanism model and applies it to the A gas storage to verify the reliability of the conclusions.