Research and Application of Water Pressure Method and Air Pressure Test Method for Underground Gas Storage Caverns of Hundred-Megawatt Compressed Air Energy Storage

Underground gas storage reservoirs are core pressure-bearing facilities of compressed air energy storage power stations. Pressure tests can verify the strength and sealing performance of steel-lined cavities, wellbores and pipe manifolds, with hydrostatic pressure testing and air pressure testing serving as the two mainstream testing processes. Based on the 100MW/400MWh artificial steel tank gas storage reservoir project for compressed air energy storage in Zhangbei, this paper systematically compares the principles, procedures, safety risks and applicable boundaries of the two pressure testing processes. Combined with the alpine climate in Zhangbei, supporting conditions of five-stage compressors, pre-inspections of steel lining tapping and surrounding rock void separation, a calibration formula for the 10 MPa test pressure is derived to quantify the varying impacts of climate on the two testing methods. It analyzes the selection logic of gas storage reservoirs such as salt caverns and artificial steel tanks, and sorts out full-process risk control schemes for air pressure testing. The study shows that the hydrostatic method features high safety and intuitive leakage detection, yet it is restricted by frost heave under low winter temperatures. Air pressure testing enables year-round construction on the Bashang Plateau; relying on five-stage compressors, it can stably conduct high-pressure testing at 10 MPa, making it the optimal solution for this project. Relevant conclusions can provide technical support for pressure testing construction of similar compressed air energy storage gas storage reservoirs.