Microscopic Simulation Experiment for the High-Efficiency Construction of Underground Gas Storage

Abstract Using micro-visualization models and microfluidic technology, simulation experiments were conducted on gas injection for water displacement during the initial stage of storage formation and gas production with water encroachment and gas storage displacement of water bodies during the cyclic storage and extraction phase, in a water-invaded gas reservoir type storage facility. The stability mechanisms of the gas-liquid interface, the laws of gas-liquid seepage and storage were analyzed. This analysis explored optimized control methods for efficient operation through the entire cycle of the gas storage facility. The research shows that during the initial stage of storage construction, the gas injection rate should be regulated to fully utilize gravity, ensuring macroscopic stability and mobility of the gas-liquid interface, significantly enhancing the reach of the gas, and providing more gas storage pore space for subsequent cyclic storage and extraction phases. During the cyclic storage and extraction phase, a constant speed of gas storage and extraction results in low utilization of pore space. Gradually increasing the storage and extraction speed from "small ingestion-small ejection" to "large ingestion-large ejection" can continuously disrupt the balance of forces within the pore throats, expanding the gas storage pore spaces and flow channels, which is beneficial for capacity expansion and efficiency improvement, as well as for peak-shaving and supply stabilization.