Performance Evaluation of Multi-Cycle Injection-Production of Sizhan Gas Storage

The dynamic analysis of multi-period injection and production of gas storage is of great significance for deepening the understanding of the variation law of gas well injection and production capacity, implementing the peak regulating capacity of each cycle, verifying the capacity and production degree of gas storage, water invasion and gas-water interface changes. Taking Sizhan gas storage as an example, a fine numerical model was established to simulate the process of alternating injection and production, and the variation law of pressure connectivity and water invasion was clarified. By establishing binomial productivity equation during gas injection and production period of a single well, the variation interval of gas injection and production capacity was determined. The material balance method was used to calculate the inventory of different periods, effective inventory, peak regulating capacity, capacity and production degree. The results show that the overall connectivity of Sizhan gas storage is good, but the central and southern regions are disconnected due to the restriction of river division. The dynamic water body size is about 173.65 × 104 m3and the dynamic water body multiple is 0.4 times. The water invasion amount after multi-period injection is 1.02 × 104 m3 At the end of multi-period injection, the gas-water interface decreases by 2 m, and water invasion has little influence on the gas storage. The gas injection and recovery capacity of the gas storage ranges from 338.2–53.9 × 104 m3/d, and the gas recovery capacity ranges from 352–13.2 × 104 m3d, which has a high coincidence rate with the design. The multi-period injection and production rate of the gas storage is 75% and 50%. The multi-period injection and production dynamic evaluation method provides a reliable basis for the optimization of the operating parameters of Sizhan gas storage, and has certain reference significance for other gas storage.