盐穴储气库天然气阻溶造腔数值模拟

A numerical simulation for the solution mining under natural gas of salt-cavern gas storage

为指导存在偏溶、形状不规则特点的腔体进行天然气阻溶造腔修复作业,开展了相关数值模拟研究。盐穴修复过程中,为保证腔顶安全,仅对目标深度段进行造腔修复,防止腔顶继续拓展,阻溶剂需求量大,因此选择来源便捷的天然气作为阻溶剂。建立数学模型,考虑盐岩上溶特征,编写盐穴储气库天然气阻溶造腔模拟程序,并针对金坛盐穴储气库L井进行天然气阻溶造腔模拟。天然气阻溶造腔可优化单腔形状和体积,提高优质盐层利用率,降低腔体不规则对注气排卤作业的影响风险,保证腔体满足安全要求。研究结果表明:编制的程序可有效模拟天然气阻溶造腔过程中腔体形状的发展,模拟结果与现场工程作业一致,研究成果对提高单个腔体有效体积及腔体稳定性具有重要意义。

To provide the guidance for the repair of partially dissolved or irregular caverns by means of solution mining under natural gas（SMUNG）, it is necessary to carry out the numerical simulation research. In order to ensure the safety of cavern top in the process of cavern repair, the operation is conducted only at the target depth to prevent the cavern top from extending further. A large amount of blankets is demanded, so natural gas whose source is convenient is taken as the blanket. A mathematical model was established and a simulation program was developed for SMUNG of salt-cavern gas storage. In the simulation, the upper dissolution characteristic of salt rock was taken into consideration. Then, this technology was applied to simulate the SMUNG of Well L in Jintan salt-cavern gas storage. SMUNG can be used to optimize the shape and volume of single-cavern, improve the utilization rate of high-quality salt bed and reduce the effect of cavern irregularity on gas injection de-brining operation, and consequently caverns can meet the safety requirements. It is indicated that the simulation program can effectively simulate the development of cavern shape in the process of SMUNG and its simulation results are consistent with the field operation data. The research results are of great significance to improve the effective volume and cavern stability of single-cavern.