含夹层盐岩椭球储气库极限压力

地下盐岩储气库在调峰和保障供气安全上具有不可替代的作用，确定合理的储气库极限压力具有重要意义。针对盐岩椭球储气库极限压力问题，以某地下盐岩储气库为工程背景，基于Mohr-Coulomb抗剪破坏准则、上限和下限压力判定准则，以大型商业有限元软件ABAQUS为平台，对不同椭球储气库腔体形状尺寸的极限压力问题进行数值模拟研究，探讨盐岩夹层黏聚力和抗拉强度变化对椭球储气库极限压力的影响。结果表明：随着椭球形腔体长短轴之比减小，储气库上限压力随之增大，而下限压力由于采用的本构模型不同，无显著变化规律。当夹层黏聚力和抗拉强度变化时，同储气库极限压力基本不变。在上限压力作用下不同储气库的塑性破坏区域发生在腔体顶部盐岩层；而下限压力作用下，夹层破坏区域基本不变，夹层的存在对椭球储气库极限压力影响不明显。
The underground gas storage in salt rocks plays an irreplaceable role in peak shaving and safety ensuring for gas supply. Therefore, determining the reasonable limit pressure of gas storage is of great significance. With regard to the limit pressure for ellipsoid gas storages, the limit pressures of different ellipsoid sizes of gas storages are calculated by using the finite element software ABAQUS. The limit pressures are discussed by the Mohr-Coulomb shear failure criterion, maximum pressure criterion and minimum pressure criterion. Besides, effects of the varying cohesion and tension strength of interlayer of underground salt rock gas storages on the limit pressure are studied. The results show that the limit pressure of the gas storage increases with the decrease of the ratio of the axis length of ellipsoid cavity. While the limit pressure of the same gas storage does not change with the variation of cohesion and tension strength. When different gas storages attain the maximum pressure, damage occurs at the top of the salt rock cavity, and for the minimum pressure, the damage area of the interlayer is basically unchanged. The existence of interlayer has little influence on the limit pressure of ellipsoid gas storages