多夹层盐穴储气库群间矿柱稳定性研究

以某拟建多夹层盐穴储气库为工程背景，利用FLAC^3D建立了拟建盐穴储气库有限元计算模型，讨论了矿柱宽度、内压、埋深、蠕变时间和相邻盐穴内压差等参数对盐穴储气库间矿柱受力和变形影响规律，分析了在注采气时间同步和不同步工况下矿柱的稳定性。计算结果表明：矿柱中的应力随着埋深和相邻盐穴压差的增加而增加，随着矿柱宽度、内压和蠕变时间的增加而降低，但内压影响不显著；蠕变使得矿柱中应力逐渐变均匀，5 a以后影响不显著；内压差在蠕变过程中使得矿柱的蠕变位移大幅增加；注采气时间不同步模式对矿柱稳定不利，尤其当矿柱宽度较小时更为显著。建议盐穴储气库间矿柱宽度取2~3倍盐穴直径，相邻盐穴间矿柱宽度较小时，尽量不采用注采气时间不同步模式运行。

Stability analysis of pillars between bedded salt cavern gas storages

The numerical simulation models of bedded salt cavern gas storages were built by the FLAC 3D.The influences of pillar width,gas pressure,cavern depth,creep time and pressure difference of adjacent salt caverns on the stresses and deformations of pillars between salt cavern gas storages were studied.The effects of synchrony and asynchrony injection production modes on the pillars stability were discussed.The comprehensive results show the stresses of pillars increase with cavern depth and pressure difference,whereas decrease as the increase of pillar width,gas pressure and creep time.The gas pressure has little effects on the stresses of pillars.The creep time makes the stress of pillar gradually change to uniformity,and 5 years later the effect is not significant.The pressure difference has great influence on the creep deformations of pillars.The asynchrony injection production mode has negative effects on the stability of pillars,especially the pillar with narrow width.The suggested widths of pillars are 2~3 times of salt cavern diameter,and the asynchrony injection production mode should be avoided during actual adjacent salt cavern gas storages with narrow pillar width running.