水平腔型盐穴储气库注采运行稳定性分析

Stability Analysis of Horizontal Salt Cavern Gas Storage During Injection and Production Operation

水平腔型盐穴储气库适合我国盐岩地层特点,能充分提高造腔效率与经济效益,其稳定性评价是建设与运行的关键。文章以国内某水平腔储气库真实地层条件为背景,开展水平腔储气库长期注采气循环下的围岩变形规律和注采气影响下的稳定性研究,结果表明:水平腔盐穴储气库注采运行30 a顶板最终变形量为1.72 m,相对于初始腔体高变形量约10%;腔体体积收缩率为19.8%,满足体积收敛准则。围岩有拉伸塑性区产生,但未出现明显连接贯通,夹层不会整体垮落。建立了扩容损伤准则方程,计算围岩未发生扩容损伤破坏。该水平腔储气库满足稳定性要求,为盐穴储气库建设与运行提供有益借鉴。

The horizontal salt cavern gas storage is more suitable for the construction of salt rock formation in China,which can fully improve the cavity building efficiency and economic benefits.The stability evaluation is the key to the construction and operation.In this article,the deformation law of surrounding rock under the long-term gas injection and production cycle and the stability under the influence of gas injection and production are studied based on the real stratum conditions of a horizontal cavity gas storage in China.The results showed that the final deformation of the horizontal salt cavern gas storage roof is 1.72m after 30 years of injection-production operation,which is about 10%of the high deformation of the initial cavern.The volume shrinkage of the cavern is 19.8%,which satisfies the volume convergence criterion.The surrounding rock has tensile plastic zone,but there is no obvious connection,the interlayer will not collapse as a whole.The criterion equation of dilatancy damage is established and no dilatancy damage occurs in surrounding rock.The horizontal gas storage meets the requirement of stability and provides useful reference for the construction and operation of salt cavern gas storage.