盐岩水平储气库的相似模拟建腔和长期稳定性分析

Similar experimental construction and long-term stability analysis of horizontal salt caverns

利用地下盐穴作为油气储库是一种常见的方法。但由于中国地下盐矿层状盐岩居多,特点是单层厚度薄,不溶物含量高,因此单井造腔腔型控制难度大,造腔速度慢。根据双井对流建库方法,通过实验模拟建造的水平盐穴为模型基础,依据湖北云应地区盐矿地质条件和盐岩的物理力学性质,数值模拟其在不同埋深情况下建造后腔体长期运行体积收缩情况。通过实验发现采用双井对流造腔方法建设储气库是可行的,腔体的形状可以通过流量和油液分界面来控制。对地下盐岩水平储气库的岩石长期蠕变模拟发现,水平储气库随着埋深越大相同蠕变期内条件下腔体的体积收缩率和腔体周边塑性变形区体积也越大,同时使用寿命也越短。

Using underground salt cavern for oil and gas storage is a common practice. Due to the characteristics of underground salt mines in China, which are rich in bedded salt rock, thin in terms of thickness and combined with high volume of insoluble non-salt rock, the shape control of single-well cavern construction is inevitably difficult and the construction takes a long time. Using experimental simulation construction of the horizontal salt cavern as a basic model, and taking the geological and physically mechanical conditions of salt caverns in Yunying, Hubei province into consideration, we numerically simulated the long-term rock creep effect under different buried depths with the twin-well cavern construction method. The simulation results show that the construction method is applicable, and the shape of cavern can be controlled through flow and fluid interface. It＇s also found during the same time in which rock creep takes effect, the deeper the cavern is buried, the higher the shrinkage rate of the cavern is, and the larger the plastic deformation zone around cavern becomes, which finally result in the shorter service life of the salt cavern for horizontal gas storage.