不同腔形下盐岩储库区地表最大变形预计新方法

众多已有盐穴地下储库群地面沉降监测数据和灾变实例表明盐穴储库群地面变形预测与控制是保证储库长期安全稳性运营的关键问题之一。中国盐岩地层盐层薄、成层分布的特点加剧了库区地表发生沉陷的灾变程度，直接影响到中国盐穴地下能源储备的安全。采用 Gaussian 曲线表示沉降分布，结合腔体收敛函数，建立了一套有别于概率积分法的地表变形预测理论—传递函数法。在此基础上，结合中国盐岩地层特点，对比计算了相同体积下椭球形、梨形与圆柱形溶腔在发生腔体完全收敛时所导致的地表最大变形量，并利用迭加原理对不同腔群分布形式、不同腔体间距下库区地表最大沉降进行了比较。研究认为，当单腔发生完全收敛时椭圆形腔体造成的地面沉降量最小，圆柱形最大；而库群对比计算结果表明腔体中心间距的增加将导致最优腔形的变化，并非椭圆形腔体始终最优。研究成果为中国油气储库建设中库区地表变形预测、腔体形状和布局优化以及相关规范的制定等方面提供了理论依据。

New prediction method for maximum surface deformation in salt rock storage field considering different cavity geometries

The prediction and control of the surface subsidence above rock salt storage caverns is one of the key problems to ensure the long-term safely stable operation,which has been proved by in-situ monitoring data and catastrophe examples of the existing rock salt underground storage caverns.The salt stratum in China has characteristics as follows: thin salt layer and bedded sediment,which not only increases the damage extent of surface subsidence occurrence,but also directly influences our energy storage scale.Based on the Gaussian distribution theory and combined with convergence function,a new surface deformation prediction theory,transfer function method,is established,which is different from the probability integration method.On this basis,according to the salt strata characteristics in China,elliptic cavity,pear-shaped cavity and cylindrical cavity,which have the same volume,are chosen to compare the maximum surface deformation induced by the cavity completely converged.In addition,the superposition theory is employed to calculate the maximum subsidence in the field with different cavity layouts and different interval distances between cavities.The elliptic cavity is better than the other two kinds of cavities when the single cavity is completely converged.However,when considering to increase the distance between two cavities,the elliptic cavity will not be the best all the time.The research results will provide a reliable theory support for the surface deformation prediction,optimization of cavity shape and cavity layout and relative instruction about rock salt cavity construction in China.