近置已有盐岩溶腔能源地下储库群特性研究

针对我国须采用密集库群来提高油气地下存储中资源利用率的现状，对近置已有盐岩溶腔库群运营模式下储库稳定性和收缩变形展开了研究。基于声纳测腔成果，建立了符合实际存在的单腔模型及库群模型。对模拟结果进行了对比分析，明确了库群运行模式对储库稳定性的影响规律。发现储库相对位置和深度的差异、夹层地层倾角的存在、相邻储库体积和形状的不等同3个因素会导致某些腔体的收缩变形不对称、腔体形变不规则；不同于单腔的最大位移区域固定出现在腰部，库群模式下受周围腔体的影响，而并无固定的腔壁位移最大点位置；呈现板状存在贯穿整个库群的泥岩刚度大、蠕变性能低，并且其和盐岩交界面的抗剪能力较强，可以提高库群的整体性和稳定性；考虑地层倾角的夹层变形特性成为对库群密闭性不利的影响因素，泥岩-盐岩交接面的拉伸以及泥岩夹层本身的扭转弯曲会使泥岩层产生裂隙，贯通的裂隙可导致各个腔体失去独自运行的能力，影响储库运行效率

Behaviors of existing salt cavern group used for underground energy storage

Due to the situation that intensive cavern group system has to be used to improve resources(oil & gas) storage efficiency in China,the stability and contraction distortion of the existing salt rock storage group model are discussed.The single cavity model and cavern group model are built according to the result of sonar cavity survey,and the influence laws that how cavern group operating model effects the cavern stability are proposed through the comparison and analysis of the simulation results.The laws show that asymmetric volume shrinkage and irregular deformation can be induced by the following three factors,the difference in position and depth,formation dip of interbedded and shape difference between adjacent cavern;different from which the maximum displacement zone usually appeared in a fixed position near the waist in single cavern model;there are no fixed position of maximum displacement because of the influence of nearby caverns in the cavern group model;with the properties of high stiffness,low creep resistance and the strong shear strength near the salt-mudstone interface,the mudstone can improve storage cavern integrity and stability when it penetrates the whole cavern group;considering that the stratigraphic dip interlayer deformation property has bad influence on the cavern group leakproofness,the stretching at the mudstone-salt interface and the torsional bending of mudstone can cause cracking in the mudstone layer: and the breakthrough crack could make single cavern lose the ability to operate alone and then affect the whole operating efficiency of the cavern group.