摘要
地下盐穴储气库围岩变形机理是地质可储性的关键问题。针对平顶山盐田盐层薄、夹层多以及埋藏深等特征,分别采集了纯盐岩、互层状盐岩、泥岩夹层三种岩石试样,进行了不同应力水平下的单轴和三轴压缩蠕变试验。蠕变试验结果表明,单轴和三轴状态下三种试样的蠕变均呈现初始蠕变和稳态蠕变两个阶段,互层状盐岩的初始蠕变时间相对较长,稳态蠕变率处于盐岩和泥岩之间,其变形主要由盐岩层贡献,同时层间变形的不协调导致互层状盐岩在稳态蠕变阶段出现泥岩夹层的颈缩内陷和盐岩层的膨胀外突破坏现象。根据互层状盐岩的蠕变特征,建立起蠕变模型,并根据试验数据拟合出模型参数。分析结果表明,理论模型和试验数据吻合较好,拟合参数完全佐证了上述互层状盐岩的蠕变特殊性,为盐田安全建立地下储气库提供一定的参考依据。
Deformation mechanism of surrounding rocks of the underground salt cavity gas storage is the key problem to the geological storage capacity. Aiming at such characteristics of the Pingdingshan salt field as thin layer,more interbedded layers and deep burial,three kinds of samples namely,pure salt rock,interbedded salt rock and interlayered mudstone,were collected,and uniaxial and triaxial creep experiments were conducted under different stress levels. Results of the creep experiment show that the creep of the three kinds of samples can be divided into two phase including initial creep and steady creep under the uniaxial and triaxial states,the initial creep time of interbedded salt rock is relatively long,and the steady creep rate is between salt rock and mudstone. The deformation is mainly contributed by salt rock,while the disharmony deformation between layers of interbedded salt rock can lead to narrowing of mudstone and expansion of salt rock in the steady creep phase. Based on the characteristics of interbedded salt rock,the creep model is established and the parameters are fitted by the experiment data. The results indicate that the theoretical model is in good agreement with the experiment data. The analyses of this paper reflect the particularity of the creep of interbedded salt rock and can provide some reference to the establishment of underground gas storage.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2014年第5期125-130,137,共7页
Hydrogeology & Engineering Geology
