层状盐岩蠕变变形差异性及附加应力  

Creep deformation difference of bedded salt rocks and its additional stress

作　　者：马纪伟[1] 王芝银[1] 郑雅丽[2] 赵艳杰[2] 

机构地区：[1]中国石油大学城市油气输配技术北京市重点实验室,北京102249 [2]中国石油勘探开发研究院廊坊分院,河北廊坊065007

出　　处：《石油学报》2014年第1期178-183,共6页Acta Petrolei Sinica

基　　金：国家重大科技专项"钻井压裂适度出砂油藏工程技术"(2008ZX05024-003)资助

摘　　要：基于伯格斯(M-K)蠕变模型,根据三维压缩蠕变实验条件,建立了层状盐岩轴向蠕变本构方程;推导出各单层岩性蠕变参数与整个层状盐岩样的蠕变参数关系表达式;同时,在建立层状盐岩径向蠕变本构方程的基础上,推导出层状盐岩各岩层由于蠕变变形差异产生的附加力求解公式;依据淮安库区某层状盐岩蠕变实验数据对所得到的结果进行了部分验证。研究表明,层状盐岩的蠕变破坏是岩层由于蠕变变形差异产生附加力与其作用方向上应力共同作用的结果,只有当其合应力超过夹层抗拉强度时,才会使盐岩夹层发生张拉破坏。研究结果为层状盐岩体中地下盐穴储气库的长期稳定性评价提供了理论分析基础。The emergence of deformation incompatibility arising from different creep properties of pure and interbedded salt rocks may lead to the deterioration of mechanical properties of bedded salt rocks, which has a significant impact on the stability and safe opera- tion of salt-cavern gas storage. Based on the Burgers （M-K） creep model, we established an axial creep constitutive equation of bed- ded salt rocks for the three-dimensional compression creep test conditions, and deduced a relational expression for creep parameters of each individual rock bed and the whole bedded salt rocks. Meanwhile, on the basis of the radial creep constitutive equation of bed- ded salt rocks, a solution formula for the additional stress arising from the creep deformation difference of bedded salt rocks was also deduced and the results obtained were partially verified by creep test data derived from a salt-rock bed in the Huai＇an reservoir area. Studies have shown that the creep damage of bedded salt rocks results jointly from the additional stress arising from the creep de- formation difference and the stress in the same direction of the effect. Only when this co-stress exceeds the interlayer tensile strength, can an interlayer tensile failure of salt rocks happen. The results will provide a theoretical foundation for evaluating the long-term stability of underground salt cavern gas storage in bedded salt rocks.

关 键 词：层状盐岩 蠕变变形差异 本构方程 参数 附加应力 

分 类 号：TU45[建筑科学—岩土工程]