非均匀地应力下蠕变地层套管的载荷与变形关系

摘要

Casing loads and deformation are mutual influence factors in creep stratum.The analytical solution of creep stratum' s casing loads and deformation in non-uniform stresses is studied, which is one of the main factors to damage casings.It is very hard to calculate the finally steady casing loads and final casing deformation effected by the creep stratum in non-uniform stresses.The casing is taken as the elastic foundation and the stratum as infinite viscoelastic foundation, and then a Kelvin model of creep stratum is built to analyze the casing loads in non-uniform stresses.The distribution rules of creep stratum' s casing loads in non-uniform stresses is perfected and then the analytical solution of casing deformation is got by semi-inverse methods and Laplace transform methods.The distribution of creep stratum' s casing loads and impact factors of casing deformation are studied in non-uniform stresses.The conclusion is valuable to the selection of casing used in creep stratum.%蠕变地层中套管载荷与套管变形是两个相互作用的因素,给出了非均匀地应力下蠕变地层套管载荷和变形的解析解.地层蠕变效应是引起各类套管大量损坏的主要原因之一,在非均匀地应力下,如何计算蠕变地层作用于套管上的最终稳定载荷和套管最终变形,这是两个很难解决的课题.将套管看成弹性体,把地层视为无穷大的黏弹性体,利用非均匀地应力条件下蠕变地层的开尔文模型本构关系,运用半逆解法和拉普拉斯变换法,完善了非均匀地应力条件下蠕变地层套管载荷的解析解,进而求出了套管变形的解析解；研究了非均匀地应力下蠕变地层中套管载荷的分布规律和变形的影响因素.结论对蠕变地层中套管的选用有重要的参考价值.