基于孔隙变形泥岩蠕变细观损伤模型

Model of mesoscopic damage based on deformation of the pore on mudstone creep

为对后续套管损坏力学研究提供新的研究方向,提出一种运用孔隙变化作为细观损伤变量描述泥岩蠕变变形特征,确立宏观损伤变量与细观损伤变量本质关系,并建立基于细观损伤变量的泥岩蠕变损伤本构模型.选取长庆油田石盒子组泥岩岩样作为工程实例,得出泥岩蠕变损伤岩体理论应力与应变本构关系,理论计算应力和实验测定应力相比,最大误差为9.204%,计算结果与实际吻合较好.

To provide new research direction for the subsequent casing damage mechanics research, the paper presents a new method which uses porosity as damage variable to describe mudstone creep. We obtained the relationship between macroscopic damage variables and the mesoscopic damage variable, established mudstone creep damage constitutive model based on mesoscopic damage variable. In this paper, we take Changqing oil field stone box group mudstone rock specimen as example, getting stress-strain constitutive relationship of mudstone creep damage. After comparing theoretical calculation with practical results, the maximum error was 9.204%, and the calculated results are in good agreement with the actual ones.