Casing deformation occurs frequently during the development of the Weirong Shale Gas Field in the Sichuan Basin.In order to solve this problem

analysis on load and deformation degree of three casing deformation has been carried out by finite element method to discuss the deformation type.Meanwhile

by means of theoretical analysis

finite element simulation and equivalent test evaluation

the quantitative analysis is carried out on the parameters such as the overall angle change rate

cementing quality

wellbore temperature-pressure change and instantaneous stop pump.The influence of different engineering factors on casing strength weakening shows that the engineering factors are not the main factors of casing deformation.According to the analysis of comprehensive factors in the transformation process such as formation anisotropy

wellbore temperature-pressure coupling and reservoir lithologic interface

it is considered that the casing strength decreases under engineering conditions

"while in the process of fracturing

the slip of " weak strata or the non-uniform compression load of reservoir on casing leads to casing stress concentration and deformation.The relevant understanding provides a reference for the formulation of casing deformation prevention and control measures of Weirong Shale Gas Field.