A Buckling Criterion for Constant-Curvature Wellbores

Summary This paper examines the effect of wellbore curvature on the buckling stability of casing. A large-displacement/small-strain analysis was used to obtain a general stability result, including all curvature effects. Two types of analysis are provided for comparison and contrast. The first analysis is an equilibrium analysis, which provides not only the stability criterion desired, but additional information, such as the contact force between the casing and the wellbore. The second analysis is an energy balance. This analysis was developed to provide a comparison with other stability results, some of which differ from the calculations presented here. Previous papers investigating this problem have produced conflicting results. This paper resolves the conflict.