Numerical simulation of the drill string buckling behavior in horizontal wells considering the orthotropic friction
Keywords: Drill string, Finite element, Orthotropic friction, Buckling behavior
AbstractThe effect of the friction between the drill string and the borehole on the drill string buckling behavior has not been fully understood. First, we treated the friction between the drill string and the borehole as the orthotropic friction, and established a finite element (FE) model of the drill string and the borehole system. Then, the comparison with the experimental results shows that the FE model has a high accuracy. Finally, the effect of the orthotropic friction on the buckling behavior of the drill string was analyzed. Results demonstrate that the orthotropic friction can impact the buckling behavior, such as the critical buckling forces, the bending moment, the friction force and the axial force transfer. Simplifying the friction between the drill string and the borehole as the unidirectional or the isotropic friction cannot accurately predict the buckling behavior. The results can complement the existing theoretical models and provide guidance for field operations.