Finite Element analysis of drill pipe-slip system

As an important tool for tripping of a drill-string, a drill-pipe (DP)-slip system directly affects both the service life of a DP and the target depth it can reach. In this paper, a finite element (FE) model developed in ABAQUS is used to simulate interactions within a DP-slip system. For this model, materials, geometric dimensions, loads, and boundary conditions were determined for an actual DP-slip system. A special attention was paid on the stress field of the slip insert and the DP focusing on the geometric parameter optimization of the slip insert with regards to the stress distribution, wherein factors like a longitudinal groove number in slip insert, a number of slip inserts, and a number of row spacing of slip inserts are considered. Numerical results show that the circumferential stress and axial distributions change for both the DP and slip inserts, and that the stresses of the inner surfaces are higher than that of the outer surfaces. Effects of geometric parameters of the slip insert on the stress distributions of both DP and slip insert are studied and the corresponding optimized values are obtained, which can be used for the designing of slip insert.