Buckling of Drill Pipe in an Inclined Hole

The buckling of drill pipe in the vertical plane for the case of an inclined hole is studied. This is accomplished by performing a stability analysis of a simply supported column lying in compression on a rigid inclined plane in the presence of a gravity field. The lateral displacement of the column is restricted to be perpendicular to the plane. According to the results of an approximate analysis it is found that the system becomes unstable under the above conditions only if the lateral variational displacements are finite. The derived stability equation is verified for a particular case by a simple experiment. The results of this analysis can be used to determine the “crookedness” of a hole which, under specified conditions, will induce instability.