Modeling and prediction of hole profile in drilling, part 2: Modeling hole profile

A hole profile model that integrates the dynamics of the drill in the presence of alignment errors, the drill wandering, and the drill margin-hole wall interaction has been developed. The ultimate profile of the hole is generated by the vibrations of the drill at its tip due to its dynamics and wandering, and by the continual updating of the already generated surface to account for any potential drill margin-hole wall interaction. The model predicts the lobbing pattern of the hole in close agreement to that observed during the experiments. The effect of the drill dynamics in the presence of alignment errors, drill wandering, drill margin-hole wall interaction as well as the individual effect of the alignment errors (alpha, phi, and gamma) has been studied.