Modeling and friction response analysis of rocking-sliding friction of drill string in directional wells

The main goal of this research is to conduct a quantitative assessment of how rocking influences friction during sliding. The kinetic equations were developed, accounting for the friction coefficient's velocity weakening effect. The model's precision and dependability were confirmed by comparing simulation results against experimental data. Furthermore, the study discovered that the Stribeck model presents benefits when compared to alternative models. Investigations were carried out to examine how rocking parameters affect axial friction during rocking motions. The findings indicate that variations in axial friction forces are predominantly observed during the phase of tangential acceleration. Crucially, the research demonstrates that modulating the rocking velocity's waveform can markedly decrease the average axial friction, even when the maximum rocking speeds remain the same.