Hybrid Backstepping Sliding Mode Controller for Stick–slip Vibrations Mitigation in Rotary Drilling Systems

Abstract

The main objective of this paper is to suppress the stick–slip vibrations in the drilling system so that the drill bit can follow the desired nominal angular velocity of the Top Drive in an optimal time. Hence to protect drilling equipment from hazards and increase drilling performances by decreasing the non-productive time (NPT). Three control systems have been proposed to achieve this objective, a sliding controller is firstly designed and then a backstepping approach is discussed secondly. Furthermore, a hybridization of sliding mode control with a backstepping approach has been proposed on the so-called hybrid backstepping sliding mode controller. The latter has not been proposed before in the literature for rotary drilling systems. Moreover, two torsion models of the system have been discussed for different degrees of freedom. Based on the comparison between controllers’ responses, the effectiveness and the robustness of the hybrid controller have been demonstrated and highlighted, whose fast response can protect the drilling equipment from hazards that may be caused by the slip phase of the vibrations. Hence, it is recommended to implement the proposed controller in smart rotary drilling systems for petroleum industry.