Nonlinear control design for suppressing stick-slip oscillations in oil well drillstrings

This paper presents a controller for a rotary drilling system, that is derived from input-state feedback linearization based approach, and by considering the stick-slip motion of the bit on the bottom hole assembly (BHA) in oil wells. As known, this is a complex problem where the torque exerted on bit is a function of the bit speed that is a state variable. In this work, we proposed a feedback linearization controller which enables to suppress the stick slip oscillations. The success of the applied approach is demonstrated through the resultants simulations.