Damping Optimum Tuning of Drill-string Torque-based Torsional Vibrations Suppression System

The paper presents the design methodology and experimental verification of petroleum drilling system aimed at effective suppression of drill-string torsional vibrations. The vibration suppression system is based on the external damping feedback loop featuring a simple drill-string torque estimator and a reference correction term in the speed target path. The feedback control system design is based on the damping optimum criterion, which results in straightforward analytical expressions for controller parameters. The overall control system is also extended with drill-string drive back-spinning prevention system which detects the hazardous stuck drill-string conditions and timely initiates drill-string unwinding and safe drive stopping. The effectiveness of the proposed control strategy is verified experimentally on a down-scaled laboratory setup.