Fractional-order controllers for stick-slip vibration mitigation in oil well drill-strings Academic Article uri icon


  • Drillstringborehole interaction can produce severely damaging vibrations. An example is stickslip vibration, which negatively affects drilling performance, tool integrity and completion time, and costs. Attempts to mitigate stickslip vibration typically use passive means and/or change the operation parameters, such as weight on bit and rotational speed. Automating the latter approach, by means of feedback control, holds the promise of quicker and more effective mitigation. The present work presents three separate fractional-order controllers for mitigating drillstring slipstick vibrations. For the sake of illustration, the drillstring is represented by a torsional vibration lumped parameter model with four degrees of freedom, including parameter uncertainty. The robustness of these fractional-order controllers is compared with traditional proportional-integral-derivative controllers under variation of the weight on bit and the drill bits desired rotary speed. The results confirm the proposed controllers effectiveness and feasibility, with rapid time response and less overshoot than conventional proportional-integral-derivative controllers.

published proceedings


author list (cited authors)

  • Derbal, M., Gharib, M., Refaat, S. S., Palazzolo, A., & Sassi, S.

citation count

  • 5

complete list of authors

  • Derbal, Massinissa||Gharib, Mohamed||Refaat, Shady S||Palazzolo, Alan||Sassi, Sadok

publication date

  • September 2021