On the stochastic bit–rock interaction disturbances and its effects on the performance of two commercial control strategies used in drill strings

Lobo, DM, Ritto, TG, Castello, DA and Batou, A (2022) On the stochastic bit–rock interaction disturbances and its effects on the performance of two commercial control strategies used in drill strings. Mechanical Systems and Signal Processing, 164. p. 108229.

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Official URL: http://dx.doi.org/10.1016/j.ymssp.2021.108229

Abstract

The vibration of drill strings is a well-known source of undesirable disturbance in drilling operation, therefore it is important to design and evaluate active controllers to suppress it. The drill string dynamics is complex due to nonlinear interactions with the environment, and the uncertainties related to them. This paper aims to analyze two commercial control strategies acting at the top drive, namely stiff controller and SoftSpeed, applied to a pure torsional drill string model that takes into account uncertainties in the bit–rock interaction. The model is calibrated with field data and the numerical results present a good agreement with the measurements. Uncertainties in the torsional vibration severity are assessed through severity maps. Finally, the effect of the uncertainty level on the control strategies is analyzed. Although SoftSpeed gives better results, it is clear that the controller becomes less effective in suppressing vibrations as the uncertainties increases.

Item Type:	Article
Uncontrolled Keywords:	Drill string, Stochastic, Control, Stick-slip, Robust, Calibration
Divisions:	Faculty of Science and Engineering > School of Engineering
Depositing User:	Symplectic Admin
Date Deposited:	06 Sep 2021 09:07
Last Modified:	18 Jan 2023 21:30
DOI:	10.1016/j.ymssp.2021.108229
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3136062