Torque Feedback Used to Cure Slip-Stick Motion (1988)

Torque Feedback Used to Cure Slip-Stick Motion G.W. Halsey; G.W. Halsey Rogaland Research Inst. Search for other works by this author on: This Site Google Scholar A. Kyllingstad; A. Kyllingstad Rogaland Research Inst. Search for other works by this author on: This Site Google Scholar A. Kylling A. Kylling Rogaland Research Inst. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, October 1988. Paper Number: SPE-18049-MS https://doi.org/10.2118/18049-MS Published: October 02 1988 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Halsey, G.W., Kyllingstad, A., and A. Kylling. "Torque Feedback Used to Cure Slip-Stick Motion." Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, October 1988. doi: https://doi.org/10.2118/18049-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractA novel idea to control the rotary speed incorporates the torque signal, in addition to the speed signal, to produce a more uniform motion of the drillstring. This produce a more uniform motion of the drillstring. This method is easily incorporated into existing equipment used to control the rotary speed.We have tested this control system on a full-scale research drilling rig and have demonstrated that such a system can stop slip-stick motion and prevent it from starting. As an additional benefit, such a control system leads to smoother rotation of the bit which can lead to a reduction in axial and lateral vibrations of the drillstring.In this paper we present the theoretical basis behind such a system and give an example of the experimental results.IntroductionTorsional drillstring vibrations, in particular slip-stick oscillations, have been studied intensively in the last few years. Frequency analysis of the driving torque has shown that a large number of peaks in the torque spectrum can be identified as torsional drillstring resonances. The sharpness of the resonance features indicates that there is little damping of such vibrations.Slip-stick motion of the bottom hole assembly can be regarded as extreme, self-sustained oscillations of the lowest torsional mode, called the pendulum mode. Such a motion is characterized by finite time intervals during which the bit is non-rotating and the drillpipe section is twisted by the rotary table. When the drillstring torque reaches a certain level (determined by the static friction resistance of the bottom hole assembly), the bottom hole assembly breaks free and speeds up to more than twice the nominal speed before it slows down and again comes to a complete stop. It is obvious that such motion represents a large cyclic stress in the drillpipe that can lead to fatigue problems. In addition, the high bit speed level in the problems. In addition, the high bit speed level in the slip phase can induce severe axial and lateral vibrations in the bottom hole assembly which can be damaging to the connections. Finally, it is likely that drilling with slip-stick motion leads to excessive bit wear and also a reduction in the penetration rate.It is therefore desirable to cure, or at least to reduce, the torsional vibrations in the drillstring.P. 277 Keywords: rotary drive, kyllingstad, slipstick motion, upstream oil & gas, reflection coefficient, vibration, drillstring design, oscillation, torque signal, torsional wave Subjects: Drillstring Design, Torque and drag analysis This content is only available via PDF. 1988. Society of Petroleum Engineers You can access this article if you purchase or spend a download.