Active Damping of Spatio-Temporal Dynamics of Drill-Strings
- 1.2k Downloads
In the drilling process for the exploration of oil and gas resources a variety of vibration phenomena occur. Here, just self-excited torsional vibrations and forced flexural vibrations of the drill-string are considered. An experimental setup which models a real drill-string was designed and constructed. The aim is to actively damp these vibrations. The string of the setup was modeled as a one-dimensional continuum. The resulting equations of motion were approximated using Galerkin’s method. Reducing the system’s order by applying the proper orthogonal decomposition results in only one coordinate which is fed back in order to actively damp the system.
Key wordsModelling stick-slip vibrations optimisation nonlinear control
Unable to display preview. Download preview PDF.
- O. Kust. Selbsterregte Drehschwingungen in schlanken Torsionssträngen. Nichtlineare Dynamik und Regelung. Fortschr.-Ber. VDI, Reihe 11, Nr. 270. VDI Verlag, Diüsseldorf, 1998.Google Scholar
- A. I. Lurie, Analytical Mechanics, Berlin, Springer, 2002.Google Scholar
- L. E. Malvern, Introduction to the Mechanics of a Continuous Medium, Prendice-Hall, London, 1969.Google Scholar
- L. Meirovitch, Analytical Methods in Vibrations, The Macmillan Company, New York, 1967.Google Scholar
- R. Nelder and J.A. Mead, “A simplex method for function minimization,” Computer Journal, 7:308–313, 1965.Google Scholar
- R. Walter, Differentialgeometrie, BI-Wissenschaftsverlag, Mannheim, Wien, Zütrich, 2. edition, 1989.Google Scholar