Active Damping of Spatio-Temporal Dynamics of Drill-Strings

Abstract

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.