Drill-string nonlinear dynamics accounting for the drilling fluid
Résumé
The influence of the drilling fluid (or mud) on the drill-string dynamics is analyzed in this paper. Usually the presence of the fluid is not taken into account in the analysis of the nonlinear dynamics of a drill-string. The aim of this paper is to investigate how the fluid affects this dynamics using a simplified fluid-structure interaction model that takes into account the fluid that flows downward inside the column and then upward in the annulus. For the column, the proposed model considers the Timoshenko beam theory with finite strain (all the terms of the Green-Lagrange tensor are used). When finite strains are considered, the axial, lateral and torsional vibrations become coupled. A bit-rock interaction model that describes how the bit penetrates the soil is used and there might be impact and rubbing between the column and the borehole. The system of equations is discretized by mean of the Finite Element Method. It turns out that the fluid has an important influence on the drill-string dynamics, especially for the lateral vibrations.
Fichier principal
conference-2009-CILAMCE-buzios-Brazil-ritto-sampaio-soize-Preprint.pdf (724.67 Ko)
Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...