Drill string instability reduction by optimum positioning of stabilizers

作者:Mahyari M F*; Behzad M; Rashed G R
来源:Proceedings of the Institution of Mechanical Engineers - Part C: Journal of Mechanical Engineering Science , 2010, 224(C3): 647-653.
DOI:10.1243/09544062JMES1566

摘要

The main aim of this article is to find the optimum positions of the stabilizers that reduces the vibration and leads to the largest weight on bit (WOB) in drill strings. In this work, the potential energy of drill strings has been derived by considering the drill string weight and WOB. The potential energy of this continuous system is considered as a multi-degree-of-freedom system by the mode summation method. The equilibrium position of the system and its stability is determined by finding the roots of the first derivative and the sign of the second derivative of the potential energy, respectively. Using this formulation, the best positions of stabilizers that lead to the largest WOB can be found for different numbers of stabilizers. The best arrangement of the stabilizer's position on a drill string with one, two, and three stabilizers is investigated.