Delay system modelling and analysis of a down-hole tool in drilling system

Abstract

In this abstract, we present a delay systems model for the coupled axial-torsional dynamics of a drilling system including a down-hole tool. The down-hole tool directly affects the coupling between the axial and torsional dynamics and aims to improve the rate-of-penetration of the drilling system, thereby improving drilling efficiency. The results presented here provide physics-based insight in the working principle of the tool and confirm that indeed drilling efficiency can be improved by its usage