The drilling industry has substantially improved performance based on knowledge from
physics-based, statistical, and empirical models of components and systems. However, most …

In this paper, the output feedback stabilization of an underactuated chain of scalar
hyperbolic systems coupled at one end with a finite-dimensional system is addressed. As …

This paper demonstrate the feasibility and illustrates some challenges of applying extremum
seeking control to online optimization of the drilling process. Specifically, we consider the …

Digitalization of the drilling process has the potential to improve drilling data quality and
consistency, providing support for drilling optimization, safety and efficiency. A significant …

The use of recorded downhole rotational speed measurements with a bandwidth up to 9 Hz
gives new insights into the conditions under which stick-slip torsional oscillations occur …

During drilling operations, drillstring vibrations cause many downhole dysfunctions, resulting
in underperformance, equipment failure, and possibly wellbore damage. Current drillstring …

During recent years there has been an increased focus on automating drilling operations
and several solutions are in daily use. We describe here results and lessons learned from …

In this paper, we consider the axial motion of a directional multi-sectional drill-string. The drill-
string dynamics are represented by a distributed dynamical model (wave equations) …

This article proposes a control strategy to stabilize the axial–torsional dynamics of a
distributed drill-string system. An infinite-dimensional model for the vibrational dynamics of …

A drill-string is an extremely slender mechanical structure and consequently it can oscillate
very easily. Drill-string vibrations during drilling operations is the source of many drilling …