In this article, an integrated model with spatially distributed inertia and general boundary
conditions for the axial-torsional dynamics of a drill string is developed and studied. Based …

In this paper, a reduced-order drill-string model with coupled axial and torsion dynamics is
studied. Nonlinear effects associated with dry friction, loss of contact, and the state …

Nowadays, drill string technologies are among the leading fields in the industries of oil and
gas extraction and are widely used in the construction of subway tunnels. Due to their …

Drilling depths exceeding 10,000 m have recently been achieved, but the increasing depth
poses challenges due to the flexible drill-string, making it more susceptible to stick-slip …

Objective To propose a model for the coupled axial-torsional dynamics of a drilling bit with a
non-uniform blade arrangement and to investigate the effects of multiple-regenerative effects …

This paper extends the RGD model originally proposed by Richard et al.(J Sound Vib 305
(3): 432–456, 2007, https://doi. org/10.1016/j. jsv. 2007.04. 015) to investigate drilling …

Stick‐slip vibration reduces the drilling rate of penetration, causes early wear of bits, and
threatens the safety of downhole tools. Therefore, it is necessary to study suppression …

This article investigates the stability problem of impulsive stochastic switched systems with
double state-dependent delays. In the designed system, unstable and stable impulses are …

One approach to analyze the stick-slip vibrations of a rotary drilling system with a PDC bit is
based on the RGD model (Richard et al., 2007), a discrete model that assumes a rate …

ABSTRACT A specific model is elaborated for stick-slip and bit-bounce vibrations, which are
dangerous dynamic phenomena typically encountered in the context of rotary drilling …