A survey of the literature related to theoretical and experimental studies on stick–slip
vibration in oilwell drillstring is carried out in this study. It aims to explain key concepts and …

A distributed model of a drill string is presented, with Coulomb stiction as a distributed
source term, to investigate the effect of borehole inclination and borehole friction on the …

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) …

We design and test an algorithm for estimating the bit angular velocity and side forces on a
drill string using only topside measurements fed into an adaptive observer. To derive the …

Drilling is an important means of obtaining resources. Since the complicated bottom hole
conditions and coupling relationship among subsystems, it is difficult to accurately predict …

We have developed a sensing and computational framework to estimate seismic velocities
of rocks interacting with the drill bit during the drilling process. The performance of drilling …

The mud pit volume (MPV) model is of great importance in evaluating the bottom hole
pressure (BHP). In this paper, an online hybrid model is developed to predict MPV …

A lumped element model for the axial movement of an oil-well drillstring is presented. In this
paper, the model is restricted to vertical holes, where damping is due to skin friction from …

Horizontal well is one of the important methods of unconventional oil and gas resource
development. As increasing length of horizontal section, there is a serious problem that axial …

The lumped element model of the axial movement in a drillstring that was developed in
Ref.[1], is extended to apply for deviated wellbores. This extension involves taking into …