The motion of drill strings is modeled in the drilling geotechnological wells mining industry by Lumped-Parameter Method (LPM). This method widely used structural mechanics and most justified modeling dynamic systems with a variable structure. On example horizontal wells, longitudinal vibrations string static compressive load at left end are considered [1]. contact interaction borehole walls in...

This paper formulates the ramp metering control problem as a real-time feedback control problem. The development is shown by modeling freeway sections, and hence the results are immediately applicable to isolated ramp metering problems. The ideas presented in this paper can be utilized to develop coordinated ramp metering feedback control techniques. Three different forms of the formulation for...

This work aims at studying the nonlinear dynamics of drill strings using lumped-parameter method (LPM). The study is based on good consistency results test problem where model longitudinal vibrations a horizontal string with static compressive load left end considered. In this paper, applied to discretize linear and models lateral vertical under effect supersonic gas flow. obtained are verified...

The present paper extends the so-called Effective Process Time (EPT) approach to single server flowlines with finite buffers and blocking. The power of the EPT approach is that it quantifies variability in workstation process times without the need to identify each of the contributing disturbances, and that it directly provides an algorithm for the actual computation of EPTs. It is shown that E...