LAUSR

In hydrocarbon well-drilling operations, self-excited, stick-slip vibration is considered as a source of drilling equipment failures, which also causes a reduction in the drilling penetration. This leads to delays and increase in the operational and equipment costs. A new approach using distributed-lumped (hybrid) modelling is considered as the first step in understanding the stick-slip phenomena in order to determine a solution to this problem. In this paper, a hybrid modelling scheme is the advocated modelling method proposed in contrast to the conventional lumped modelling. Three case studies are used to show that hybrid modelling is an accurate technique in the representation of stick-slip oscillations, particularly when the length of the drill string is high. The results show that the modelling technique adopted in this work can more accurately present the phenomena associated with stick-slip process.