Drilling is a complex process. The drillstring may have more than 10km and are very flexible. The bottom hole assembly, on the bottom of the drillstring, is short but is under heavy compression and subject to a very complex load. Besides the complexity, the drilling process and structures involved are very uncertain. Specially in the interaction between soil that is being drilled and the drill. The main type of uncertainty is in the stick-slip dynamics that must be mastered in order to control the drilling process and optimize the rate of penetration of the drill.
The talk will discuss the drilling process, how the modeling process developed in Brazil, its uncertainties, its stability and reliability, and will concentrate in the stick-slip dynamics and how to model it.
