April 25, 2022 – 8:30am Central Time
Coupled Drillstring Model for Drilling and Stick-slip vibrations in drilling: modeling, estimation, avoidance
Monday, April 25, 2022
8:30 am – 9:30 am Central DaylightTime
Speaker: Jean Auriol (Université Paris-Saclay) and Florent Di Meglio (MINES ParisTech)
In this talk, we present some recent developments for estimating and controlling the torsional motion of a drilling device. We introduce first the stick-slip phenomenology and explain its physical causes. We present a mathematical distributed model that can accurately describe the torsional motion of the drilling device. We then focus on the case of a drilling system with the bit off-bottom, which represents the system at the start-up of a drilling operation, e.g., after a connection. 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. The proposed approach combines a high-fidelity model with recent theoretical developments on observer design for hyperbolic PDEs to find appropriate feedback gains to ensure a fast and robust tuning. The estimates produced by the algorithm can be displayed to a driller in real-time in an advisory system, and the result can be built on to help optimize the drilling operation and improve directional drilling control. We finish this presentation by comparing recent advanced control strategies to eliminate stick-slip oscillations. The different results are illustrated by simulation with field scenarios and tests against field data.