ℒ1 Adaptive Control for Directional Drilling Systems

This paper considers downhole directional drilling systems in the presence of unexpected variations in steering force, input delays, measurement noise and measurement delays, and explores the application of ℒ1 adaptive controller for the trajectory control problem. The Explicit Force, Finitely Sharp, Zero Mass (EFFSZM) model is used for the steering system, in which spatial delays, modeling inaccuracies, parametric uncertainties, and noise are considered. The ℒ1 adaptive controller ensures that the centerline of the borehole follows a well path planned according to a priori available geologic conditions and local residential information. Path tracking results are demonstrated by simulations.