Tube-Based Adaptive Model Predictive Control for Deviation Correction in Vertical Drilling Process.

The build-up rate of the bottom hole assembly (BHA) fluctuates violently during the deviation correction in the vertical drilling process due to the mutation of stratum, low operation accuracy of the BHA, etc. As a result, the uncertainty of the build-up rate of the BHA has great influence on the performance of correction control and the quality of the drilling trajectory. To deal with this control problem, a tube-based adaptive model predictive control (MPC) method is developed in this article. By dividing the trajectory extension model into two lower order models, the calculability of the disturbance invariant set of the tube-based MPC controller is ensured. Meanwhile, the bootstrap sampling method with a sliding window is used to estimate the range of the uncertainty online to reduce the conservativeness of the controller based on practical drilling data. Moreover, rules and a small interim deviation are introduced to adjust the parameters adaptively to decrease the curvature of the drilling trajectory and the calculation time. Simulations and hardware-in-the-loop experiment tests are carried out to illustrate the effectiveness of the control method. The results show that the proposed method completes the drilling task with a higher quality of trajectory and needs less time for calculation. [ABSTRACT FROM AUTHOR]