Application of Model -Free Adaptive Control in Managed Pressure Drilling

摘要

Aiming at the characteristics of large lag, strong interference, nonlinearity and difficult pressure control in pressure controlled drilling, this paper designs an automatic control system for pressure controlled drilling without model adaptive control. The automatic control system consists of signal input device, pressure controlled drilling electronic control unit, actuator and other devices. In order to improve the speed and stability of pressure control in pressure drilling, a model-free adaptive control scheme is proposed. The control scheme only needs on-line I/O data of the controlled system to complete the design of the controller, which has strong resistance to nonlinearity and is suitable for more complicated control projects. The system is modeled and simulated in MATLAB. The experimental results show that compared with cascade PID control, the pressure regulating time of the automatic control system of pressure controlled drilling using model-free adaptive control scheme is shorter and the pressure change curve is smoother, which can better meet the control requirements of the automatic control system of pressure controlled drilling.