Performance assessment of tripping and drilling operations controllers on an experimental drilling rig prototype

Abstract

Oil well drilling towers have different operating modes during a real operation, each mode involves certain external disturbances and uncertainties. Performance evaluation of robust or adaptive Cascade PID, Active Disturbance Rejection, Loop Shaping, Feedback Error Learning, and Sliding Mode torque controllers, during the tripping and drilling operations, and their practical comparison are studied and evaluated by constructing a drilling rig prototype. The modeling of the experimental setup is extracted by mathematical modeling, and system identification. The practical performance of the controllers and their stabilities against the uncertain forces including the parametric uncertainties and the external disturbances are studied during the operations, by loading and unloading a disturbance weight. It has been shown that the effects of uncertain forces are successfully eliminated by the controllers. The Loop Shaping controller has the best performance among all the designed controllers, and all of them roughly consume the same control energy. A desired speed profile is designed to shape the vertical speed reference during the tripping operation, then its effect on the system behavior is analyzed to prevent the slackening problem in the drilling cable. Also, the behavior of control architectures in two modes of autonomous drilling is studied and analyzed. By analyzing and optimizing the performance efficiency in a controlled environment, along with enhancing the performances of the controllers, what we learn in this research could presumably be applicable in the field to have an accurate and safe operation.