Parameter and delay-dependent sliding mode recoil control for deepwater drilling risers

Abstract

This study deals with a parameter and delay-dependent sliding mode control strategy to mitigate recoil responses of drilling risers. First, by taking into consideration the nonlinear top tension of the tensioner, external heave motion of platform, friction resistance of drilling discharge, and unmodeled dynamics, a nonlinear recoil dynamic model of the drilling riser is established. Then, by introducing parameters and time-delays into control channel, a parameter and delay-dependent sliding mode recoil controller is developed to attenuate recoil movements of the riser. The existence conditions of the sliding mode recoil controller with parameters and time-delays of the riser are derived. Simulation results demonstrate that the designed sliding mode recoil controllers can reduce the recoil responses of the riser remarkably, and outperform some existing recoil controllers. Moreover, it is found that the parameter and delay-dependent sliding mode recoil control scheme can provide more options to design recoil controllers for the drilling riser.