Abstract
The scope of the present work was to develop a dynamic control methodology to reject disturbance (lost circulation) during the drilling of oil wells. A scheme of control structure reconfiguration (feedback-feedfoward) to control annulus bottom-hole pressure through choke valve manipulation was implemented. The dynamic behavior of the drilling unit and the disturbance (lost circulation) were modeled through Sundaresan & Krishnaswamy (1977) method. The PI (proportional-integral) controller parameters were calculated through Ziegler-Nichols (1942) and Cohen-Coon (1953) methods, being performed fine-tuning of the parameters. The feedfoward controller parameters were estimated using the open loop response for load and manipulated disturbances, as pointed out by Seborg et al (2011).