摘要：AbstractDirectional drilling techniques, based on rotary steerable systems, are used to generate complex curved boreholes. In practice, however, boreholes drilled with such systems often show instability-induced borehole spiraling, which negatively affects the borehole quality and increases drag losses while drilling. As a basis for controller synthesis, we present a directional drilling model in terms of delay differential equations characterizing the evolution of the borehole inclination. Next, the problem of curved well-bore generation is formulated as a tracking problem and an output-feedback control strategy is developed, solving this tracking problem while guaranteeing the prevention of borehole spiraling.
