Feedback Linearizing Control of a Gas-Liquid Cylindrical Cyclone

Abstract

Compact separation technology is a smaller, lighter and low cost alternative to conventional separation technology. The technology is more suited for development and production of smaller and deeper oil and gas reservoirs and is therefore increasingly used by the oil and gas industry. Their small volume, which makes them desirable for subsea applications, also makes them very sensitive to ow variations, which in turn could result in operational problems and economic loss. The robustness against ow variations can be enhanced by improved control. In this paper, we propose a model-based nonlinear input-output feedback linearizing control algorithm to improve control. The design of the feedback linearizing control algorithm is based on feedback from the liquid level and gas pressure and includes complex internal dynamics. A proof of asymptotic output tracking of the controlled variables is provided for the closed loop feedback linearized system, including proofs of the behaviour of the complex internal dynamics. The control performance is compared to a PI feedback control algorithm in simulations and performs favourably.