Identification Of Oil-Gas Mixed Transportation Process And Suppression Control Of Severe Slug Flow

The subsea oil and gas multi-phase transportation is the most common production process in the oil and gas field development and transportation process.In long distance multiphase pipeline,especially with lying pipe-standpipe system,severe slugging flow is often generated,and this harmful flow pattern will cause serious impact on transportation,downstream separation equipment and production.In this paper,the simulation model of oil and gas multiphase process is built by OLGA,a multiphase flow transient simulation software,in view of the problems of traditional PID control in suppressing severe slugging.Due to its complexity and specificity,a mathematical model of the controlled process with a high degree of fit is finally obtained by using the parametric model identification method.At the same time,considering the problem of more disturbances and uncertainties in the mixing process,the H∞ robust controller is designed to suppress the flow in the severe section.After verification under different working conditions and disturbance signals,the results show that the closed-loop control system composed of H∞ robust controller has good tracking and anti-disturbance performance,and can well suppress the influence of severe segment plug flow in the mixing process.Compared with PID control,the robust control system has faster regulation time and anti-disturbance capability,and the second-order controller model obtained by the reduced-order process has a simple structure and strong field implementability,which lays a good theoretical foundation for the next practical production application.