Slugging is an undesirable flow pattern with liquid blockages that can occur in multiphase flow lines transporting both gas and oil in the same pipeline. The challenge of handling slug flow becomes more important with the recent development, where the number of satellite fields increases utilizing the existing production platforms offshore. The work in this paper concerns suppression of slug flow in multiphase pipelines by active use of the topside choke in a feedback control loop, based on process measurements such as pressure and density. Conventional PID controllers are used, and the slug control system can therefore easily be fully integrated in the existing topside distributed control system at offshore installations. There are three main contributions in this paper: the use of density measurements along with pressure measurements in a cascade feedback PID controller to suppress both severe and moderate slugging, the field experience with this controller from the Statoil operated Heidrun field and the experimental results from Sintef Petroleum Research Multiphase Flow Laboratory.
展开▼
