Severe slugging may occur at low flow rate conditions when a downward inclined pipeline is followed by a vertical riser. This phenomenon is undesirable for offshore oil and gas production due to large pressure and flow rate fluctuations. It is of great technological relevance to develop reliable and economical means of severe slugging mitigation. This study aims to develop an automated control system to detect and mitigate the formation of severe slugging through a choke valve and a series of sensors. As a first step, an overall flow map is generated to indicate the region within which severe slugging may occur based on Boe’s criterion [1] and Taitel’s model [2, 3]. It was possible to obtain different flow patterns by controlling the rate of water and gas injection.

The aim of this paper is, however, the formation of severe slugs and study of mitigation techniques. In the control part, we used a choke valve controlled by software which is in feedback with data from a system with pressure, temperature, flow, which are able to measure even small changes in the relevant parameters to the model. A two-phase flow loop was built for the study of severe slugging in pipeline-riser system with air and water as work fluids. The inner diameter of riser and flowline is 76.2 mm. The riser is 20 meters high and the flowline is 15 meters long and could be inclined upward or downward up to 8-degree. It has been shown by experiments how riser slugging can be controlled by automated control system.

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