The State-of-the-Art of Gas-Liquid Compact Separator Control Technology: From Lab to Field

Conventional gas-liquid separators are vessel-type with simple level, and pressure control since the residence time is large. Compact gas-liquid separators, such as Gas-Liquid Cylindrical Cyclone (GLCC^©), have emerged recently as alternatives to reduce size and increase separation efficiency for offshore and subsea applications. As compared to the vessel-type separators, compact separators, are simple, low-cost, low-weight, require little maintenance and are easy to install and operate. However, the residence time of the GLCC is very small. Consequently, it can get upset easily due to high flow variations at the inlet, for example, slugging, without the aid of fast and accurate control systems. In the past, lack of understanding of control system dynamics and design tools have prevented this technology from fast field deployment. The objective of this study is to present a review of the compact gas-liquid separator (GLCC) control technology. This includes the development of control strategies, control system design, dynamic simulation, experimental investigation and field applications. The performance of compact gas-liquid separator (GLCC) strongly depends on the liquid level and/or separating pressure. In this investigation, several control strategies have been developed for field applications of gas-liquid compact separators. Especially, an optimal control strategy was developed for handling slug flow and optimizing the system performance in terms of reduced or eliminated liquid carry-over (LCO) or gas carry-under (GCU). The developed strategies have been used for the design of several GLCC applications, currently in operation in the field. Details of these applications are also presented. This study provides the state-of-the-art of gas-liquid compact separator control technology from the lab to field.