Choking is a common method for controlling severe slugging in offshore oil and gas pipeline–riser systems. By combining experimental data with OLGA simulation, the influence of the installation position of the choke valve on control performance is analyzed. The results indicate that installing the valve near the riser top enables the elimination of slug flow at a larger valve opening, and can mitigate the pressure rise in the pipeline and facilitate valve selection for the slug control system, thus improving the safety and stability of the oil and gas transportation system. The mechanism analysis concludes that the principle for optimizing the valve installation position is to suppress liquid accumulation and liquid slug formation in the pipe section on an FPSO unit and to promote gas outflow. In a practical offshore pipeline case, the results under low-liquid-production-rate conditions are consistent with the simulated trends of the laboratory pipeline. However, in the case of the biggest production rate, the control performance at different installation positions tends to converge. The findings of this study can provide a reference for designing slug control strategies on offshore oil and gas production platforms.
Chen et al. (Fri,) studied this question.