This paper reports the effect of inlet choking and addition of surfactant on the performance of a parallel pipe oil–water separator. These two issues can have a strong effect on oil–water separation in real hydrocarbon production systems.
Experiments were performed with Exxsoltextsc {TM} D60 and salt water. Three choke settings were tested for flow rates in the range 300–500 L/min, with three inlet water cuts and three water extraction rates. The test matrix was run with and without added surfactant. The oil–water distribution and behaviour within the separator is also studied. Droplet size measurements were performed at the separator inlet for droplet size distribution generation in the form of cumulative volume plots.
The study shows that inlet choking has an overall negative effect on separator performance, especially for water-continuous inlet regimes. The maximum decrease in performance due to choking was 14 pp, while it was 4 pp due to addition of surfactant.