Experimental Investigation of Downhole Vortex Gas Separator Efficiency Under Two-Phase Flow Conditions: Impact of Differential Pressure and Flow Rates

Abstract This study evaluates the performance of a downhole Vortex Gas Separator (VGS) under two-phase flow conditions, focusing on gas and liquid separation efficiencies. A series of 120 experiments were conducted with nitrogen and water mixtures at flow rates ranging from 500 to 4000 barrels per day (bpd). The impact of differential pressure between gas and liquid outlets on separation efficiency was examined, with optimal performance observed at 50% gas volume fraction (GVF). These findings provide valuable insights for optimizing the design and operation of VGS systems in gassy wells. A flow loop incorporating a vertical 7-ft steel casing and a 2.6-ft VGS assembly was used to assess performance under varying flow conditions. Data acquisition with LabVIEW included monitoring flow rates, differential pressure, and liquid levels. Results revealed that low gas outlet pressure enhanced gas separation but caused instability due to liquid carryover, while high gas outlet pressure improved liquid separation at the expense of gas efficiency. Peak separation efficiencies exceeding 80% were achieved at 2500–3000 bpd. The study underscores the critical role of maintaining stable differential pressure and liquid levels, offering practical guidance for optimizing downhole separator performance and informing future design advancements.