Gas injection at riser base solves slugging flow problems

Abstract

This paper discusses test-rig studies and operating experience which have shown that riser-base gas injection can help prevent severe slugging and smoother start-up transients in subsea pipelines. The studies were based on predictions that multiphase lines proposed as part of the forties field extension would be subject to severe slugging. Test-rig studies were undertaken to analyze severe slugging and to demonstrate gas injection as a means of prevention. Following scale-up studies, riser-base gas injection systems were installed on both 12-in. production and 6-in. test lines. Comprehensive instrumentation was also put onto the lines.