Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2018-02-01 Cooperative journals: 《工程热物理学报》
Abstract: Severe slugging is undesired in offshore pipeline-riser system and riser topside choking is an effective method for the elimination of severe slugging. Flow patterns and transitions induced by riser topside choking on severe slugging were studied experimentally. It is found that the pressure drop across the choke increases with the decrease of the valve opening. The pressure of the gas trapped in the pipeline is counteracted and therefore the expansion of the gas is suppressed. As a result, the gas penetrates into the riser in the form of individual bubbles, leading to the formation of slug flow and bubbly flow. The stability boundary accounting for the prediction of the behavior of gas-liquid flow in a pipeline-riser system in the process of riser topside choking is also proposed. The predictions are tested against experimental results, showing a reasonable agreement.