An analysis of flow improver effects on interfacial characteristics in horizontal slug flow conditions

摘要

A semi-empirical model was developed to evaluate the effect of flow improver on the interfacial friction factor, interfacial pressure drop and the ratio of the gas and interfacial friction factors (f{sub}i/f{sub}g). Experiments were performed in a 10.16 cm diameter, 40 m long multiphase flow loop. Light LVT 2.5 cP oil was used as the liquid phase with carbon dioxide gas. A commercial flow improver was used which has long chain polymer characteristics. Flow improver concentrations ranged from 0 to 50 ppm based on total fluid volume within the system. Analysis showed that at a constant superficial liquid velocity with 0 ppm of flow improver, the ratio of f{sub}i/f{sub}g increased with an increase in the superficial gas velocities. The ratio decreased with the addition of flow improver for all conditions. At superficial gas and liquid velocities of 8 and 0.5 m/s, the ratio of f{sub}i/f{sub}g decreased by a maximum factor of 63% as the flow improver concentration was increased from 0 to 50 ppm. The flow improver was able to reduce the turbulence at the gas-liquid interface, which led to a decrease in the interfacial pressure drop and friction factor. It was noticed that the interfacial friction factor reduced by a maximum factor of 57% with the addition of flow improver. The effectiveness of the interfacial pressure drop component reached values as high as 72% at superficial gas and liquid velocities of 8 and 1 m/s with 50 ppm of flow improver. The model provides a quantitative understanding of flow improver effects on interfacial characteristics in slug flow conditions.