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Abstract The high pressure and low temperature operational conditions of deepwater subsea facilities often result in the formation of gas hydrates, which is one of the most challenging flow assurance issues. The variant water cuts and flowline geometries could result in complicated flow patterns leading to different hydrate formation mechanisms. In previous work, we have developed hydrate formation models both for oil- and water-dominated systems. The model for oil-dominated systems considers the water phase being dispersed as droplets in an oil continuous layer, and uses either a kinetics or a transport model to calculate hydrate formation at the interface of water droplets. On the other hand, water-dominated systems contain small amounts of oil, and a mass transfer-based hydrate growth model is used. This paper presents a new transient hydrate formation model that predicts hydrate growth and transportability in oil- and water-dominated environments, which might be present simultaneously in oil and gas pipelines due to changes in fluid distribution in complex multiphase flow systems. Simulations of high-pressure pilot-scale flowloop experiments at different water cuts are used to verify this modeling approach. Furthermore, the proposed hydrate simulation tool is applied to analyze the flow dynamics of a subsea tieback involving hydrate formation at varying water cuts after flowloop verification. This simulation model is targeted to be widely used to simulate oil-dominated pipelines, as well as high water cut systems leading to phase inversions, and represents a step further towards the development of more comprehensive hydrate formation models. Graphical abstract Image 1 Highlights • Hydrates can form simultaneously in oil- and water-dominated sections of a pipeline. • Hydrate formation can trigger dispersion inversion from water to oil-continuous. • Inclination of pipeline affects hydrate accumulation in pipelines. • Proposed hydrate formation model is validated through flowloop simulations. • The validated model is applied to field simulations at high water cuts. [ABSTRACT FROM AUTHOR]

The article discusses research which was done to show what actually happens with the human body to make a high jump takeoff happen. The findings show that in order for a high jump takeoff to happen there has to be a cooperative effort between muscles in the arms, the right leg and foot which is used for landing in the jump.