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Clarifying the interaction effect between hydrate and wax is of great significance to guarantee operation safety in deep water petroleum fields. Experiments in a high-pressure hydrate slurry rheological measurement system were carried out to investigate hydrate formation and slurry viscosity in the presence of wax crystals. Results indicate that the presence of wax crystals can prolong hydrate nucleation induction time, and its influence on hydrate growth depends on multiple factors. Higher stirring rate can obviously promote hydrate growth rate, while its influence on hydrate nucleation induction time is complicated. Higher initial pressure will promote hydrate formation. Gas hydrate slurry shows a shearthinning behavior, and slurry viscosity increases with the increase of wax content and initial pressure. A semiempirical viscosity model showing a well-fitting is established for hydrate slurry with wax crystals by considering the aggregation and breakage of hydrate particles, wax crystals, and water droplets.

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As oil and/or gas exploration and production enter deeper water, the flow assurance confronts challenges, one of which is the hydrate formation and blockage. Investigations about gas hydrate formation and hydrate slurry flow in a multiphase transportation system were performed on a newly constructed high-pressure experimental loop. On the basis of the experimental hydrate formation data, an inward and outward hydrate shell model was improved to predict the gas consumed amount during the hydrate formation process. With the help of a focused beam reflectance measurement and particle video microscope installed in this flow loop, the distribution of hydrate particles was observed, characterized in the coalescence and fragmentation. A “minimum safety flow rate” was first addressed for the safety of hydrate slurry flow in a multiphase transportation system. Then, the comparisons between our experimental data of the natural gas hydrate slurry flow pattern and the Mandhane flow pattern map revealed the influence of hydrate particles on the flow pattern of the slurry. Furthermore, the influence of the gas/liquid superficial velocity on the pressure drop was discussed at stratified flow for this gas hydrate slurry multiphase system.