A major flow assurance concern is to mitigate the safety risks associated with hydrate plug formation and to provide cost effective flow assurance strategies for mature fields by extending subsea tiebacks. One major challenge for the flow assurance community is the fundamental understanding of the hydrate formation and plugging under different multiphase flow conditions. Such understanding will only lead to better hydrate management guidelines to effectively mitigate the safety risks associated with hydrates, but could also potentially reduce the operating costs by providing improved inhibitor injection strategies. The manner in which the hydrates interact/interfere with multiphase flow can be significantly different for water continuous, oil continuous, and partially dispersed systems. The latter is defined as a system containing oil/gas/water, where the water is present both as free water and partially dispersed in the oil phase (e.g., entrained water in the oil). Efforts were made to study the interaction between hydrates and multiphase flow. Controlled amounts of hydrates were formed and their effect on the pump pressure drop was studied systematically. This paper presents the experimental results and analyses of these experiments. Lessons resulting from this work could provide valuable insight with regard to the behavior of hydrates in multiphase flow, and hence could help improve operating company production strategies to mitigate the risks associated with hydrate plugs in complex multiphase systems.

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