Abstract Gas hydrates can readily form in deep-water oil and gas production processes and can lead to disruptions in flow conditions. In this work, in order to investigate the interdependence of hydrate formation and multiphase flow characteristics, a transparent rock-flow cell was used where a series of hydrate formation and flow experiments were conducted under different rocking conditions, which corresponded to different flow regimes. Based on the experimental phenomena, stratified gas-liquid flow pattern, two kinds of emulsions, and three kinds of liquid-liquid flow patterns were identified under different rocking conditions before hydrate formation. Upon hydrate formation onset, phase separation of the liquid phases could be only clearly observed for W/O emulsions. In this work, hydrates mainly formed in the bulk liquid and gradually deposited on the pipe wall by particle-wall adhesion and accumulated on the two ends of the pipe under flow conditions. In addition, for small rocking angles, hydrate chunks formed by agglomeration and hydrate bedding at the bottom of the pipe could be observed. For all the experiments, no free water could be observed at the end of the test. Moreover, the water conversion for each rocking condition was calculated according to the gas consumption. This work provides further insight how flow conditions affect hydrate formation and vice-versa.

中文翻译：

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气体水合物形成与多相流动条件之间耦合的表征

摘要 天然气水合物很容易在深水油气生产过程中形成，并可能导致流动条件中断。在这项工作中，为了研究水合物形成和多相流特征的相互依赖性，使用透明的岩石流动池，在不同的摇摆条件下进行了一系列水合物形成和流动实验，这对应于不同的流态。根据实验现象，确定了水合物形成前不同摇摆条件下的分层气液流型、两种乳状液和三种液液流型。在水合物形成开始时，只有 W/O 乳液才能清楚地观察到液相的相分离。在这项工作中，水合物主要在本体液体中形成，并通过颗粒壁粘附作用逐渐沉积在管壁上，并在流动条件下聚集在管的两端。此外，对于小摇摆角，在管道底部可以观察到由团聚和水合物层理形成的水合物块。对于所有实验，在测试结束时均未观察到游离水。此外，根据耗气量计算每个摇摆条件下的水转化率。这项工作提供了进一步的见解，即流动条件如何影响水合物的形成，反之亦然。对于所有实验，在测试结束时均未观察到游离水。此外，根据耗气量计算每个摇摆条件下的水转化率。这项工作提供了进一步的见解，即流动条件如何影响水合物的形成，反之亦然。对于所有实验，在测试结束时均未观察到游离水。此外，根据耗气量计算每个摇摆条件下的水转化率。这项工作提供了进一步的见解，即流动条件如何影响水合物的形成，反之亦然。