天然气水合物浆在管道中的流动沉积特性

随着海底天然气水合物开采及开发技术研究的不断发展,水合物浆的宏观流动特性研究成为保证天然气水合物浆顺利输送的必要条件。为此,对天然气水合物浆液在管道中的稳定流动状态及临界堵塞条件进行了研究,以传统的固液双层流动模型为基础,结合天然气水合物在水平管道中的流动特点,提出了天然气水合物浆稳定流动的判定标准——临界流动速度和临界床层高度,即管道内出现固定床层的临界速度和该速度对应的床层高度;并提出了计算天然气水合物浆流型及流动参数的方法。在此基础上,对天然气水合物浆在管道中流动的沉积特性进行了研究,设计正交方案,对比了不同因素对临界沉积速度的影响因子。实验验证结果表明:该方法可以较为准确地描述天然气水合物浆的流动状态及其特征参数,对判断其安全流动具有一定的指导意义。

Flow and deposition characteristics of natural gas hydrate in pipelines

Along with the increasing demand for marine hydrate recovery and exploitation from the sea floor, the study of hydrate slurry flow characteristics serves as a robust technical support for the steady operation of undersea multiphase flow pipelines. Thus, focusing on the steady flow characteristics of hydrate slurry and critical parameters of hydrate plugging, this study presented a new model for hydrate slurry flow pattern and flow parameters prediction based on the traditional solid liquid two layer flow model. According to the flow characteristics of hydrate slurry in horizontal pipelines, the criterion for judging the steady flow of hydrate slurry was determined, i. e., the critical flow velocity and critical bed height in pipelines. Then the deposition characteristic was further studied and orthogonal experiments were carried out to determine the influence factors of different parameters on critical plug velocity. In the end, experimental results verified that the new model gives relatively accurate prediction of flow patterns and parameters, which can help to judge the flow assurance of natural gas hydrate in pipelines.