Abstract: Hydrate is easily generated in natural gas deep⁃water pipelines. It is of great significance to study the formation of influencing factors on the safe operation of pipelines. PVTsim was used to establish a numerical model, and based on five experimental data, the reliability of the model was analyzed. Using this model, the boundary conditions of natural gas hydrate formation under different gas composition and salinity conditions were simulated. At the same time, based on experimental data and OLGA simulation data, the quantitative relationship between hydrate volume fraction and molecular concentration of medium was obtained. The rusults show that hydrate formation is more affected by temperature than pressure. For natural gas, the addition of ethane, propane, carbon dioxide, and hydrogen sulfide all increases the range of hydrate formation, and the addition of nitrogen will reduce the range of hydrate formation. As the salinity in the water increases, the range of hydrate formation decreases. External temperature and pressure have little influence on the amount of hydrate formation and are almost negligible. Based on the research results of the hydrate slurry transportation technology, the critical methane mole fraction that ensures the safety of the HCFC⁃141b and THF hydrate slurry flow was obtained.

Key words: Hydrate, Hydrate slurry, Forming conditions, Generated amount, Influencing factors

摘要： 天然气深水集输管道内极易生成水合物，研究其形成影响因素对管道的安全运行具有重要意义。采用PVTsim建立了数值模型，并基于5种实验数据对模型进行了可靠性分析。利用该模型，模拟在不同工况下天然气形成水合物的边界条件，基于实验和OLGA模拟数据得到了水合物体积分数与介质摩尔分数的定量关系。研究表明，相比压力，水合物的形成受温度的影响更大。在天然气中，加入乙烷、丙烷、二氧化碳、硫化氢，均会使水合物形成范围扩大，而加入氮气，会使水合物形成范围缩小。随着水中盐度的增大，水合物生成范围缩小。外界温度、压力对水合物生成量的影响较小，几乎可忽略不计。基于水合物浆输送技术的研究成果，得到了保障HCFC⁃141b型和THF型水合物浆流动安全的临界甲烷摩尔分数。

关键词: 水合物, 水合物浆体, 形成条件, 生成量, 影响因素