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为了科学解决原油管道的蜡沉积问题,使用设有测试段和参比段的室内环道试验研究了油温、壁温、流速等因素对单相原油蜡沉积过程的影响,系统总结了含蜡原油蜡沉积规律。通过特殊手段将沉积物从管中心至管壁分为5层,运用显微观察、差示扫描量热仪法及高温气相色谱法,分析了沉积物性质的径向分布差异,包括不同层位沉积物的含蜡量、时析蜡量及碳数分布的差异。结果表明:越靠近管壁,沉积物的含蜡量越大,其大碳数分子的质量分数越大;相反,越靠近管流的沉积物,其含蜡量越小,大碳数分子的质量分数越小。大于临界碳数的分子随着蜡沉积的进行会向管壁扩散并析出,小于临界碳数的分子则向沉积层表面反扩散,临界碳数随油品性质及沉积条件的不同而不同。研究结果对于深入研究蜡沉积机理,进而建立更加精确的蜡沉积预测模型具有一定的指导意义。
In order to solve the problem of wax deposition in crude oil pipeline scientifically, the influence of oil temperature, wall temperature and flow rate on the deposition of single-phase crude wax was studied by using indoor loop test with test section and reference section. Crude oil wax deposition law. The sediment was divided into five layers from the tube center to the tube wall by special means. The microscopic observation, differential scanning calorimetry and high temperature gas chromatography were used to analyze the radial distribution differences of sediment properties, including different horizon Sediment wax content, the amount of wax analysis and carbon number distribution differences. The results show that the closer the tube wall, the greater the wax content of the sediments is, the larger the mass fraction of large carbon molecules is. On the contrary, the closer the sediments are, the smaller the wax content is. The smaller the mass fraction Molecules that are larger than the critical carbon number will diffuse and precipitate into the tube wall as the wax deposition progresses, while molecules smaller than the critical carbon number will reversely diffuse to the surface of the deposited layer. The critical carbon number will vary with the nature of the oil product and the deposition conditions. The results of this study are of guiding significance for the further study of the wax deposition mechanism and the establishment of a more accurate wax deposition prediction model.