摘要
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 wax deposit problem of crude oil pipelines scientifically, the effect of oil temperature, wall temperature and flow rate on wax deposition in single-phase crude oil was investigated by performing laboratory loop test which includes testing section and reference section. Then, the wax deposit laws of waxy crude oil were summarized systematically. The sediments were divided into 5 layers from the center of the pipe to the wall by special means. Based on microscopic observation, differential scanning calorimetry （DSC） and high temperature gas chromatography （HTGC）, the radial distribution differences of sediments were analyzed, including wax content, wax precipitation per temperature drop and carbon number distribution of sediments in different layers. It is shown that the closer to the pipe wall, the higher wax content of sediments and the greater mass fraction of molecules with high carbon number. And on the contrary, the closer to the conduit flow, the lower wax content of sediments and the smaller mass fraction of molecules with high carbon number. With the depositing of wax, the molecules whose carbon number is larger than the critical value diffuse to the pipe wall and precipitate, and the molecules whose carbon number is lower than the critical value diffuse back to the surface of sediment layers. The critical carbon number varies with oil product properties and deposit conditions. The research results are of practical significance for further study of wax deposition mechanisms so as to build up high-precision wax deposition prediction model.
作者
毕权
黄启玉
范开峰
BI Quan HUANG Qiyu FAN Kaifeng(China University of Petroleum （Beijing）/Beijing Key Laboratory of Urban Oil and Gas Distribution Technolog)
出处
《油气储运》
CAS
北大核心
2016年第9期952-957,共6页
Oil & Gas Storage and Transportation
基金
国家自然科学基金面上项目"油包水型乳状液蜡分子扩散和蜡晶颗粒沉积机理研究"
51374224
关键词
原油
蜡沉积
沉积物性质
含蜡量
时析蜡量
碳数分布
crude oil, wax deposit, sediment properties, wax content, wax precipitation per temperature drop, carbon number distribution
