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高凝原油管道输送蜡沉积规律实验研究 总被引:1,自引:0,他引:1
针对高凝原油在管道输送过程中管壁结蜡等问题,通过室内建立的小型管流结蜡环道实验装置,模拟输油管道运行中某一管段的蜡沉积情况,研究了含蜡原油的蜡沉积速度,考察了蜡的沉积规律受温度的影响。通过计算,确定了实验条件下的结蜡量,并利用差热扫描量热仪从微观角度分析测试了蜡沉积物的特性,进而探讨了结蜡机理和影响管壁结蜡的因素。 相似文献
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流花16-2油田海底管道原油在深水不保温输送过程中,管壁结蜡对管道全线总传热系数的变化影响很大。本文通过室内环道蜡沉积实验建立流花16-2油田管道蜡沉积预测模型,模拟研究了不同沉积时间条件下管道沿线结蜡速率及结蜡厚度的变化,并引入单位时间管道全线总结蜡量概念对管道全线结蜡速率进行了描述。结果表明,在管壁结蜡层的保温作用下,管道沿线最大蜡层厚度位置处的总传热系数迅速降低导致后管段油流温度升高,管道沿线蜡沉积速率峰值向管段末端移动;随着沉积时间的增长,管道全线结蜡区域逐渐扩大,导致单位时间管道全线总结蜡量增大;根据管道沿线最大蜡层厚度2 mm或管道全线总结蜡量10 m^3的沉积时间,推荐流花16-2海底管道清管周期为3~5 d,以保障海底管道的安全运行。 相似文献
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原油管道输送防蜡减阻效果的实验室评价方法 总被引:2,自引:0,他引:2
随着人们对原油减阻防蜡研究的深入,实验室评价装置和性能测试方法也将进一步得到完善和发展。本文对原油输送管道内壁涂层和添加剂的减阻、降粘、防蜡效果的实验室评价装置及实验方法作了总结,对涂层物理化学性质的评价方法及管壁涂层的防蜡减阻机理进行了讨论。 相似文献
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原油输送管道经过一定时间的使用,由于原油中粘性分子在管壁的沉积,造成实际输油管径减少,压降增大,大大增强了系统能耗。通过分析原油输送管道结蜡情况得出结论:采用机械清管方法可以清除管内结蜡,保证管路正常输送。在阐述机械清管的工艺设计、器具选择和操作规程的基础上,进一步对器具的维护和清管中的注意事项进行简要说明。 相似文献
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大庆原油管输结蜡规律与清管周期的确定 总被引:2,自引:0,他引:2
在确定不同流态区管壁处剪切应力、蜡晶溶解度系数、径向温度梯度及管道沿线温降分布的基础上,回归建立了适用于描述大庆油田某两联合站间输油管道蜡沉积的结蜡模型。根据差压法原理,建立了研究原油管输结蜡过程室内模拟试验装置,并覆盖该输油管道的典型工况条件开展了管输原油结蜡模拟试验。相对偏差分析表明,结蜡模型预测结果与试验值的适配性良好。进而在预测运行时间对该输油管道结蜡影响的基础上,结合结蜡层厚度对管道轴向温降及压降的作用,确定了年季节最高与最低土壤温度期的清管作业周期分别为4个月和3个月。 相似文献
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Paraffin deposition is a severe global problem during crude oil production and transportation. To inhibit the formation of paraffin deposits, the commonly used methods are mechanical cleaning, coating the pipe to provide a smooth surface and reduce paraffin adhesion, electric heating, ultrasonic and microbial treatments, the use of paraffin inhibitors, etc. Pipeline coatings not only have the advantages of simple preparation and broad applications, but also maintain a long-term efficient and stable effect. In recent years, important progress has been made in research on pipe coatings for mitigating and preventing paraffin deposition. Several novel superhydrophilic organogel coatings with low surface energy were successfully prepared by bionic design. This paper reviews different types of coatings for inhibiting wax deposition in the petroleum industry. The research prospects and directions of this rapidly developing field are also briefly discussed. 相似文献
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Wax deposits on the wall of a crude oil pipeline are a solid wax network of fine crystals, filled with oil, resin, asphaltene and other impurities. In this paper, a series of experiments on wax deposition in a laboratory flow loop were performed under different conditions (flow rate, temperature differential between crude oil and pipeline wall, and dissolved wax concentration gradient), and the wax deposits were analyzed, so quantitative relationships among wax content, wax appearance temperature (WAT), shear stress, and radial concentration gradient of dissolved wax at the solid/liquid interface were obtained. Finally, a model was established to predict WAT and the wax content of the deposit. 相似文献
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在结蜡油井中使用固体化学防蜡剂,可有效抑制油井管、杆、泵等处结蜡,延长有杆泵的检泵周期,降低抽油机能耗。用动态结蜡率测试仪及流变仪分别测试防蜡率及析蜡点的变化,评价防蜡剂在室内的应用效果。通过室内理论计算检泵周期、溶解速度、防蜡率之间的关系,预测了防蜡剂在井底的有效性。用抽油机系统效率测试仪,测试抽油机电机运行的电能参数及安装在抽油机悬绳器上的传感器的油井载荷,对比结蜡井措施前后的数据,评价防蜡效果。测试表明,结蜡井使用化学固体防蜡剂可使油井载负荷平均下降9.73kN,系统效率提高6.92%,综合节电率22.23%。 相似文献
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Zhen Hao Lim Hikmat Said Al Salim Norida Ridzuan Ronald Nguele Kyuro Sasaki 《石油科学(英文版)》2018,15(3):577-590
The present study investigated the wax deposition tendencies of a light Malaysian crude oil(42.4° API), and the wax inhibiting potential of some surfactants and their blends with nanoparticles. With the knowledge that the majority of the wax inhibition research revolved around polymeric wax inhibitors, which cause environmental issues, we highlighted the potential of surfactants and their blend with SiO_2 nanoparticles as wax deposition inhibitors. Different surfactants including oil-based, silane-based, Gemini and bio-surfactants were considered as primary surfactants. The primary surfactants and their respective blends at a concentration of 400 ppm were screened as wax inhibitor candidates using cold finger apparatus. The screening results showed a significant influence on the paraffin inhibition efficiency on wax deposition by using 400 ppm of silane-based surfactant, which decreased the wax deposition up to 53.9% as compared to that of the untreated crude oil. The inhibition efficiency among the silane-based surfactant(highest) and bio-surfactant(lowest)revealed an appreciable difference up to 36.5%. Furthermore, the wax from the treated sample was found to deposit in a thin gel-like form, which adhered inadequately to the surface of the cold finger. A further investigation by blending the 400 ppm silane-based surfactant with a 400 ppm SiO_2 nanoparticle suspension in a load ratio of 3:1 found that the wax inhibition decreased up to 81% as compared to the scenario when they were not added. However, we have shown that the synergy between the silane-based surfactant and the nanoparticles is influenced by the concentration and load ratio of surfactant and nanoparticles, residence time, differential temperature and rotation rate. 相似文献
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大庆原油蜡沉积规律研究 总被引:15,自引:5,他引:10
在理论分析及室内试验的基础上,系统研究了油温、流速、管壁处温度梯度等参数对大庆原油蜡沉积的影响.在原油与管壁温差相同时,不同温度段蜡沉积速率并不相同,存在蜡沉积高峰区.在壁温相同时,随油温升高,蜡沉积速率逐渐增加.在油温、壁温相同的条件下,随流速增加,蜡沉积速率下降.建立了大庆原油蜡沉积模型,并利用该模型预测了铁岭-秦皇岛输油管线不同季节、不同时间沿线蜡沉积分布.铁-秦线冬季存在蜡沉积高峰区;春、秋季出站时蜡沉积最严重,下一站进站时蜡沉积最轻;夏季蜡沉积速率更小,且沿线变化不大. 相似文献
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采用Couette蜡沉积实验装置研究了聚乙烯醋酸乙烯酯(EVA)型防蜡剂对长庆原油蜡沉积特性的影响,分析了不同管输温度条件下EVA型防蜡剂的防蜡效果。研究发现,与空白原油相比,加剂原油的蜡沉积速率大幅降低,同时蜡沉积物的老化速率升高。无论是在恒定油壁温差还是在恒定壁温条件下,EVA型防蜡剂的防蜡效率均随油温的升高而不断降低,EVA对蜡沉积物老化速率的提升幅度均随油温的升高而不断增大。通过分析EVA型防蜡剂对长庆原油流动特性、低温胶凝结构特性及微观蜡晶形貌的影响,阐明了EVA型防蜡剂对长庆原油蜡沉积特性的影响机理,并从蜡沉积物初始凝油层抗剪切强度及蜡分子扩散速率2个角度揭示了管输温度对EVA型防蜡剂防蜡效果的影响。 相似文献
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普适性结蜡模型研究 总被引:14,自引:3,他引:11
根据原油在管道内流动特性及析蜡规律,提出了有效析蜡量的计算方法.利用F检验法筛选了原油结蜡的主要影响因素,包括原油黏度、管壁处剪切应力、温度梯度及管壁处蜡晶溶解度系数.利用9种原油室内环道结蜡实验数据,按照逐步线性回归的方法,得到了含蜡原油的普适性结蜡模型.该模型不需进行结蜡模拟实验,只需根据原油的黏度、析蜡特性及密度等物性参数就可预测原油的结蜡规律.在未进行室内结蜡模拟实验的情况下,利用普适性结蜡模型预测了中宁-银川输油管道不同工况下沿线结蜡分布,并和现场运行参数进行了对比,平均误差为6.32%,最大误差为20%,预测结果为现场清管作业提供了依据. 相似文献