乙烯-醋酸乙烯酯共聚物对含蜡原油降凝效果评价  

Depressive effects evaluation of ethylene-vinyl acetate copolymer on waxy crude oils

作　　者：杨飞[1] 李传宪[1] 林名桢[1] 

机构地区：[1]中国石油大学储运与建筑工程学院,山东东营257061

出　　处：《中国石油大学学报（自然科学版）》2009年第5期108-113,共6页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家'863'高技术研究发展计划项目(2006AA09Z302)

摘　　要：以长庆、青海含蜡原油为研究对象,考察乙烯-醋酸乙烯酯共聚物(简称EVA)降凝剂对含蜡原油的降凝效果。利用DSC热分析仪和偏光显微镜考察加剂前后含蜡原油的结晶特性和原油中的蜡晶形貌,并通过凝点和流变试验评价EVA降凝剂对含蜡原油的降凝效果。结果表明:随着分子量的增大,EVA结晶性能稍有提高;随着极性基团含量的提高,EVA结晶性能显著恶化。EVA降凝剂对含蜡原油的降凝效果与原油组成和降凝剂结构有关:随着原油中蜡含量的增大或蜡平均碳数的提高,降凝剂的降凝效果变差;降凝剂的分子量通过影响其在原油中的溶解性来影响降凝效果;EVA极性基团含量过高(大于33%)或过低(小于18%)都不利于降凝,只有在中间范围内时(28%左右),才能起到较好的降凝效果;随着EVA浓度的提高,改性效果先不断提高,然后在高浓度下基本保持不变。Using Changqing and Qinghai waxy crude oils as research objects, the depressive effects of ethylene-vinyl acetate （EVA） copolymer pour point depressant on the waxy crude oils were studied. The crystallization abilities of waxy crude oils were investigated by differential scanning calorimeter （DSC） and the morphology of wax crystals in the waxy crude oils doped/ undoped with EVA was observed through a polarized light microscope. Meanwhile, the depressive effects of EVA on waxy crude oils were evaluated through pour point tests and rheological experiments. The results show that the crystallization ability of EVA improved slightly by increasing the molecular weight of EVA but deteriorated greatly by increasing the VA content. The depressive effects of EVA on waxy crude oils were related not only to the crude oil composition but also to the molecular structure of EVA. With the increase of wax content in crude oils or the average carbon number of waxes, the depressive effects of EVA deteriorated greatly, the molecular weight of EVA affected its depressive effects by controlling the solubility of EVA in waxy crude oils. The depressive effects of EVA were good at the VA content around 28%, when the VA content was too high （ 〉33% ） or too low （ 〈 18% ）, however, the depressive effects were poor. The depressive effects of EVA first improved with EVA concen- tration increasing and then kept nearly unchanged at high EVA concentrations.

关 键 词：乙烯-醋酸乙烯酯共聚物 降凝剂 结晶性能 蜡晶形态 降凝效果 

分 类 号：TE624.8[石油与天然气工程—油气加工工程]