2009年6月JOURNALOFPETROCHEMICALUNIVERSITIESJun.2009文章编号:1006-396X(2009)02-0020-06聚丙烯酸酯降凝剂对含蜡原油降凝规律的研究飞1,李传宪13,林名桢1,李志岩2,涛1杨于(1.中国石油大学(华东)储运与建筑工程学院,山东东营257061;2.中油辽河工程有限公司,辽宁盘锦124000)摘要:采用DSC热分析仪研究了聚丙烯酸酯(PA)降凝剂的结晶性能及加剂前后含蜡原油的结晶特性,通过偏光显微镜观察了加剂前后原油中蜡晶形貌,并通过凝点试验和流变实验评价了PA降凝剂对长庆、青海两种含蜡原油的降凝效果。结果表明,PA降凝剂的结晶性能随烷基侧链碳数的增长显著提高,但不受降凝剂平均相对分子质量的影响。添加PA降凝剂能够抑制原油中蜡晶的析出、降低原油析蜡点,并且使原油中蜡晶尺寸变大,结构变紧凑,从而能够释放更多的液态油分,改善含蜡原油的低温流变性。PA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,原油中蜡含量越高、高碳数石蜡所占比例越大,降凝剂的降凝效果越差;随着降凝剂平均相对分子质量的提高,PA分子在原油中的溶解性变差,卷曲程度提高,导致PA与石蜡间作用力减弱,降凝效果变差;PA烷基侧链碳数与原油中石蜡碳数越匹配,降凝剂分子与石蜡的作用越强,降凝效果也越理想。关键词:聚丙烯酸酯;降凝剂;结晶性能;蜡晶形貌;降凝效果中图分类号:TE624.8文献标识码:ADepressiveEffectofPolyacrylate(PA)PourPointDepressantonWaxyCrudeOilsYANGFei1,LIChuan-xian13,LINMing-zhen1,LIZhi-yan2,YUTao1Abstract:Usingdifferentialscanningcalorimeter(DSC),thecrystallizationabilitiesofpolyacrylate(PA)pourpointdepressantandwaxycrudeoilsdoped/undopedwithPAwerestudied;thenthemorphologyofwaxcrystalsinthewaxycrudeoilsdoped/undopedwithPAwasinvestigatedthroughapolarizedlightmicroscopeandthedepressiveeffectofPAonChangqingandQinghaiwaxycrudeoilswasevaluatedbythepourpointtestsandrheologicalexperiments.TheresultsshowthatthecrystallizationabilityofPAimprovedgreatlybyincreasingthealkylsidechainlengthofPAbutkeptunchangedwiththeincreaseofaveragemolecularweightofPA.TheadditionofPAcaninhibitthewaxprecipitationanddecreasethewaxappearancetemperatureofwaxycrudeoils.ThesizeofwaxcrystalsbecomelargerandthestructureofthembecomecompactafterPAaddition,leadingtothegreatimprovementofthelowtemperaturerheologyofwaxycrudeoils.ThedepressiveeffectofPAonwaxycrudeoilsarerelatedtothecrudeoilcompositionandthemolecularstructureofPA.Withtheincreasingofwaxcontentandthefractionofwaxwithlargecarbonnumber,thedepressiveeffectgreatlydecreased.TheaveragemolecularweightofPAaffecteditsdepressiveeffectbycontrollingthesolubilityofPAinwaxycrudeoils:thesolubilityofPAincrudeoilsdecreasedwithincreasingtheaveragemolecularweightofPA,thusreducingtheinteractionsbetweenwaxesandPAmoleculesandinhibitingthedepressiveeffectofPA.ThebettermatchingthealkylsidechainofPAwiththecarbonnumberofwaxincrudeoils,thebetterdepressiveeffectofPA.Keywords:Polyacrylate;Pourpointdepressant;Crystallizationability;Waxcrystalmorphology;Depressiveeffect收稿日期:2008-05-04作者简介:杨飞(1979-),男,山东惠民县,讲师,博士。基金项目:国家863计划资助项目(2006AA09Z302)。3通讯联系人。第2期杨飞等.聚丙烯酸酯降凝剂对含蜡原油降凝规律的研究21我国盛产高含蜡原油,其凝点高、低温粘度大流变性复杂,这给原油开采及输送带来很大困难。在原油中添加高分子降凝剂可以改变原油中蜡晶的结晶形态(结晶大小和形状),使其不易形成空间网络结构,从而达到降凝、减粘,改善含蜡原油低温流变性的目的。目前,高分子降凝剂已广泛应用于含蜡原油的管道输送工艺中,但由于降凝剂分子结构的多样性和原油组成的复杂性,人们对降凝剂降凝规律的认识仍显不足。聚丙烯酸酯(简称PA)是一类梳状结构的聚合物降凝剂,其合成与表征受到人们的广泛关注[1-4]。为指导EVA类降...