江汉原油降凝剂的制备及其性能研究

利用溶液聚合反应合成了一系列丙烯酸酯类高蜡原油降凝剂,并对其降凝效果进行研究。研究结果表明：采用摩尔配比为6：3：1的丙烯酸十八酯,马来酸酐和醋酸乙烯酯组成的混合单体制备的三元聚合物高蜡原油降凝剂MVA-3对江汉原油具有明显的降凝效果,在加剂量为1000mg／kg时,可以使江汉原油的凝点降低12℃。高蜡原油降凝剂MVA-3能够同原油中的胶质和沥青质有效结合,可以降低原油中固有的胶质一沥青质聚集体在原油中的析出温度,改变原油中蜡的结晶方式,降低蜡结晶析出温度和蜡结晶析出速度,并能减少原油中蜡的析出总量。     

超临界CO2处理对长庆原油添加降凝剂效果的影响

利用超临界CO2(scCO2)与原油混相处理装置,模拟地层条件对长庆原油进行超临界CO2混相处理,通过对处理前后油样的四组分(SARA)、沥青质稳定性、蜡析出曲线、凝点、流变性分析及微观显微观察,从沥青质缔合状态与蜡结晶层面分析了超临界CO2处理对乙烯 醋酸乙烯共聚物(EVA)降凝剂添加到长庆原油作用效果的影响。结果表明,超临界CO2处理加剂原油相比未处理加剂原油具有更好的低温流动性能。超临界CO2处理会增加未加剂原油体系极性,增强沥青质缔合程度,使低温下蜡晶形貌更细小,恶化原油低温流动性,而超临界CO2处理后添加EVA降凝剂却使得蜡晶形貌向更加紧密的团簇转化。由于超临界CO2处理有利于EVA降凝剂进一步改善蜡晶形貌,故超临界CO2处理可以促进EVA降凝剂对长庆原油低温流动性的改善效果。     

降凝剂对南阳原油管壁蜡沉积特性的影响

以魏荆线管道所输送的南阳原油为研究对象,利用旋转式动态结蜡装置,考察了添加降凝剂对原油蜡沉积规律的影响。实验结果表明,添加降凝剂改变了蜡晶的生长历程,增大蜡晶体积并阻碍三维网状结构的形成,弱化了管壁沉积蜡晶的结构强度,减小了胶凝原油的屈服强度;在保持壁面温差、油品温度、旋转筒转速相同的情况下,在低流速区间,添加降凝剂会增大南阳原油的蜡沉积速率,在高流速区间则对管壁结蜡具有一定的抑制作用;降凝剂的添加使壁面剪切应力成为影响加剂南阳原油蜡沉积速率的主要因素。     

聚合物/微纳米复合含蜡原油降凝剂的研究进展

含蜡原油中蜡分子的结晶析出会使原油的低温流变性显著恶化,降低原油管输的安全性和经济性.添加少量的聚合物型降凝剂能够改变蜡分子的结晶习性,改善原油的宏观流动性.加降凝剂原油的凝点越低、低温黏度越小,意味着输送的能耗越低、安全性越高,因此人们对原油降凝剂的降凝降黏效果追求是无止境的.利用不同的微纳米颗粒,研制高效的聚合物/...     

聚丙烯酸酯降凝剂对蜡晶形态和电性质的影响

采用偏光显微镜和微电泳仪研究了聚丙烯酸酯降凝剂对蜡晶的形态和电性质的影响。结果表明，降凝剂的加入，使原油中的蜡结晶成小晶体，同时，改变了蜡晶的表面性质，降低了蜡晶的表面能。降凝剂加入原油后，降凝剂中的极性基团在蜡晶表面形成极性点，在其上优先吸附含蜡体系中的极性低分子物质，蜡晶表面产生定向电场，由于电性排斥使蜡晶高度分散而稳定存在，高度分散的蜡晶使原油的凝点和粘度下降。当降凝剂用量较低时，蜡晶表面的ζ电位随降凝剂用量的增加而增加；降凝剂的用量较高时，蜡晶表面ζ电位随降凝剂用量的增加趋势变缓；降凝剂用量达到一定值时，蜡晶表面ζ电位不随降凝剂用量的变化而变化。     

高凝原油降凝剂的制备及其降凝机理研究

 由丙烯酸十八酯、马来酸酐和醋酸乙烯酯三元共聚物的胺解改性物（MAVA）和乙烯-醋酸乙烯酯的共聚物（EVA）为原料,通过复配制备了一种高凝原油降凝剂(PPD),并对其降凝效果和降凝机理进行了研究。结果表明,所制备的高凝原油降凝剂对凝点为43℃的胜利原油具有明显的降凝效果,在加剂量为400?g/g时,原油的凝点降低了11℃;由原油中的沥青质和胶质所形成的聚集体结构是原油的蜡晶成核剂,降凝剂可以同原油中的沥青质和胶质结合形成新的沥青质-降凝剂-胶质聚集体结构,该聚集体结构作为加剂原油的蜡晶成核剂,可以改变蜡的结晶方式,延缓蜡晶的析出速率,大幅地降低了原油的凝点。     

降凝剂对原油中蜡晶形态的影响

 摘要：采用偏光显微镜观察降凝剂(PPD) 在不同添加量下原油蜡晶形态的变化;采用图像分析软件统计分析蜡晶的数目、颗粒直径等参数,实现了蜡晶大小及其分布特征的量化描述。结果表明,随着降凝剂的加入,原油中的蜡晶由不规则的大的片状、棒状形态逐渐变成大量小的、分散较均匀的结晶形态,原先占主导地位的大直径(9～13μm)蜡晶的质量分数由67.5%下降至0.01%,小直径(2～5μm)蜡晶的质量分数由8.5%上升至95.6%;降凝剂的加入阻碍了蜡晶相互连接搭桥成网,体系能量降低,形成空间网络结构的可能性较小,原油低温流变性得到明显改善。通过非线性回归可确定降凝剂添加量、蜡晶平均直径、降凝幅度的关系,其结果与实验结果吻合。     

双阳原油热处理中加入降凝剂的研究

以双阳原油为研究对象,选用EVA(乙烯-醋酸乙烯共聚物)作原料,用马来酸酐接枝改性,合成EJ-6降凝剂,采取在热处理中加入降凝剂的综合处理方法,考察了降凝剂合成的最佳反应条件和降凝剂用量及热处理温度对原油结晶状态及流动性的影响。结果表明,热处理中加入EJ-6降凝剂可使蜡的结晶状态发生明显变化。降凝剂用量仅100～500ppm,即可使双阳原油的凝点由原来的30～31℃降至7～9℃,原油的低温流动性大为改善。     

RESPONSIBILITY TO POUR POINT DEPRESSANT OF CRUDE OILS IN RELATION TO THEIR GROUP COMPOSITION

本文总结多年来降凝剂的研究工作,阐述了原油的族组成对原油加剂处理效果的影响。多蜡原油随着蜡含量的增加对降凝剂的感受性逐渐变差,高碳蜡(C     

梳型共聚物的相对分子质量调控及其对JENM原油 的降凝效果*

为降低高蜡型JENM原油的输送成本,合成了丙烯酸十八酯-丙烯酸二十二酯-马来酸酐梳型共聚物降凝剂,考察了降凝剂相对分子质量对降凝效果的影响,并通过优化反应条件实现对聚合物相对分子质量的调控,研究了加剂前后JENM原油的析蜡特性和蜡晶形貌的变化。研究表明,随着反应温度升高和反应溶剂用量增加,降凝剂的平均相对分子质量减小;随着引发剂用量的增加,降凝剂的平均相对分子质量先增大后减小。丙烯酸十八酯-丙烯酸二十二酯-马来酸酐降凝剂的平均相对分子质量约为14000时对JENM原油的降凝效果较好,典型优化合成条件为:反应温度100℃、溶剂用量77%、引发剂用量为单体质量的1%,合成的降凝剂加剂量为0.3%时,JENM原油凝点由30℃降至17℃,降幅为13℃;30℃时黏度由9.12 Pa·s降至2.24 Pa·s,降黏率为75%,显著改善了JENM原油的低温流动性。结合DSC和显微分析发现,降凝剂的加入使JENM原油析蜡点和析蜡峰温降低,凝点处析蜡量增加。降凝剂的极性基团抑制了蜡晶生长,促进了蜡分子的分散,使晶种在更低温度才开始析出。同时,由于蜡晶更加细小,析蜡量较大时才使原油失去流动性,从而有效降低了原油凝点。图11表2参18。     

聚合物型原油降凝剂的结晶性能研究

摘要: 采用红外光谱仪、核磁共振波谱仪对聚合物的合成特征基团进行了表征，并采用X射线衍射仪对不同型号蜡及降凝剂的结晶性能进行了分析测试，结果表明蜡晶与聚合物的结晶性能密切相关，结晶度不同，蜡晶分散效果不同，对原油降凝性能也就有所区别，当两者结晶性能状态匹配时蜡晶分散效果变好，降凝降粘性能最佳，并通过考察原油体系热性能和低温流动性能进行了证实。     

USE OF DSC TO STUDY THE FLOW PROPERTIES OF HYDROCRACKED BASE STOCKS AND LUBRICATING OILS

The differential scanning calorimetry (DSC) technique was found useful in assessing the effect of different processing conditions on the wax content and the wax-type of hydrocracked base stocks. The DSC thermograms showed a wide crystallization peak, in the range from -40 to -20°C, indicating the presence of paraffinic wax molecules. The second, narrow crystallization peak at about -75°C, indicated the presence of lower melting isoparaffinic or branched-type wax molecules. The DSC technique was used to study the onset wax crystallization temperature and the wax formation in hydrocracked base stocks containing different chemistry pour point depressants. The fumarate-vinylacetate (FVA) pour point depressant was not as effective as polymethacrylate (PMA) type chemistry. A decrease in depressed pour points of hydrocracked base stocks was found to follow a decrease in the onset wax crystallization temperature. In engine oil formulations containing hydrocracked base stocks, a decrease in depressed pour point was also found to follow a decrease in the onset wax crystallization temperature. For pour point depressants used in lubricating oils, the mechanism of decreasing the onset wax crystallization was found to be more important than the mechanism of suppressing the wax formation.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART II EFFECT OF WAX COMPOSITION AND CONCENTRATION ON THE DEW AXED CRUDE OILS WITH / WITHOUT ADDITIVES

In this part of the work the effect of wax concentrations on the rheologica! properties of the dewaxed Duliajan (Assam) and Lingaia crude oils have been studied. The dewaxing of the crude oil was done by removing n-paraffins from the crude oil by urea adduction. The urea adducted n-paraffins concentrate-the wax- was characterized by its carbon number distribution. The urea non adducted oil portion - the denormalized crude oil (DNO)- was characterized for its pour point. The wax in different concentration was then added in the DNO and the change in the rheological properties like pour point, yield stress and plastic viscosity were studied using a Haake Rota Viscometer. The effect of carbon number distribution, i.e. the composition of the wax, on these rheological properties was also investigated. Four different commercial pour point depressanl additives have been used to study their effects on the pour point, yield stress and plastic viscosity of the reconstituted (wax mixed DNO) crude oils.

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point of the DNO, and the DNO composition has a small effect. However, as seen in the Part I of this paper, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the composition of the DNO. The additives have shown better response in the DNO having more aromatic concentrate, as has been found in the case of Duliajan (Assam) DNO.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART II EFFECT OF WAX COMPOSITION AND CONCENTRATION ON THE DEW AXED CRUDE OILS WITH / WITHOUT ADDITIVES

ABSTRACT

In this part of the work the effect of wax concentrations on the rheologica! properties of the dewaxed Duliajan (Assam) and Lingaia crude oils have been studied. The dewaxing of the crude oil was done by removing n-paraffins from the crude oil by urea adduction. The urea adducted n-paraffins concentrate-the wax- was characterized by its carbon number distribution. The urea non adducted oil portion - the denormalized crude oil (DNO)- was characterized for its pour point. The wax in different concentration was then added in the DNO and the change in the rheological properties like pour point, yield stress and plastic viscosity were studied using a Haake Rota Viscometer. The effect of carbon number distribution, i.e. the composition of the wax, on these rheological properties was also investigated. Four different commercial pour point depressanl additives have been used to study their effects on the pour point, yield stress and plastic viscosity of the reconstituted (wax mixed DNO) crude oils.

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point of the DNO, and the DNO composition has a small effect. However, as seen in the Part I of this paper, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the composition of the DNO. The additives have shown better response in the DNO having more aromatic concentrate, as has been found in the case of Duliajan (Assam) DNO.     

潍北高凝点原油降凝降黏剂的研制

实验室自制的三元共聚物AMV-22与EVA复配,添加SLA-107作助剂,制备适用于胜利油田潍北区块高凝点原油的降凝剂AMVES。实验考察了该降凝剂对原油的降凝降黏效果。DSC热分析结果表明,AMVES加量为1000 mg/L时,可使原油凝点从48℃降低到37℃,析蜡点降低2℃。流变性曲线表明原油的剪切稀释作用随温度升高显著增强,当剪切速率大于100 s^-1后黏度基本不变,降凝剂可以大幅降低启动原油的屈服应力。偏光显微镜图显示原油温度越低,蜡晶网状结构越致密,交联度强,黏度大,流动性差;加AMVES之后原油中蜡晶变为团簇状颗粒,原油的流动性增强。由此可见降凝剂AMVES作用于蜡晶使其三维网状结构破坏,从而有效降低原油凝点和黏度。     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART I WITH AND WITHOUT POUR POINT DEPRESSANT ADDITIVES

ABSTRACT

The yield stress, plastic viscosity and apparent viscosity and the dependence of the latter on the shear rate have been studied at different temperatures below pour point of Lingala (Krishna-Godavari basin, Eastern coast), Duliajan (Eastern region of Assam), Rava (Godavari basin) and Bombay-High (off-shore western region) indigenous crude oils

Four different commercial pour point depressant additives have been used to study their effects on the pour point, yield stress and plastic viscosity

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point, and crude base composition has a small effect. However, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the liquid matrix. As the temperature is lowered both the yield stress and plastic viscosity increase in case of each crude oil. However, the magnitude is dependent on the nature of the crude oil. With pour point depressant additives, the yield stress and plastic viscosity are decreased and this decrease is a function of nature of the liquid matrix of the crude oil and concentration of the additive     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART I WITH AND WITHOUT POUR POINT DEPRESSANT ADDITIVES

The yield stress, plastic viscosity and apparent viscosity and the dependence of the latter on the shear rate have been studied at different temperatures below pour point of Lingala (Krishna-Godavari basin, Eastern coast), Duliajan (Eastern region of Assam), Rava (Godavari basin) and Bombay-High (off-shore western region) indigenous crude oils

Four different commercial pour point depressant additives have been used to study their effects on the pour point, yield stress and plastic viscosity

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point, and crude base composition has a small effect. However, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the liquid matrix. As the temperature is lowered both the yield stress and plastic viscosity increase in case of each crude oil. However, the magnitude is dependent on the nature of the crude oil. With pour point depressant additives, the yield stress and plastic viscosity are decreased and this decrease is a function of nature of the liquid matrix of the crude oil and concentration of the additive     

阴离子聚合物St-OMA的合成和应用

采用阴离子聚合法合成苯乙烯（Styrene）-甲基丙烯酸十八酯（Octadecyl methyl acrylate）的二元共聚物St-OMA,评价了不同聚合条件下的聚合物对苏丹原油的降凝效果。通过偏光显微镜和图片处理软件对加剂前后原油中的蜡晶形态和分布进行微观分析,原油中蜡晶由大量片状、针状形态改变为颗粒状,蜡晶尺寸较小,蜡晶间也密实,分散得更细更匀称。这表明降凝剂的加入确实改变了原油中蜡的结晶形态,使析出的蜡晶尺寸变小变密,从而改善了原油的流动性,降低了原油的凝点。