The effect of dynamic cooling on the flow properties of PPD-treated crude oil

Abstract

By means of DSC, test of flow parameters, and microscopic observation, this paper studied the relation between the influence on the low temperature flow properties and that on the waxy crystal of the PPD-treated crude oil due to different final temperature of dynamic cooling. It has been experimental confirmed that the influence caused by the final temperature of dynamic cooling on low temperature flow properties and waxy crystal vary from the different final temperature of dynamic cooling. With this temperature increases, the depressive effects first get worse, then improved and finally kept nearly unchanged at higher temperature.     

Some biosurfactants used as pour point depressant for waxy egyptian crude oil

Two bacteria (B1 and B2) were isolated from soil-contaminated sites. The surface properties of biosurfactants produced by these bacteria were determined. These bacteria were given a good resistance to NaCl concentration up to 20%. The surface activity was detected with maximum value at pH7 with B1, whereas B2 was not affected by the change pH (3–12). The biosurfactants of these bacteria were added as a mixture or individual to crude oil given the good result in reducing the pour point. The infrared spectrum of wax or asphaltene fractions of Egyptian crude oil untreated and treated with biosurfactants was detected.     

新型胺解原油降凝剂PSMA的合成与性能评价

采用分散聚合法以聚乙烯吡咯烷酮(PVP)为分散剂,无水乙醇为分散介质,合成了马来酸酐和甲基丙烯酸十八酯为单体的二元共聚物(PSMA-a),并对聚合物用苯胺进行酰胺化处理,得到降凝剂PSMA。采用傅里叶红外光谱和热失重对聚合物的结构和热稳定性进行表征。以大庆油田原油为实验对象,采用差示扫描热分析、石油凝点试验仪和石油产品运动黏度计对其进行了降凝降黏性能的研究。通过正交试验确定了最佳的单体配比、反应温度、反应时间和引发剂用量。实验表明,当降凝剂质量浓度为750mg/L,PVP用量为单体总质量分数的8%时,具有最佳的降凝降黏效果。     

丙烯酸十八酯-苯乙烯共聚物对含蜡原油改性效果与分子动力学模拟

合成了单体配比不同的丙烯酸十八酯-苯乙烯共聚物(OAS)降凝剂,采用实验与分子动力学模拟相结合的方法对降凝剂的性能进行评价.实验结果表明,OAS降凝剂的降凝减黏性能随丙烯酸十八酯比例的增加呈现出先增大后减小的趋势.在2000 mg/kg加剂量下,苯乙烯与丙烯酸十八酯摩尔比为1:3的降凝剂OAS-4能使含蜡原油凝点降低4...     

Multifunctional lube oil additives based on maleic anhydride

Copolymer of maleic anhydride with 1-decene was synthesized by using azobisisobutyronitrile as an initiator in toluene solvent and the prepared copolymer was reacted separately with different long chain amines (n-octyl amine, n-decyl amine, and n-dodecyl amine) to get three copolymers. The performance of the polymers in different base oils was evaluated as viscosity modifier (VM) also called viscosity index improver, pour point depressant (PPD), and dispersant by standard ASTM methods. The molecular weight of the polymers was determined by gel permeation chromatography. The TGA value was determined by the standard ASTM method. It was found that the efficiency of the polymers as a VM and dispersant increases with increasing the molecular weight of the polymers as well as with increasing the alkyl chain length. However, the efficiency as a PPD increases with decreasing molecular weight of the prepared polymers and with the decreasing the alkyl chain length.     

Synthesis of cyclohexanone-alcohol hemiketals and evaluation as flow improver for waxy crude oil

In this paper, four novel cyclohexanone-alcohol hemiketals (KL-1, KL-2, KL-3, KL-4) as waxy crude oil flow improver have been prepared by cyclohexanone and 1-pentanol, 1-Hexanol, 1-heptanol, 1-octanol. Evaluation results demonstrate the hemiketal compounds have obvious effect on the viscosity and pour point of Henan crude oil. DSC analysis showed that waxing point and waxing peak decreased to a certain degree in 0.05% hemiketal solutions. Wax crystal morphology analysis indicated the four hemiketals played a role of nucleation in the process of waxy crude oil decoagulation, and in that way acts as waxy crude oil flow improver.     

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。     

Effective flow improving agents for waxy crude oil

The comb-like copolymer-polyhedral oligomeric silsesquioxane (POSS) nano-composite PPDs, including POA-POSS, POA-VA-POSS, POA-MA-POSS and POA-St-POSS, were first synthesized via in-situ reversible addition-fragmentation chain transfer (RAFT) polymerization and characterized by FT-IR, NMR and TGA methods. Subsequently, the effects of the nanocomposite PPDs on rheology of a waxy crude oil were studied. Results showed that POA-VA-POSS is the most efficient PPD among the nanocomposite PPDs, which can depress the pour point, gelation point, apparent viscosity and yield stress of the crude oil to the lowest. Associated with the microstructure of crude oil, the rheo-logical improving mechanisms of the copolymer-POSS nanocomposite PPDs are discussed.     

Biodegradable multifunctional additives for lube oil: Synthesis and characterization

Homopolymers of isodecyl acrylate and isooctyl acrylate and copolymers of each of them with β-pinene (BP) were synthesized and characterized by spectral, thermogravimetric, and gel permeation chromatographic analysis. Pour point depressant (PPD) and viscosity index improver (VII) properties were tested with additive-doped base oil in terms of pour point (PP) and viscosity index (VI), respectively. Although the isodecyl acrylate polymers were thermally more stable than the isooctyl acrylate polymers, the latter showed higher VI and PPD efficiency. VI and PP values of the additive-doped base oils depend on the nature of mineral base oils as well as on the type and concentration of VII. In addition, introduction of BP moiety in the acrylate backbone has induces excellent biodegradability in the above polymers.     

苏丹三七区块原油降凝降粘技术研究

苏丹三七区块原油属于高蜡、高粘原油,原油中的蜡含量、碳原子分布和组成、胶质和沥青质均影响降凝剂的降凝效果。为了确保苏丹长输管线的安全输送,根据原油的油品性质及其分析结果,筛选出了一种对苏丹原油具有良好改性效果的原油降凝剂SL2。试验研究结果表明,在混合油中加入SL2复合降凝降粘剂1000mg/L,可使原油凝固点由40℃降至30℃,温度在50℃时,降粘率大于30%,使原油低温流动性明显改善。     

Biocompatible multifunctional lubricating oil additives

Six copolymers of different concentration of dodecyl acrylate and 1-decene with sunflower oil were prepared and their characterization was carried out by spectral, thermogravimetric, and viscometric analysis. Performance evaluation indicates that the polymers effectively act as pour point depressant and viscosity modifier. The viscosity index and pour point values depend on the nature of mineral base oils, polymer type, and also on the concentration of the additives in solution. Biodegradability test was also carried out and as anticipated, the sunflower oil copolymers showed a biodegradable nature in the additive.     

Improvement of rheological properties of Algeria crude oil by addition of extra-light crude oil and a surfactant agent

Abstract

Effect of surfactant and extra-light crude oil addition on the rheological behaviors of an Algeria crude oil in order to improving its flowability were studied at low temperature. These rheological properties include steady flow behavior, yield stress and viscoelastic behavior. An AR-2000 rheometer was employed in all of the rheological examination tests. Results show that Toluene and extra-light crude oil addition causes a strong reduction in viscosity, the yield stress and can effectively increase of crude oil transport capacity. The toluene addition gets its best flow capacity and lowest viscosity at 6%. The extra-light crude oil addition obtains its best flow capacity and lowest viscosity at 50%. The viscoelasticity character of the crude oil has indicate a significantly influence by the addition of Toluene and extra-light crude oil.     

剪切作用与加剂原油粘度关系的数学模型

分析了剪切作用对加剂大庆原油粘度的影响规律,建立了剪切后加剂原油粘度与剪切过程中粘性流动熵产关系的数学模型.根据剪切效应的一般规律及机理,提出了近似确定模型中参数的简易方法.按照此方法,只须测定一定温度下空白原油的粘度或表观粘度、未剪切时加剂原油的粘度或表观粘度,及在某一个剪切温度下及某一个粘性流动熵产条件下原油的粘度或表观粘度,即可近似确定该数学模型中的参数,从而预测在不同温度时剪切后的原油在该温度下的粘度或表观粘度.结合含蜡原油粘度与温度关系机理模型,还可以预测同一加剂原油经受剪切后在其他温度下的粘度.对中原原油和加剂轮南丘陵混合原油加剂试验数据的验证结果表明,该模型有较好的预测准确性.     

树枝状长链酯的合成及其作为原油流动改性剂性能研究

以低代树状聚酰胺-胺和系列丙烯酸长链酯为原料,通过分子设计合成了6种具有树状结构的原油流动改性剂。采用傅里叶红外光谱、核磁共振氢谱和元素分析对其结构进行了表征,并研究了系列树枝状长链酯对原油流动性能的影响,主要分析了树状长链酯对原油凝点和流变性能的影响。结果表明,树枝状长链酯对原油流动性的影响不仅与其端基烷基链长度有关,而且与其代数也有关。端基烷基链越长,添加树状长链酯原油体系的凝点和表观粘度降低的越明显;含有8 个支化长链的1.5代树状长链酯对降低原油凝点和表观粘度的效率高于含有4个支化长链的0.5代树枝状长链酯。相同条件下,添加1.5代树状十八酯原油体系的原油凝点和表观粘度高于添加其它1.5代树枝状长链酯的原油体系。     

一种新型原油降凝剂的研究

由乙烯、醋酸乙烯酯和乙烯醇聚醚组成的三元共聚物(WHP)是一种新型高分子表面活性剂型原油降凝剂.这种原油降凝剂既具有聚合物的特点,又有一定的表面活性,与某些常用的降凝剂,如EVA、聚丙烯酸高碳醇酯等相比,这种降凝剂无论对含高碳蜡(C₃₇-C₆₃)的吐哈原油和新疆混合原油,还是含一般蜡的江汉原油、鲁宁线原油和中洛线原油均表现出良好的降凝效果.例如,对吐哈原油在加药量为50mg/l时,一般原油降凝剂没有降凝效果,而WHP可以将原油凝固点从17℃降至10℃;而对新疆混合原油,当加药量为20mg/l时,WHP可以将原油凝固点从11℃降至-15℃而一般最好的降凝剂只能降至-8℃,即使对凝固点比较高的江汉原油,当加药量为100mg/l时,一般降凝剂只能将原油凝固点从34℃降至22℃,而WHP则可降至14℃.此外,WHP对鲁宁线原油还有一定的降粘效果,在加药量为40mg/l时,在30℃测定的降粘幅度为25.2%,而一般降凝剂最大的降粘幅度为14%.在室内模拟鲁宁线原油流动的情况下,原油加入WHP后依次经过多次慢速(80r/min)和快速(1500r/min)搅拌剪切后,原油凝固点回升幅度有较大的降低,且粘度的回升幅度也有所改善.     

锦州高含蜡原油降凝剂的筛选及现场应用

锦州原油高含蜡量高,凝点普遍在20℃以上,低温流动性差。为了保证冬季的安全输送,对实验室内开发研制的G5系列降凝剂进行了筛选,得到降凝效果最好的G51,并对影响其降凝效果因素进行了分析研究。实验结果表明,最佳加剂温度为60℃,合理的加剂浓度为400mg／L,可使原油的凝点由原来的22℃降至13℃,并且降凝剂具有良好的静态稳定性和配伍性,能保证管道的安全运行。     

江苏油田B1断块原油降凝剂研究

江苏油田B1断块原油属于高含蜡、高胶质、高沥青质原油,具有高凝、高黏特点,平均凝固点41.5℃、析蜡点59～60℃,温度敏感性强。针对该区块原油特性,开展井筒降凝、降黏工艺和配方研究,进行了降凝降黏剂的评价和配比,优选了合成的复配型降凝剂KD-50（Ⅳ）,确定合理添加浓度,考察在不同温度下对B1断块原油的降黏效果。室内实验结果表明：添加降凝降黏剂后,低温流动性明显改善,凝点、反常点和低温表观黏度均有较大幅度降低,在40℃加剂后的降凝降黏率达80%以上,具有较好的推广应用价值。     

BEM系列原油流动性改进剂的研制

通过对EVA的醋酸乙烯含量、熔融指数对含蜡原油的降凝影响的研究 ,探讨EVA对含蜡原油的最佳加入量以及不同的结构表面活性剂对原油降凝剂抗重复加热和抗剪切能力的作用 ,BEM降凝平均相对分子质量与含蜡原油蜡碳数分布之间的关系等。研制的BEM降凝剂广泛用于鲁宁线、中洛线等多条管输管道     

Multifunctional biodegradable lube oil additives: Synthesis,characterization, and performance evaluation

Copolymers of different concentration of decyl acrylate and 1-decene with rice bran oil were prepared and their characterization was carried out by spectral (NMR, IR), thermogravimetric, and gel permeation chromatography analysis. Performance evaluation of them in lube oil indicates that the polymers effectively act as pour point depressant and viscosity modifier. The viscosity index and pour point values depend on the nature of mineral base oils, polymer type, and also on the concentration of the additives in solution. Biodegradability test was also carried out and as anticipated, the rice bran oil–copolymers showed excellent biodegradable nature among the additives.     

柴油降凝剂对柴油感受性的影响分析

在柴油中加入降凝剂是一项提高轻油收率、增加经济效益的成熟技术.该技术在国内多家炼油企业的实际应用结果表明,对拓宽馏程、提高柴油的产量和质量、增加经济效益的效果显著.文中对降凝剂的加入量、储存安定性等影响因素做了研究分析.