不同原油界面活性组分的分离及表征

用极性分离法将胜利油田孤东1#、孤东4#原油和大庆原油分离为饱和分、芳香分、胶质、沥青质组分(S、Ar、R、As)。孤东1#和孤东4#沥青质组分质量分数(14.43%、11.35%)明显高于大庆原油沥青质组分质量分数(0.09%),而饱和分组分质量分数(47.08%、46.54%)低于大庆原油饱和分质量分数(68.08%)。孤东1#和孤东4#原油的原油组分(S、Ar、R、As)氧的质量分数、酸值由大到小的排序为:沥青质>胶质Ⅰ>芳香分>饱和分。而大庆原油的原油组分酸值由大到小的排序为:胶质Ⅰ>沥青质>芳香分>饱和分;大庆原油的饱和分组分中氧质量分数较低,饱和分中氧质量分数在原油氧中所占比例最高(0.375%),饱和分中的氧化物对大庆原油的界面活性影响不可忽视。在3种原油所有原油组分中,孤东1#原油沥青质的酸值最大(16.45 mg KOH/g沥青质),说明孤东1#原油沥青质组分含有较多酸性基团,反应活性较强。色-质分析结果表明,孤东原油饱和分正构烷烃在C10-C37呈双正态分布,大庆原油饱和分正构烷烃主要分布在C10-C38,基本呈正态分布。     

孤东原油组分的界面张力测定

按常规四组分分离法将孤东1#原油分离为饱和分、芳香分、胶质、沥青质,它们在原油中的质量分数分别为:45 88%,22 45%,14 73%,14 43%。将各组分在原油中所占的质量分数的十分之一和煤油配制成模拟油,模拟油与蒸馏水、碱水〔w(Na2CO3)=1 2%)〕体系的界面张力分别为:35 700,13 360;24 520,4 630;22 760,5 610;19 380,0 056mN/m。并对各分离组分进行了红外光谱、元素组成、相对分子质量测定。结果表明:界面张力的大小与各组分中的含氧量有关,含氧量越高,界面张力越低。沥青质是孤东1#原油的主要活性物质;w(沥青质)=3%时,模拟油与碱水〔w(Na2CO3)=1 2%〕体系的界面张力为0 0053mN/m。     

沙特原油活性组分的结构对油水界面性质的影响

测定了从沙特原油中分离出的胶质和沥青质的红外、紫外光谱和相对分子质量。对含有胶质、沥青质的模拟油和模拟水体系,测定了其界面张力和界面剪切黏度。胶质和沥青质的相对分子质量分别为497和1 786;光谱分析结果表明,沥青质比胶质含有更多的芳香环结构。含胶质和沥青质体系的界面张力分别是33.205 8 mN/m、31.732 5 mN/m,相差不大。对于界面剪切黏度,沥青质体系远大于胶质体系,同在100 mg/L,胶质体系剪切速率在0-0.5 rad/s时,界面剪切黏度最大不超过0.002 5 mN/m,而沥青质体系剪切速率在0.3 rad/s下,界面剪切黏度最大值大于1.000 0 mN/m,并且其曲线具有吸附曲线的特征,沥青质体系具有较强的界面膜,其界面膜的形成经历了从液态扩张膜到液态凝聚膜的变化过程。界面膜强度的大小与界面活性物质的相对分子质量的大小和芳香环结构含量的多少有关。     

聚合物3530S对坨一原油各组分油水界面性质及乳状液稳定性影响

用界面张力仪、表面粘弹性仪和Zeta电位仪研究了聚合物3530S对胜利坨一原油各组分模型油与模拟水间的界面特性及乳状液稳定性的影响规律。结果表明,沥青质及胶质模型油与模拟水间的界面张力低于蜡组分模型油,原油中的界面活性组分主要为沥青质和胶质。聚合物加入模拟水后,含有聚合物的模拟水与沥青质、胶质及蜡组分模型油之间的界面剪切粘度与界面张力均上升,油滴表面的Zeta电位降低。沥青质和胶质模型油与含聚合物3530S的模拟水所形成的W/O乳状液较蜡组分模型油所形成的W/O乳状液更稳定。     

渣油及其组分黏度的分子层次组成关联研究

渣油由于自身的黏度大和流动性差制约其加工和运输,所以渣油高黏度的来源成为探究的关键。本研究把不同渣油分离成SARA (饱和分、芳香分、胶质、沥青质)四个组分并进行黏度和分子组成的关联研究。研究结果表明:从组分含量来看,渣油黏度影响的灰色关联顺序为:沥青质>饱和分>胶质>芳香分。饱和分黏度远小于渣油的黏度,说明饱和分是渣油体系主要的稀释剂。从组分分子层次来看,发现饱和分的黏度贡献主要来源于环烷烃的贡献,环数越多对饱和分黏度影响越大。芳香分的黏度贡献主要来源于N1O1类和N1类化合物的分布。除了金属元素Ni及Fe元素,胶质黏度很大程度受O1类化合物的影响。     

HPAM对孤岛原油及沥青质油水界面特性影响的研究

用界面张力仪、表面粘弹性仪和Zeta电位仪测定了孤岛原油及沥青质模型油的界面特性,研究了部分水解聚丙烯酰胺(HPAM)浓度对这些界面特性的影响。结果表明,加入HPAM会使孤岛原油模型油及沥青质模型油与模拟水间的界面张力上升,但随着HPAM浓度增加,界面张力基本保持不变。当水溶液中HPAM的质量浓度大于5.0mg/L时,孤岛原油模型油及沥青质模型油与模拟水的界面剪切粘度随HPAM浓度增大明显增加,随着体系老化时间从1h增加到12h,其界面剪切粘度也有所增加。另外,HPAM还使得原油及沥青质模型油与模拟水体系所形成的O/W型乳状液的油珠表面Zeta电位变大。     

原油组分对采出水乳状液稳定性的影响

采用界面张力仪、表面粘弹性仪和浊度仪,研究了原油组分对桩西采出水乳状液稳定性的影响.结果表明,当各组分在模拟油中的浓度相同时,沥青质的界面张力最小,蜡组分的最大,胶质的居中;在相同的剪切速率下,沥青质的界面剪切粘度最大,蜡组分的最小,胶质的居中.原油组分浓度增加,组分模拟油油水界面张力减小,界面剪切粘度增加,乳状液稳定性增强.分离组分模拟油乳状液稳定性的强弱顺序依次为:沥青质组分>胶质>蜡组分.     

辽河稠油与孤岛稠油油-水界面张力的比较

采用吸附色谱法,将辽河和孤岛稠油按极性分为饱和分、芳香分、胶质、沥青质。考察了它们的化学组成和界面张力,比较了两个组分系列在不同条件下油-水界面张力的变化规律。结果表明：辽河稠油组分中的芳香共轭成分以及含氧、氮的极性基团较多,界面活性较强;在不同的水包油乳状液体系中,辽河稠油的界面活性比孤岛的强,且沥青质的界面活性最强;pH值对辽河稠油活性组分的油-水界面张力的影响总体上略大于对孤岛稠油活性组分的影响,即对界面活性高的影响较大。     

超声波对重质油4组分分布的影响

渣油的饱和分、芳香分、胶质和沥青质4组分的分布直接影响各工艺的产品产率与产品质量,对重质油加工具有十分重要的意义.探索超声波作用对油品4组分含量变化的影响,为进一步探索超声波对重质油4组分的化学作用提供依据.结果表明:超声波作用对重质油4组分的分布有影响,可以促进饱和分和芳香分质量分数的增加,胶质和沥青质质量分数的降低.本试验范围内,超声温度50～60℃,超声时间15 min,超声频率28 kHz,超声功率200 W,与原料油相比,重质油4组分中饱和分和芳香分质量分数增加率分别为5％和4％,胶质和沥青质质量分数分别减少了2.5％和7.5％.     

原油沥青质分子结构与乳化特性的关联研究

以核磁共振氢谱为基础,用改进的Brown-Ladner法计算六种原油沥青质的平均结构参数和平均分子式,关联原油水乳状液的表观黏度。结果表明:沥青质的芳香取代率在0.37～0.54之间,芳香环系周边碳的取代率在0.40～0.53之间,RA/RN均大于1。与穆尔班原油沥青质相比,胜利、文森特原油沥青质的芳香核结构较小,而支链烷烃数量较多;达里亚沥青质芳香核结构较少,支链数目较多;新文昌的支链比穆尔班沥青质的要长;巴林沙中沥青质的芳香结构较为致密。可以推测:沥青质分子结构中含硫官能团在原油水乳状液反相时起到交联作用,增大了沥青质界面膜强度;含氧官能团是亲水基团。     

石油磺酸盐对原油界面性质及其乳状液稳定性的影响

The influence of petroleum sulphonate （TRS） on interfacial properties and stability of the emulsions formed by formation water and asphaltene, resin and crude model oils from Gudong crude oil was investigated by measurement of interfacial shear viscosity, interfacial tension （IFT） and emulsion stability. With increasing petroleum sulphonate concentration, IFT between the formation water and the asphaltene, resin and crude model oils decreases significantly. The interfacial shear viscosity and emulsion stability of asphaltene and crude model oil system increase for the petroleum sulphonate concentration in the range 0.1% to 0.3%, and decrease slightly when the concentration of the surfactant is 0.5%. There exists a close correlation between the interfacial shear viscosity and the stability of the emulsions formed by asphaltene or crude model oils and petroleum sulphonate solution. The stability of the emulsions is determined by the strength of the interfacial film formed of petroleum sulphonate molecules and the natural interfacial active components in the asphaltene fraction and the crude oil. The asphaltene in the crude oil plays a major role in determining the interfacial properties and the stability of the emulsions.     

INVESTIGATION OF EMULSIFICATION AND COALESCENCE PHENOMENA IN CRUDE OIL/ALKALINE WATER SYSTEMS

Emulsihcation and coalescence processes in crude oil/alkaline water systems were examined and their influence on alkaline Hood enhanced oil recovery was assessed. Emulsification mechanisms were investigated under static and dynamic conditions using microvisual techniques. Coalescence rates were measured using the inclined spinning drop tensiometer. The relative impact of interfacial viscosity on coalescence processes was determined through measurements of interfacial shear viscosities. In addition, the influences of chemical composition on ease of emulsification, coalescence rate, and interfacial shear viscosity were examined.

Ease of emulsification was influenced by the composition of the crude oil, the electrolyte concentration, and the partitioning coefficient of surfactants. Coalescence was primarily affected by processes which disrupted the crude oil/water interface. Alkaline flood oil recovery efficiency was promoted by emulsification followed by rapid coalescence to form a stable oil bank.     

The influence of NaOH on the stability of paraffinic crude oil emulsion

The alkaline–surfactant–polymer flooding using sodium hydroxide as the alkali component to enhance oil recovery at the on shore oil fields at Daqing in China has brought new problems for the oil industry. Even though, the reservoir contained paraffinic crude oil, the alkali added formed stable water-in-crude oil emulsion and de-emulsification process was necessary to separate oil and water.The problems related in the enhanced oil recovery process using the alkaline–surfactant–polymer flooding technique in the Daqing oil field have been investigated in the laboratory using fractions of Daqing crude oil. The oil was separated into asphaltene and aliphatic fractions and then used in an additive free jet oil to form model oils. The emulsion stability of each of the water-in-model oil emulsions formed between water or 0.6% sodium hydroxide solution and model oil was investigated. The interfacial properties such as interfacial tension and interfacial pressure of the systems were also measured. These in combination with the chemical nature of the fractions were used to get insight into the problem related to the ASP flooding technique using sodium hydroxide as the alkaline component.The study reveals that the sodium hydroxide solution reacts with fatty acids in the aliphatic fraction of the crude oil and/or with the fatty acids formed from the slow oxidation of long chain hydrocarbons, and form soap like interfacially active components. These accumulate at the crude oil–water interface and contribute to the stability of the oil/water emulsion.     

胶质和沥青质油水界面膜黏弹性

引　言原油被乳化形成乳状液后 ,油 /水界面膜黏弹性是决定乳状液稳定的关键因素 界面膜主要是由胶质、沥青质及极性分子组成的 研究表明 ,这些膜类似于固态或半固态 ,它在液滴聚并过程中降低了液膜的排液速度 ,从而提高了乳状液的稳定性[1,2 ] 原油在油藏内部形成过程中 ,胶质和沥青质沉积在岩石表面形成亲油膜 ,这层油膜对原油黏附力大 ,阻碍原油流动 ,因此研究界面膜的性质对化学驱油也有着重要意义 　近年人们对油相中胶质和沥青质与水相形成界面膜性质的研究主要在以下几个方面 :①界面张力与原油乳状液稳定性关系 ;②不同比例胶质…