SOLUBILISED WAXES AND THEIR INFLUENCE ON THE FLOW PROPERTIES OF LUBE OIL BASE STOCKS

ABSTRACT

The physico-chemical properties of Lubricating oil base stocks (LOBS) are generally influenced by the type/nature and concentration of solubilised waxes present in them. Detailed composition of the solubilised waxes, saturates and aromatics present in LOBS and its distillate fractions has been sludied. Further the influence of these solubilised waxes and as well of saturates/aromatics on the flow properties particularly pour point, viscosity and viscosity temperature relationship of LOBS sample and its distillate fractions have been investigated. The response of a commercial pour point depressant additive with varying composition of solubilised waxes in lube oil base stock sample has also been studied.     

The Structural Characterization of Saturate,Aromatic, Resin,and Asphaltene Fractions of Batiraman Crude Oil

Abstract

The structural characterization of fractions of Batiraman crude oil, which is the heavy crude oil from a field in the southeastern part of Turkey, was investigated. Batiraman crude oil and its saturate, aromatic, resin, and asphaltene (SARA) fractions were seperated. Treatment of crude oil with n-heptane provided the separation of asphaltene. Maltene was collected by evaporating the n-heptane from the filtrate. Then, maltene was separeted into saturates, aromatics, and resins by SARA technique. Maltene was separated into saturate, aromatic, and resin fractions using column chromatography. SARA fractions were quantified on a weight percent basis. Fractions of Batiraman crude oil were characterized by elemental analysis, proton nuclear magnetic resonance (¹H NMR) analysis, electrospray ionization mass spectrometry (ESI-MS), and Fourier transform infrared (FTIR) spectroscopy techniques.     

Change of the chemical and physical properties of heavy oil before and after CO2 treatment

In order to improve the heavy oil displacement effect by CO₂ flooding, the change of the chemical and physical properties of heavy oil before and after CO₂ treatment is systematically investigated by indoor simulation experiment. Experimental results show that CO₂ treatment can decrease the amount of the saturates but increase that of the aromatics, and yet has little impact on those of resins and asphaltenes. Besides, the corresponding consequence is that there has an increase in the viscosity of the heavy oil and the particle size of the asphaltene micelle, and a decrease in the conductivity of the heavy oil and n-heptane systems and the stability of the asphaltene micelle after CO₂ treatment. The conclusions can provide a certain guidance for high-efficiency development of heavy oil reservoir by CO₂ flooding.     

SOLUBILISED WAXES AND THEIR INFLUENCE ON THE FLOW PROPERTIES OF LUBE OIL BASE STOCKS

The physico-chemical properties of Lubricating oil base stocks (LOBS) are generally influenced by the type/nature and concentration of solubilised waxes present in them. Detailed composition of the solubilised waxes, saturates and aromatics present in LOBS and its distillate fractions has been sludied. Further the influence of these solubilised waxes and as well of saturates/aromatics on the flow properties particularly pour point, viscosity and viscosity temperature relationship of LOBS sample and its distillate fractions have been investigated. The response of a commercial pour point depressant additive with varying composition of solubilised waxes in lube oil base stock sample has also been studied.     

STRUCTURAL CHARACTERIZATION OF ARABIAN HEAVY CRUDE OIL RESIDUE

ABSTRACT

The residue (370°C+) from Arabian Heavy Crude Oil was separated into four fractions, asphaltenes, resins, aromatcis and saturates. The four fractions were found to be free of artifacts and analytically significant in themselves. Each fraction was further characterized by elemental analysis, infrared spectroscopy, n.m.r. spectroscopy and mass spectroscopy. The aromatics are the major constituent of the residue and the ratio of asphaltenes, resins, aromatics and saturates is about 2:3:8:3. The strucutral characterization study led to the conclusion that asphaltene fraction is maximum hydrogen deficient followed by resins, aromatics and saturates thus suggesting larger degree of ring condensation in the structure of asphaltenes than resins and aromatics.     

大庆、辽河催化油浆窄馏分受热相分离行为的研究

利用石油大学（北京）重质油加工国家重点实验室开发的超临界体萃取分馏技术将大庆,辽河催化油浆分离得到多个窄馏分。从中间选出族组成（饱和分,芳香分,胶质＋沥青质）有代表性的6个窄馏分,3个选自大庆催化油浆,3个选自辽河催化浆,利用热台显微镜考察了它们的受热相分离行为,实验结果表明,高温时催化油浆中的芳香分有缩合生焦的倾向,较低温度下由于芳香分的强胶溶能力使得油浆生焦倾向减缓,在芳香分含量相同条件下,胶质沥青质含量高,油浆的生焦倾向就会增大。     

郑王稠油四组分组成和油-水界面膜黏弹性的关系

采用化学分离和元素分析方法分析了郑王稠油的饱和分、芳香分、胶质、沥青质（SARS）的组成,测定了含有分离的四组分的油 水体系的界面扩张黏弹性,考察了振荡频率及组分浓度对油 水体系界面扩张黏弹性的影响。结果表明,含郑王稠油四组分的油 水体系的界面扩张模量均随振荡频率增大而增大,随组分质量分数的增大先增加后减小。含胶质、沥青质组分的油 水体系所形成的界面膜以弹性膜为主,抵抗形变能力更强;油 水体系中饱和分浓度增大,主要体现在其体相浓度增加,弹性模量变化不大,而黏性模量逐渐增大。含郑王稠油四组分的油 水体系的扩张相角均随振荡频率的增加逐渐减小,扩张相角由小到大的油 水体系为含沥青质的、含芳香分的、含胶质的、含饱和分的油 水体系。沥青质是四组分中对油 水体系界面膜黏弹性影响最大的组分。       

Prediction of asphaltene precipitation from n-alkane diluted crude oil by using PC-SAFT equation of state

The precipitation tendency of heavy organics such as asphaltene has posed great challenges for petroleum industry, and thus study of asphaltene precipitation amount and formation conditions seems to be necessary. One of the most common approaches for prediction of asphaltene precipitation is using thermodynamic models. In this study a PC-SAFT equation of state (EOS) is used to predict asphaltene precipitation in two Iranian dead oil samples. Asphaltene content is obtained by filtration method of the oil samples diluted with specific concentrations of different normal alkanes. Also liquid-liquid equilibrium is used for characterization of oil sample into one heavy phase (asphaltene) and another light phase (saturates, aromatics, and resin). Calculations show that the developed model is highly sensitive to interaction parameter between oil fractions. Prediction results were improved due to using Chueh-Prausnitz equation. The results indicate good potential of PC-SAFT EOS in the prediction of asphaltene precipitation in crude oil samples diluted with different normal alkanes. The model error is <5% and the model precision is increased by reducing the number of normal alkane carbons.     

孤东油田稠油极性四组分测定方法及其乳化特性研究

稠油油藏高效、经济的开发一直是油田企业研究的技术难题之一,胜利孤东油田稠油油藏由于其胶质、沥青质含量均高于国内主要稠油平均值,有其特殊性,开采难度也更大.文章通过大量室内实验,确定了稠油极性四组分(饱和分、芳香分、胶质、沥青质)的测定方法和分离方法,并采用元素分析、红外光谱分析等手段深入研究了稠油极性四组分的乳化特性、乳化剂对四组分乳化特性的影响.研究结果表明,孤东稠油极性四组分乳状液稳定性次序为饱和分＜沥青质＜芳香分＜胶质＜原油,原油中胶质与沥青质分子通过氢键形成的缔合,对原油的黏度有重要影响.乳化剂OP对稠油极性四组分均具有强烈的乳化促进作用,使W/O型乳状液转变为O/W型,达到了乳化降黏效果.     

ANALYSIS AND PHYSICO-CHEMICAL CHARACTERIZATION ON CHINESE OIL SAND BITUMENS

Abstract

The extraction of four Chinese oil sands from Sinjiang and Inner Mongolia Autonomous Regions with Dean-Stark extractor were investigated. The mineral composition and sand grain distribution were determined and the bitumens were separated into saturates, aromatics, resin-I and resin-II, asphaltenes. The structure parameters and molecular model were made for the bitumens. Elemental analysis, molecular weight, FTIR, 1H-NMR were made for the bitumen fractions. The results show that the molecular structure of Mongolia bitumens have more polycyclic aromatics than that of Sinjiang bitumen. It is believed that the extraction of Sinjiang oil sand bitumen by hot alkaline water is much easier than Mongolia oil sand due to the difference of the viscosity of bitumen, the molecular structure and other physico-chemical properties of the bitumens.     

ASPHALTENIC CRUDE OIL CHARACTERIZATION: AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF RESINS ON THE STABILITY OF ASPHALTENES

ABSTRACT

High performance liquid chromatography (HPLC) and Thin Layer Chromatographic (TLC) latroscan were used to characterize an asphaltenic stock tank oil (STO) from the North Sea. The whole STO was separated into saturates, aromatics, polars 1 (resins 1), polars 2 (resins 2) and asphaltene fractions. The separated resins (1) and the more polar resins (2), also termed asphaltene peptizing agents, were further characterized by HPLC in terms of their neutral, basic, pyrrolic and acidic components. Resins (1) and resins (2) were mixed in different proportions with whole (original) STO; the resulting mixtures were tested for asphaltene onsets of precipitation due to n-C5 injection at 25° C and 690 kPa. Results of these tests are presented and the observed trends are explained in terms of resins characters and/ or major constituents.     

酸化-混凝-催化氧化联合处理钻井废液研究

采用灰色关联熵分析法研究了胜利油田稠油黏度与其极性四组分含量和极性组分偶极矩的关联。同时通过改变实验油样乳状液的含水率及温度,探究了稠油组成性质与其乳状液反相点的关联。结果表明：稠油极性四组分含量与其黏度关联度的顺序是：沥青质〉胶质〉芳香分〉饱和分;稠油极性组分偶极矩与其黏度的关联度顺序是：沥青质〉胶质〉芳香分。随着稠油胶质、沥青质含量的增大,油水界面张力的降低、油滴Zeta电位绝对值的增大,乳状液含水率的反相点及温度的反相点逐渐升高。     

DEVELOPMENT OF HIGH-PERFORMANCE HEAVY OIL HYDROCRACK1NG CATALYSTS: CHARACTERIZATION OF ATMOSPHERIC RESIDUE FEED

ABSTRACT

The characterization results of the atmospheric residue obtained from Saudi Arabian Light crude oil show the complex nature and composition of this material. The distillation results showed that about 50 percent of Arab Light crude is the atmospheric residue. The elemental analysis of the residue showed that high amount of carbon, sulfur and nitrogen is present along with heavy metals such as nickel and vanadium. The determination of hydrocarbon types by HPLC exhibited that 12% polars and 27% aromatics are present along with 6% asphaltenes. Nuclear magnetic resonance study conducted on the residue and its fraction provides a detailed composition in terms of aliphatic and aromatic nature of the residue and its fractions. The results showed that the residue contains 21% aromatic and 79% aliphatic carbon. The aliphatic carbon is present in saturates and as side chains of aromatic and polar molecules whereas the aromatic carbons are those in the ring structure. Asphaltenes separated from the residue were characterized for their different properties to understand its complexity. The use of electron spin resonance spectroscopy provides determination of the free radicals present in the residue. Asphaltenes were analyzed using the state-of-the-art high temperature high pressure electron spin resonance (ESR) technique in the temperature range 20 to 625 °C and at 30 and 50 bar hydrogen pressure. The ESR determination at 30 bar shows that me pressure was not enough to prevent the boiling of the asphaltene and thus a decrease in the spin concentration was observed beyond 350 °C temperature. The data at 50 bar pressure showed the adequacy of this pressure for ESR measurement. The PMRTA analysis of asphaltene showed a decrease in residual hydrogen with increasing temperature.     

超稠油改质降黏分子模拟及机理

为了研究微乳液纳米镍对特超稠油的改质降黏效果,利用分离改质降黏前、后的特超稠油,对反应前、后稠油重质组分沥青质及胶质的平均分子量、元素及核磁共振进行测定,结合化学分子模拟软件Hyperchem对特超稠油改质降黏进行了分子模拟及机理研究。模拟实验结果表明:特超稠油经过改质降黏反应后,其黏度大幅度下降,氢/碳原子比升高;沥青质与胶质分子的尺寸明显减小,沥青质分子量降低幅度较大;改质降黏剂能与特超稠油重质组分稠环芳烃盘状中心核沥青质接触,并导致其稳定的盘状芳环结构破坏,从而使沥青质分子的聚集状态得以改善,胶质分子稳定沥青质分子的作用增强。     

RESID HYDROTREATING CHEMISTRY Analyses of Hondo Feed and Product Fractions

Abstract

The chemistry of resid upgrading was studied by following the changes caused by hydrotreatment of Hondo 450°F+ resid, its separated asphaltenes and maltenes, and polar, aromatic, and saturate fractions. Both continuous and batch hydrogenations were studied, using two commercial resid hydrotreating catalysts.

At low reactor temperatures, the most important reactions are saturation of aromatics and removal of reactive heteroatoms. Increasing the temperature adds cracking reactions.

Detailed results can he explained by arbitrarily assigning to resid cuts the ranking:

saturates > aromatics > polar compounds > asphaltenes

and assuming that hydrotreating moves materials upward in the hierarchy. Each cut can form products only at or above its ranking. Only asphaltenes can give rise to asphaltenes in the products.

Asphaltenes are the most difficult resid fraction to treat, and they reduce the catalyst's activity for treating other fractions, possibly by blocking pores or adsorbing strongly on the catalyst's surface.     

稠油井下改质降黏开采中高效催化剂的研究与应用

 研究了油溶性水热裂解催化剂XAGD-2对稠油黏度、组成和平均分子量的影响。结果表明,该催化剂将过渡金属离子置于有机酸骨架上,具有油溶性,实现了均相催化,且合成方法简单,成本低廉,稳定性良好,催化效率高,使用温度范围广。在反应温度在200℃,反应时间为24 h,催化剂XAGD-2及供氢剂加入量分别为0.3% (wt)和0.1% (wt)时,可使胜利稠油降粘80%以上。稠油经处理后,其饱和烃、芳香烃质量分数增加, 胶质和沥青质质量分数明显下降,从而导致稠油的黏度降低,平均分子量减小。胜利油田现场应用证明,油溶性催化剂体系XAGD-2可有效改善热采稠油油藏吞吐开发效果,实现井下催化降黏,提高原油产量。     

PHYSICAL AND CHEMICAL CHARACTERIZATIONS OF ASPHALTENES FROM DIFFERENT SOURCES

ABSTRACT

Asphaltenes and resins are two of the several, but important, heavy organics present in petroleum fluids. Asphaltenes are operationally defined as the non-colatile and polar fraction of petroleum that is insoluble in n-alkanes (i.e., n-pentane). Conversely resins are defined as the non-colatile and polar fraction of petroleum that is soluble in n-alkanes (i.e., n-pentane), and aromatic solvents (i.e., toluene), and insoluble in ethyl acetate. A commonly accepted view in the petroleum chemistry is that crude oil asphaltenes form micelles which are stabilized by adsorbed resins kept in solution by aromatics. Two key parameters that control the stability of asphaltene micelles in a crude oil are the ratio of aromatics to saturates and that of resins to asphaltenes. When these ratios decrease, asphaltene micelles will coalesce and form larger aggregates. The precipitation of asphaltene aggregates can cause problems such as reservoir plugging and wettability reversal.     

Changes in the subfractional composition of heavy oil asphaltenes under aquathermolysis with oil-soluble CO-based catalyst

The asphaltenes extracted from the heavy oil sample and products of non-catalytic and catalytic aquathermolysis in the presence of cobalt-based catalyst precursors and hydrogen donor were investigated. Five fractions of asphaltenes and carbene-carboid were obtained by solvent extraction method. In the products of catalytic aquathermolysis processes, the content of resins and asphaltenes decreased, while the content of light hydrocarbon fractions (saturates and aromatics) slightly increased in contrast with non-catalytic processes. This result is due to intensification of destructive hydrogenation reactions, mostly on the weak –C–S–C– bonds of resins and asphaltenes. This study revealed redistribution phenomenon between the asphaltene fractions and decrease in average molecular mass of all asphaltene fractions under catalyst influence.     

380#燃料油的四组分分析及其油水界面张力研究

采用氧化铝吸附色谱柱将380#燃料油分成饱和分、芳香分、胶质和沥青质四组分;用元素分析、凝胶色谱、红外光谱和核磁共振等技术对四组分进行分析和结构表征;测定了燃料油及其组分模拟油的油水界面张力,考察了水相pH值、盐浓度对燃料油及其组分模拟油油水界面张力的影响。结果表明,380#燃料油中芳香分含量最多,沥青质和胶质含量约30 %。沥青质比胶质含有更多的杂原子,相对分子质量更大。沥青质氢碳原子比n(H)/n(C)最小,芳香碳率fA最大。红外谱图表明,沥青质比胶质含有更多的羟基、氨基和羧基等官能团,故分子间氢键作用强烈。四组分油水界面张力大小顺序为：饱和分>芳香分>胶质>沥青质,沥青质界面活性最大。由于380#燃料油及其组分中酸性基团占优势,在强碱性条件下它们与水的界面张力大幅下降。水相盐浓度对380#燃料油及其组分的界面活性影响不大。     

STRUCTURAL CHARACTERIZATION OF ARABIAN HEAVY CRUDE OIL RESIDUE

The residue (370°C+) from Arabian Heavy Crude Oil was separated into four fractions, asphaltenes, resins, aromatcis and saturates. The four fractions were found to be free of artifacts and analytically significant in themselves. Each fraction was further characterized by elemental analysis, infrared spectroscopy, n.m.r. spectroscopy and mass spectroscopy. The aromatics are the major constituent of the residue and the ratio of asphaltenes, resins, aromatics and saturates is about 2:3:8:3. The strucutral characterization study led to the conclusion that asphaltene fraction is maximum hydrogen deficient followed by resins, aromatics and saturates thus suggesting larger degree of ring condensation in the structure of asphaltenes than resins and aromatics.