加拿大油砂沥青喷雾造粒溶剂体系的选择

以正戊烷+正己烷、正戊烷+环戊烷2个系列混合物作为溶剂,采用溶剂沉淀法从加拿大油砂沥青中得到沥青质,通过对沥青质SARA族组成、元素组成、平均分子结构、分子片层堆积结构的测定,考察了溶剂混合比例对所得沥青质性质的影响。结果表明,随着正己烷或环戊烷掺入比例的增加,沥青质的收率显著降低,软化点明显提高;正戊烷+环戊烷混合溶剂更适宜作为加拿大油砂沥青喷雾造粒的溶剂体系,正戊烷中加入少量的环戊烷就能达到沥青喷雾造粒的要求。在正戊烷中掺入体积分数10%的环戊烷,可将脱油沥青收率降低4百分点,软化点相应升高10~12℃,从而生产出外观形态良好的沥青粉,可以作为加拿大油砂沥青喷雾造粒的溶剂体系。     

加拿大Athabasca油砂中部分沥青质油不易分离的原因

1. Introduction Commercial recovery of bitumen from oil sands iscurrently achieved by means of water based separationprocesses. While most of these separation methods arebased on the Hot Water Extraction Process, the need toconserve energy has resulted …     

中低温煤焦油沥青质的分析表征

采用XPS、XRD、FT IR、13C NMR、元素分析等手段分析表征了中低温煤焦油正庚烷沥青质(CT C7沥青质),系统研究了CT C7沥青质表面元素的赋存状态、相对含量以及其晶体结构。结果表明,该沥青质的主要结构为多环稠合芳香烃并富含杂原子,其芳香度(fa)明显大于一般原油沥青质;烷基链间距和芳香片层直径值较小,其芳环上烷基侧链短而少且难以形成堆积结构;表面C主要以sp2和sp3碳的形式存在,二者摩尔分数之和达699%,以C=O和COO-基团存在的C较少。该沥青质表面的杂原子以O原子为主,N和S原子较少,其中含氧官能团主要是酚羟基和醚氧基,摩尔分数达619%。含氮官能团主要以吡啶氮(N 6)和吡咯氮(N 5)为主,二者摩尔分数之和为805%;含硫官能团中,噻吩硫、烷基硫比较多,摩尔分数之和达517%。该C7沥青质表面加氢难度较大的N 6、N 5和噻吩硫的摩尔分数低于石油沥青质,这可能是煤焦油加氢工艺中N、S脱除效率较高的原因之一。     

The Prediction of Asphaltene Precipitation from Crude-Oils

Abstract

Asphaltene precipitation is undesirable deposition that causes difficult problems in oil production and transportation. A molecular thermodynamic model is proposed for predicting the asphaltene precipitation under live oil conditions and at a wide range of pressures and different solvent ratios. In this model, it is assumed that the precipitation phenomenon is a reversible process, and an equation of state is employed for phase behavior prediction. The vapor and liquid equilibrium calculations are performed separately and sequentially. The characterization of unknown-heavy fraction of petroleum (C₇₊) is obtained by the generalized molar mass distribution model, in which C₇₊ is represented by four pseudocomponents. The two heaviest pseudocomponents of C₇₊ are identified as asphaltenic components, are also considered as precipitating components. The model is verified by its ability to prediction of asphaltene precipitation in different thermodynamic conditions. It has been shown that the calculated results are in good agreement with the experimental data.     

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Abstract

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C–450°C temperature interval. Thermal degradation continues to finish until 650°C.     

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C-450°C temperature interval. Thermal degradation continues to finish until 650°C.     

Thermal Degradation of Asphaltene and Infrared Characterization of Its Degraded Fractions

Petroleum asphaltene and its thermally degraded fractions are characterized using thermal analysis and infrared spectrometry, respectively. Thermal analysis of asphaltene has demonstrated that heating rate is important in studying thermal degradation of asphaltene. Asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25 to 1,000°C at a heating rate of 1°C/min and below. The products from thermal degradation of asphaltene at three different temperature intervals are collected. The collected fractions are characterized using a Fourier transform infrared spectrometer. The fraction collected between 220 and 350°C demonstrates similar infrared spectrum to that of asphaltene, however, with less aromatic properties. The fraction collected between 350 and 450°C resembles the undegraded asphaltene most based on the infrared spectra obtained. The fraction collected between 450 and 650°C demonstrates a spectrum that is totally different from those of the undegraded asphaltene and the other two fractions. In addition, a high degree of oxidation is observed on all of the three degraded fractions of asphaltene.     

Thermal Degradation of Asphaltene and Infrared Characterization of Its Degraded Fractions

Abstract

Petroleum asphaltene and its thermally degraded fractions are characterized using thermal analysis and infrared spectrometry, respectively. Thermal analysis of asphaltene has demonstrated that heating rate is important in studying thermal degradation of asphaltene. Asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25 to 1,000°C at a heating rate of 1°C/min and below. The products from thermal degradation of asphaltene at three different temperature intervals are collected. The collected fractions are characterized using a Fourier transform infrared spectrometer. The fraction collected between 220 and 350°C demonstrates similar infrared spectrum to that of asphaltene, however, with less aromatic properties. The fraction collected between 350 and 450°C resembles the undegraded asphaltene most based on the infrared spectra obtained. The fraction collected between 450 and 650°C demonstrates a spectrum that is totally different from those of the undegraded asphaltene and the other two fractions. In addition, a high degree of oxidation is observed on all of the three degraded fractions of asphaltene.     

Modeling of Asphaltene Deposition During Miscible CO2 Flooding

The authors present the results of numerical tests and simulations to investigate and analyze the likelihood of asphaltene precipitation and deposition during CO₂ flooding in a reservoir. The effects of asphaltene precipitation on oil properties such as oil viscosity and density during miscible CO₂ flooding process were elaborated by using Winprop software of Computer Modeling Group. Also oil properties change during CO₂ miscible flooding by numerical slim tube were investigated by a compositional simulator (GEM). A fluid sample of Saskatchewan Reservoir that had been flooded miscibly with CO₂ was chosen for performing the sensitivity analyses. The results showed that asphaltene precipitation reduces the oil viscosity and density that is in favor of production increasing. On the other hand asphaltene deposition causes resistance in oil production due to porosity and permeability reduction. The competition between these two effects declares the positive or negative effect of asphaltene on recovery that could be different for each reservoir. The results also show that decreasing the rate of CO₂ injection leads to an increase in asphaltene deposition near the injective well. Due to this phenomenon in higher injecting rates the increment in well bottom-hole pressure becomes less.     

委内瑞拉稠油沥青质的XPS研究

以委内瑞拉稠油沥青质为原料,采用X射线光电子能谱（XPS）定性和定量分析了沥青质表面含碳、氧、氮、硫官能团结构和含量。结果表明,委内瑞拉稠油沥青质表面的碳原子主要以C-C和C-H形式存在,约5%的碳原子与氧原子结合;含氧官能团中羰基为主要含氧结构,其氧原子数量占氧原子总数量的44%左右,C-O和COO的氧原子数量分别占氧原子总数量的29%和27%;含氮官能团中,约59%的氮为弱碱性或非碱性的吡咯类氮,剩余为强碱性的吡啶类氮;含硫官能团中,脂肪类硫约占57%,其余为噻吩类硫。从委内瑞拉稠油沥青质表面杂原子官能团摩尔数量来看,羰基摩尔分数最多(>1%),其次是吡咯氮和脂肪硫(均约1%),C-O基、羧基、吡啶氮和噻吩硫摩尔分数基本相同（均约0.7%）。     

Dispersion of Asphaltene Precipitation in Egyptian Crude Oil Using Corrosion Inhibitors

Three corrosion inhibitors are examined in this work to control asphaltene precipitation in Egyptian heavy crude oil. Dodecylbenzenesulfonic acid (DBSA), 4-nonylphenyl-polyethylene glycol, and synthetic cationic gemini surfactant: N₂,N₃-didodacyl-N₂,N₂,N₃,N₃-tetramethylbutane diaminium bromide displayed highest capacity to inhibit asphaltene deposition. The H¹-NMR spectroscopy was used to confirm the chemical structure of the synthetic inhibitor. The efficiency of the studied additives as corrosion inhibitors are evaluated by weight loss method using the same crude oil. The effect of the mentioned corrosion inhibitors as asphaltene inhibitors is studied. The studied inhibitors are with dual nature for inhibition of both corrosion and asphaltene precipitation.     

Monitoring Bitumen Upgrading,Bitumen Recovery,and Characterization of Core Extracts by Hydrocarbon Group-type SARA Analysis

Abstract

Hydrocarbon group-type analyses are presented in this work for characterization of samples related to the Province of Alberta's abundant bitumen reserves that demand more effective ways of utilization and valorization. The main objective of the study is the evaluation of thin layer chromatography with flame ionization detection (TLC-FID) for rapid hydrocarbon group-type monitoring of bitumen samples and determination of the feasibility of each method for application with very small sample amounts. TLC-FID is a known technique for hydrocarbon (HC) group-type analysis. Different methods of utilization of TLC-FID are assessed here. The analytical techniques employed and data obtained are presented and compared. HC group types are presented in term of saturates, aromatics, resins, and asphaltenes (SARA). Applications are shown for three types of studies related to bitumen: with respect to ultradispersed catalytic bitumen upgrading; solvent-based enhanced bitumen production (Vapex); and characterization of organic extracts from reservoir cores. Techniques are evaluated and validated for each utilization and the preferred methodology indicated.     

Structural characterization of asphaltenes derived from nigerian bitumen using the x-ray diffraction technique

Petroleum asphaltenes consist of complex hydrocarbon molecules that pose a marked difficulty in the production of crude oils. They tend to flocculate and precipitate during oils refinery and this stimulates considerable interest in the elucidation of their molecular structure for improved processing. In this investigation, five bitumen samples obtained from oil sand outcrops at five localities in Nigeria were used. These were treated with n-pentane that necessitates the precipitation of asphaltene. The different asphaltene samples were analyzed by the x-ray diffraction technique to obtain their various structural parameters. The parameters were determined from the peaks of the gamma (γ) band, graphene (c = c) or (002) band and the (10) or (11) band in the diffraction spectra of the respective samples. Slight variations in the distance between the aliphatic chains and the distance between the aromatic sheets were observed for three of the samples, while the remaining two presented significant variations in the structural parameters. Variations in the average number of carbon atoms per aromatic units correspond to the variation in the size and number of aromatic units and aliphatic chains. The variations consequently determined the level of processing necessary to improve the heavy oil (bitumen).     

Study of Resin Adsorption onto Asphaltene and Silica-Asphaltene Particles

Abstract

We present a methodology to study the adsorption behavior of resins on asphaltenes, which we call silica-asphaltene complex methodology (SACOM), and compare it to a methodology regularly used by many researchers (Acevedo et al., 1995 Acevedo, S., Ranaudo, M., Escobar, G., Gutiérrez, L. and Ortega, P. 1995. Adsorption of asphaltenes and resins on organic and inorganic substrates and their correlation with precipitation problems in production well tubing. Fuel., 74: 595–598. [Crossref], [Web of Science ®] , [Google Scholar]; González et al., 2003 González, G., Neves, G., Saraiva, S., Lucas, E. and Anjos de Sousa, M. 2003. Electrokinetic Characterization of Asphaltenes and the Asphaltenes-Resins Interaction. Energ. Fuel., 17: 879–886. [Crossref], [Web of Science ®] , [Google Scholar]; León et al., 2002 León, O., Contreras, E., Rogel, E., Dambakli, G., Acevedo, S., Carbornani, L. and Espidel, J. 2002. Adsorption of Native Resins on Asphaltene Particles: A Correlation between Adsorption and Activity. Langmuir, 18: 5106–5112. [Crossref], [Web of Science ®] , [Google Scholar]; Marczewski et al., 2002 Marczewski, A. and Szymula, M. 2002. Adsorption of asphaltenes from toluene on mineral surface. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 208: 259–266. [Crossref], [Web of Science ®] , [Google Scholar]; Pereira et al., 2007 Pereira, J. C., López, I., Salas, R., Silva, F., Fernández, C., Urbina, C. and López, J. C. 2007. Resins: The Molecules Responsible for the Stability/Instability Phenomena of Asphaltenes. Energ. Fuel., 21: 1317–1321.  [Google Scholar]) that we call traditional methodology. Three isotherms of resins adsorbed on the complex substrates (asphaltene and its colloidal fractions A₁ and A₂ adsorbed on silica) were built, analyzed, and then compared with two isotherms built by applying a traditional methodology where resins were adsorbed on two organic substrates: asphaltene and its fraction A₁.     

塔河超稠油胶质、沥青质形貌分析

用环境扫描电子显微镜观察稠油非烃组分胶质和沥青质的形貌,分析结果表明,胶质分子之间、沥青质分子之间以及二者之间可以发生相互作用,形成结构较大的颗粒,胶质颗粒之间连接紧密,沥青质颗粒之间较分散。胶质和沥青质的含量和平面堆砌结构是影响稠油粘度的因素。     

Prediction of Asphaltene Precipitation from Empirical Models

Asphaltene precipitation in the reservoir has proved to be a difficult problem to define and study. Field conditions conducive to precipitation include normal depletion, acid stimulation, gas-lift operations, and miscible flooding. Asphaltene precipitation is generally believed to be an irreversible process, which is the main reason it can have a profound impact on production operations. Investigations into asphaltene precipitation have been impeded by a shortage of experimental data and information on precipitation mechanisms. The aim of this work is to generate empirical models with other thermodynamic models to describe and predict precipitate formation models with a variety of reservoir fluids. Experimental asphaltene precipitation data on several live-oil at reservoir conditions were measured to study the effects of temperature, pressure, and composition on precipitate formation and the relationships between critical properties. Data generated by the model can be used to identify operating amount of asphaltene deposited under different conditions.     

SBS结构对改性沥青性能的影响

在试验装置上合成不同结构参数的SBS,进行沥青改性,考察了SBS结构形态、分子量、嵌段比、掺入量等与改性性能之间的关系.     

胶质沥青质相互作用浅析

为认识胶质沥青质之间的相互作用,以委内瑞拉、辽河减压渣油为研究对象,测定了向沥青质-甲苯溶液中加入不同量的胶质得到的溶液的黏度、电导率以及各自的分子量。结果表明,辽河和委内瑞拉减压渣油的沥青质浓度较低时各浓度的胶质对沥青质的作用主要以分散作用为主;而沥青质浓度较高时低浓度的胶质对沥青质主要以分散作用为主,但随着胶质浓度的增大,吸附作用大于分散作用。由此推断,胶质与沥青质间存在着吸附与解缔的平衡,当平衡打破后,两者的作用会发生变化。     

The Effect of Sodium and Organic Montmorillonites on the Thermal Aging Properties of Bitumen

Effect of sodium and organic montmorillonites on the thermal aging properties of bitumen was investigated by thin-film oven test and pressure-aging vessel test. The microstructures of montmorillonite and the binders were characterized by X-ray diffraction. The results show that the sodium montmorillonite (Na⁺-Mt) modified bitumen forms a phase-separated structure, while the organic montmorillonite (OMt) modified bitumen forms an intercalated structure. The thermal aging properties of bitumen are improved obviously with the introduction of montmorillonite. Compared with Na⁺-Mt, the changes of physical properties of bitumen are further decreased by OMt, indicating the good aging resistance of intercalated OMt modified bitumen.     

Prediction of Asphaltene Precipitation from Empirical Models

Abstract

Asphaltene precipitation in the reservoir has proved to be a difficult problem to define and study. Field conditions conducive to precipitation include normal depletion, acid stimulation, gas-lift operations, and miscible flooding. Asphaltene precipitation is generally believed to be an irreversible process, which is the main reason it can have a profound impact on production operations. Investigations into asphaltene precipitation have been impeded by a shortage of experimental data and information on precipitation mechanisms. The aim of this work is to generate empirical models with other thermodynamic models to describe and predict precipitate formation models with a variety of reservoir fluids. Experimental asphaltene precipitation data on several live-oil at reservoir conditions were measured to study the effects of temperature, pressure, and composition on precipitate formation and the relationships between critical properties. Data generated by the model can be used to identify operating amount of asphaltene deposited under different conditions.