Features of the composition of vanadyl porphyrins in the crude extract of asphaltenes of heavy oil with high vanadium content

Features of changes in the content of nickel and vanadium in heavy oils and their asphaltenes are shown for various fields of Volga-Ural region (Russia). The change in the content of vanadyl complexes in the studied asphaltenes upon increase of vanadium content was demonstrated. Several polar solvents (acetone, N,N-dimethylformamide, isopropanol, acetonitrile) are compared as extractants to obtain crude extracts of vanadyl porphyrins from asphaltenes with vanadium content of 0.44 wt%. The opportunity of more efficient extraction of vanadyl porphyrins from asphaltenes is shown by deposition extraction method, particularly when using N,N-dimethylformamide. Absorption spectra and matrix-assisted laser desorption/ionization (MALDI) mass spectra of the extracts obtained were analyzed. For extracts with maximum content of vanadyl porphyrins, the presence of mainly etio- and deoxophylloerythroetioporphyrins was revealed. It was shown that proportion of etio-type vanadyl porphyrins does not exceed 75% of the amount of porphyrins of DPEP-type. A maximum of molecular weight distribution in both types falls on a homologue of vanadyl porphyrin C₃₁ containing nine carbon atoms in the alkyl substituents.     

Vanadium and paramagnetic vanadyl complexes content in asphaltenes of heavy oils of various productive sediments

Using the atomic absorption spectrometry and electronic paramagnetic resonance techniques, we have investigated the features of vanadium and vanadyl complexes content in asphaltenes of heavy oils of Permian and Carboniferous productive sediments in the Volga-Ural oil and gas basin deposits. The investigation has been carried out using the heavy oils example, where the asphaltene content ranges from 5.1 to 21.2 wt%, and vanadium content varies in the range of 0.009–0.165 wt%. The specificity of asphaltene–vanadium relationship has been found for heavy oils of various productive sediments. It has been demonstrated that vanadium and vanadyl complexes content in asphaltenes of heavy oils in separate productive sediments varies in the certain range limits.     

Removing of resins from crude oils

Crude oil contains four chemical group classes, namely saturates, aromatics, resins, and asphaltenes (SARA fractions). Resins fraction of crude oil comprises polar molecules often containing heteroatoms such as nitrogen, oxygen, or sulfur. Resin is a heavier fraction than aromatics and saturates. Resins are composed of fused aromatic rings with branched paraffin and polar compounds. The resin fraction is soluble in light alkanes such as pentane and heptane, but insoluble in liquid propane. The resins are adsorbed on a solid such as alumina, clay, or silica, and subsequently recovered by use of a more polar solvent and the oils (aromatics and saturates) remain in solution. The resins often coprecipitate with the asphaltenes in controlled propane deasphalting procedures. The composition of the resins can vary considerably and is dependent on the kind of precipitating liquid and on the temperature of the liquid system. The resins are adsorbed on a solid such as alumina, clay, or silica, and subsequently recovered by use of a more polar solvent and the oils (aromatics and saturates) remain in solution.     

油溶性枝型稠油降粘剂的合成与性能评价

针对目前油溶性稠油降粘剂存在的选择性强和降粘效果差等问题,研制了一种油溶性枝型稠油降粘剂,该降粘剂分子结构中含有极性基团和烷基。极性基团可以降低稠油中胶质和沥青质的氢键作用,烷基可以增加油溶性枝型稠油降粘剂的溶解能力,从而提高其降粘效果。油溶性枝型稠油降粘剂通过2步法合成得到,通过对其合成条件的讨论发现,该油溶性枝型稠油降粘剂的最佳合成条件为:乙二醇、环氧氯丙烷和十八酰氯的摩尔分数之比为4∶4∶1.5;第1步主链反应温度为110℃,反应时间为8h,促进剂N的质量分数为1.4%;第2步接枝反应温度为110℃,反应时间为14h。研制的油溶性枝型稠油降粘剂降粘率可达49%;红外光谱对其结构的表征结果显示,其结构与设计结构一致。     

Relationship of Light Absorption and Vanadium Content in Asphaltenes and Resins of Heavy Oils

Abstract

The relationship of the light absorption of asphaltenes and resins with vanadium content has been investigated on the example of heavy oils of various deposits. In the oils of various deposits in Permian and Carboniferous producing complexes of Volga–Ural oil-and-gas bearing basin, the asphaltene content varies from 5.3 to 21.2?wt %, while the vanadium content is from 0.009 to 0.165?wt %. It has been shown that there is a direct correlation of the light absorption of asphaltenes and vanadium content with the correlation coefficient of higher than 0.96 in the case of each producing complex. There is also a direct relationship between the light absorption of resins and vanadium content in the HOs under study with the correlation coefficient of higher than 0.92 in the case of each producing complex.     

Differentiation of heavy oils according to the vanadium and nickel content in asphaltenes and resins

The features of the distribution of vanadium and nickel between asphaltenes and resins have been revealed using heavy oils from Tatarstan and Samara oblast oilfields as an example. It has been shown that depending on the V and Ni content in asphaltenes and resins, heavy oils of different productive plays are divided into two separate groups. An increase in the V or Ni content of heavy oils is accompanied by an increase in the concentration of the respective metal in asphaltenes and resins. The intervals of variation in the V and Ni content of asphaltenes and resins of the oils attributed to each group have been determined. As the V concentration in asphaltenes increases, the V/Ni ratio also increases, a feature that is not characteristic of resins.     

稠油高黏因素的初步研究

分析了华北稠油、委内瑞拉稠油、轮古159稠油和新疆稠油4种稠油的密度、蜡含量、元素分布、酸值、数均相对分子质量和四组分分布等性质,并通过核磁共振H谱、电化学法、相对黏度法和表面张力法测定了4种稠油沥青质的结构、极性、缔合度和临界胶束浓度,并将上述性质与4种稠油的黏度进行了关联。研究表明,4种稠油的黏度:华北稠油<委内瑞拉稠油<轮古159稠油<新疆稠油,稠油密度、蜡含量、数均相对分子质量、结构、沥青质极性等性质与稠油黏度无直接联系,而稠油沥青质含量和沥青质缔合性大小顺序与稠油黏度大小顺序一致,稠油沥青质含量越高、沥青质缔合度越大、沥青质临界胶束浓度越小,稠油黏度越大。实验结果表明,稠油中沥青质的含量和沥青质的缔合性是影响稠油黏度的重要因素。     

Transformations of resins and asphaltenes during the thermal treatment of heavy oils

Changes in the properties and chemical structure of high-molecular-mass heteroatomic compounds (resins, asphaltenes) as a result of the thermal treatment of heavy oils from the Zuunbayan (Mongolia) and Usinsk (Russia) oil fields have been shown. The structural-group parameters of resins and asphaltenes isolated from crude oils and their thermolysis products have been determined on the basis of elemental analysis, molecular mass, and ¹H NMR data. It has been shown that the yield of gaseous, liquid, and solid products varies depending on the thermolysis time and temperature. A model for the thermal conversion of the high-molecular-mass components of petroleum is proposed and the rate constants (k) and activation energies (E) of the petroleum thermolysis reactions have been calculated. The competing routes of the conversion of petroleum components at different temperatures have been established.     

Gasoline- and diesel-like products from heavy oils via catalytic pyrolysis

Heavy oil is less expensive than light crude oil, but heavy oil is more expensive to obtain light oil products. Conventional light crude oil resources are decreasing, therefore heavy oil resources will be needed more in the future. There are huge differences from field to field for heavy oil deposits. In terms of final productive use, heavy oil is considered as an unconventional resource. Heavy oil upgrading depends on four important factors: catalyst selection, heavy oil classification, process design, and production economics. Heavy and extra-heavy oils are unconventional reservoirs of oil. Globally, 21.3% of total oil reserves are heavy oil. Heavy oil is composed of long chain organic molecules called heavy hydrocarbons. The thermal degradation of the heavy hydrocarbons in heavy oil generates liquid and gaseous products. All kinds of heavy oils contain asphaltenes, and therefore are considered to be very dense material. The most similar technologies for upgrading of heavy oils are pyrolysis and catalytic pyrolysis, thermal and catalytic cracking, and hydrocracking. The amount of liquid products obtained from pyrolysis of heavy oil was dependent on the temperature and the catalyst. Pyrolytic oil contains highly valuable light hydrocarbons as gasoline and diesel components range. The constant increase in the use of crude oils has raised prices of the most common commercial conventional products and consequently seeking for new alternative petroleum resources, like some unconventional oil resources, becomes an interesting issue. The mass contents of gasoline, diesel, and heavy oil in the crude oil are 44.6%, 38.3%, and 17.1%, respectively. The gasoline yield from the heavy oil catalytic (Na₂CO₃) pyrolysis is higher than the diesel efficiency for all conditions. The yield of gasoline products increases with increasing pyrolysis temperature (from 230°C to 350°C) and percentage of catalyst (from 5% to 10%). The yields of gasoline-like product are from 21.5% to 39.1% in 5% catalytic run and from 32.5% to 42.5% in 10% catalytic run. The yields of diesel-like product are from 9.3% to 29.8% in 5% catalytic run and from 15.5% to 33.7% in 10% catalytic run.     

稠油水热裂解反应催化剂适应性研究

以辽河油田的稠油为原料,环烷酸钴、环烷酸镍、柠檬酸钴或柠檬酸镍为催化剂,研究了稠油水热裂解反应催化剂在地层中的适应性。结果表明,催化剂与地层水的配伍性良好,不会对地层造成伤害。以柠檬酸钴为催化剂,稠油催化改质的反应条件为:温度240℃,时间24 h,稠油100 g,地层水30 g,催化剂摩尔浓度9×10-3mol/L;在此条件下,稠油降黏率最高(达到66.82%)。外加催化剂与油藏矿物具有协同效应,催化剂的加入能够强化矿物催化的稠油水热裂解反应。     

Demetallization and desulfurization of heavy oil residues by adsorbents

The purpose of the work is demetallization and desulfurization of heavy oil residues using adsorbents. Optimal parameters of the demetallization and desulfurization processes of heavy vacuum fraction of Pavlodar Petrochemical Plant LLP in the presence of a zeolite adsorbent containing vanadium oxide xerogel were established: temperature 340?°C, pressure 1?atm., bulk feed rate 1?h^?1. As a result of the process the extraction degree of vanadium, nickel and iron were 90, 70 and 60%, respectively, and the sulfur content decreased from 1.97 to 1.36%. Composition of the chemical adsorbent for demetallization and desulfurization of heavy vacuum fraction is established, too. Content of vanadium, iron and sulfur increase in composition of the adsorbent after treatment of heavy vacuum fraction, which confirms its high adsorption capacity regarding to metals and sulfur.     

Comparative thermal study of heavy crude oils by DSC

Crude oil represented 50% of primary energy consumption in the world at the beginning of this decade. For each reservoir existent of conventional petroleum or gas there is three times the amount of heavy crude oil in the planet. The present work investigates the thermal behavior of three heavy crude oils from Brazilian basins. It was possible to make an interesting comparison for the same petroleum due to the use of different DSC equipment, especially for the extra heavy crude oils. The petroleum sample with the lowest °API exhibited the highest value for specific heat capacity between all studied samples.     

稠油溶解气驱渗流特征物理模拟和数值模拟

为了改善稠油冷采开发效果,通过物理模拟实验和数值模拟方法研究了稠油溶解气驱渗流特征。首先测定了稠油和气体在不同压力下的界面张力,然后通过微观可视化实验和填砂管驱油实验研究了溶解气驱不同阶段渗流特征,最后对室内实验结果进行了数值模拟。研究结果表明：溶解气驱过程中气体逐渐由分散相聚并形成连续相;泡沫油会增大流体的弹性能量,有利于维持溶解气驱地层压力和增大生产压差,从而改善稠油溶解气驱开发效果。在室内实验的基础上,通过3种气体组分（溶解气、分散气和连续气）的转化来描述稠油溶解气驱渗流过程,数值模拟值和物理实验值拟合效果较好。     

Successful simulation of solution gas drive in heavy oils using conventional modeling

Detailed investigations into the production behavior of heavy oil reservoirs under foamy solution gas drive have been conducted extensively in the past. Historically, two approaches have been used to explain and model the solution gas drive in heavy oil reservoirs. The first approach is the base of foamy oil models in which solution gas drive is governed by parameters such as compressibility, viscosity, nonequilibrium phenomena, and the supersaturation. In the second approach, conventional modeling, which we show to be suitable for the history matching and prediction of the production data and macroscopic modeling of a series of depletion experiments (using a live combination of heavy oil and methane gas in a three-dimensional rectangular laboratory model), the foamy oil flow mechanism, dispersed flow of gas and the supersaturation are nonexistent. The conventional modeling uses parameters such as critical gas saturation, very low gas relative permeability, and the assumption of no supersaturation in the reservoir.     

催化降粘剂作用下河南稠油族组成变化研究

通过棒色谱、气相色谱、红外光谱等分析方法,对反应前后河南稠油族组成及其结构进行了测试,研究了水热催化裂解降粘剂作用下稠油的性能变化,实验表明稠油在水热裂解催化降粘剂作用下重质组分发生加氢裂解反应,胶质、沥青质减少,饱和烃、芳烃等轻质组分增加明显,稠油物性明显改善,为稠油催化降粘开采提供了依据。     

稠油碱驱机理的物理模拟和数值模拟

通过物理模拟实验和数值模拟方法研究了碱驱提高稠油采收率的驱替机理。首先通过实验测定了碱和稠油的界面张力,然后通过填砂管驱油实验评价了驱油效果,最后对室内物理模拟实验结果进行了数值模拟和历史拟合。研究结果表明,稠油碱驱过程中随着碱浓度的升高,原油采收率和压力降都随之升高。压力降的升高主要由于生成了油包水乳状液,增加了水流通道中水相的流动阻力,导致注入水流向未波及的区域,从而提高了稠油采收率。对稠油碱驱数值模拟时考虑了界面张力的降低、化学剂的吸附和油包水乳状液的形成。结果表明,模拟值和实验值拟合得较好。     

超临界流体萃取分馏仪—石油重质油的深度精密分离技术

超临界流体萃取分馏仪依据溶剂在超临界态下特有的反常冷凝原理设计而成,结合了萃取和分馏两大过程的特点。采用超临界丙烷、丁烷、戊烷作溶剂,分离过程完全由计算机控制,原料在萃取釜中由超临界流体萃取,分馏柱的温差作用产生的内回流可有效地改善分离选择性。线性升压程序使超临界流体的溶解能力由小到大,从而使重质油的馏分按分子量和极性大小顺序流出。超临界流体萃取分馏仪对高沸点物质的分离特别有效,可分离物质的常压当量沸点可达1000℃以上,已在石油重质油、润滑油、石蜡和地蜡、催化油浆、聚合物以及多种天然产物精密分离方面得到了广泛应用。     

Influence of the properties of resins on the interactions between asphaltenes and resins

The properties of two resins (Tahe resin and Liaohe resin) and their influences on the dispersion of two asphaltenes (Tahe asphaltene and Liaohe asphaltene) are investigated by laboratory experiments. The results indicate that the adsorption isotherms of two resins are accorded with the Freundlich absorption model. The shape of the curves obtained could be attributed to both multilayer adsorption of resins on asphaltenes surfaces and the penetration of resins into the microporous structure of the asphaltenes. Based on the combined results from the shape of the curves and chemical properties of resins, the relative adsorption quantity of Tahe resin is higher than that of Liaohe resin due to the stronger polarity of Tahe resin, and the effect of Tahe resin on the dispersion of asphaltene is stronger than that of Liaohe rein. The different properties of resin can directly lead to the difference of dispersion performance on asphaltene in crude oil, which is closely related to the chemical structure of resin. The more the number of aromatic structure of the resin, the stronger the effect of resin on the dispersion of asphaltene there is.     

世界稠油资源的分布及其开采技术的现关与展望

介绍了世界稠油资源及近年来国内外稠油开采技术的研究与应用情况。稠油开采技术包括热采（蒸汽吞吐、蒸汽驱、火驱、SAGD、FAST、SAGP等）和冷采技术（碱驱、聚合物驱、碱加聚合物驱、化学吞吐、露天开采、螺杆泵携砂开采等）。应根据油藏的具体情况,针对性地开展稠油热采和冷采技术,并加强国际间的交流与合作。     

辽河稠油水热裂解催化及化学强化降黏研究

为确保稠油就地水热裂解降黏技术更好地实施,选取辽河油田齐40、齐108和杜32区块为研究目标,以油藏矿物、硫酸镍、环烷酸镍和甲酸供氢剂为催化体系,开展了对油藏矿物地质催化性能及其与外加化学剂协同催化作用的实验研究。实验结果表明,油藏矿物可催化稠油水热裂解反应,并可与催化剂协同催化稠油水热裂解。矿物组成不同,其协同效果不同。油砂矿物存在时,环烷酸镍与硫酸镍结合使用后的催化效果更强,并可节省环烷酸镍用量。甲酸供氢剂的加入可进一步强化稠油水热裂解反应。