Laboratory investigation of inversion of heavy oil emulsions

Laboratory investigations have been undertaken to assess the suitability of heavy oil‐in water emulsions for pipeline transportation. The emulsions contained 65% oil in water and were prepared using polyethoxy nonylphenol surfactants. Two methods were employed for simulating the shear process which accompanies pipeline flow: a bench scale stirred vessel and a rotated pipe toroid. The progress of the emulsions towards inversion, at which point the oil becomes the continuous phase, was followed by measuring the surfactant concentration in the aqueous phase using liquid chromatography. At inversion the surfactant concentration falls below the threshold level required to sustain an oil‐in‐water emulsion. The experiments showed that the lifetime of the emulsion depends upon the initial surfactant dosage, the solids content of the oil, the intensity of shear and the nature of the shear process. Laminar flow was found to be less desirable than turbulent flow.     

Processing oil shales with heavy oil recycle

Recycle of heavy oil (>340 °C) to the retort, in order to crack/coke the oil to lighter fractions, was investigated as a means of producing shale oil of more desirable product slates. Conversion of heavy oil to light oil (<340 °C) by thermal cracking and coking in the absence of and during oil shale retorting was studied using the CSIRO BIRCOS retort. As expected, the conversion by thermal cracking increased as temperature increased, with most of the net oil loss in the form of gas. By contrast, the conversion by coking alone decreased as temperature increased, with coke representing all the net oil loss. Thermal cracking was found not to be a first-order reaction, by showing a reduced conversion of heavy oil with reduced concentration of oil vapour. Retorting Stuart oil shale with heavy oil feeding and simultaneous cracking and coking showed a conversion of 19.1 g per 100 g feed heavy oil to 10.9 g light oil, 2.2 g gas and 6.0 g coke, with a net oil loss of 3.8 g per 100 g shale oil produced. These data were used to generate a set of parameters for a mathematical model which simulated a heavy oil recycle loop.     

可实现稠油降黏的重油裂解剂的制备及性能研究

由硫酸氧钒、纳米SiO_2和尿素合成了一种纳米钒酸催化剂DL,以水配制成纳米催化剂体系,分析了纳米催化剂加量、反应温度、水加量及裂解时间对管道中的稠油黏度影响。结果表明,在36 h、180℃和0.3%催化剂加量下,可使稠油降黏率达到92.3%,远高于普通硫酸钒AC的67.1%。     

稠油、超稠油热采技术研究进展

国内石油领域的主攻方向早已从常规油藏转向非常规油气资源,这其中针对稠油油藏的开发一直是当前的研究重点及难点。针对目前稠油、超稠油提高采收率最为有效的热采技术,综述了近5年稠油热采技术中热能供给方式的发展以及热采驱油方式的现存难点和主攻方向,旨在为稠油热采技术的研究突破提供一定的指导和借鉴,同时也对其未来的发展方向及趋势进行了展望。     

Precipitation of asphaltenes from solvent-diluted heavy oil and thermodynamic properties of solvent-diluted heavy oil solutions

Ratios of n-heptane (hep) to toluene (tol) affect the solubility of the asphaltenes in heavy oil extraction processes. Consequently phase changes and time after mixing n-heptane and heavy oil in toluene are important for understanding produced emulsions. The kinetics of phase change when n-heptane is added to toluene-diluted heavy oils, and the thermodynamic properties of partially deasphalted heavy oils were studied. The methods used were monitoring precipitation in time using light microscopy, quantitative asphaltenes analysis by near infrared spectroscopy, refractive index and densities measurements, and calculated solubility parameters of mixtures. At critical mass ratios of hep/tol from 1.37 to 2.0 in diluted heavy oil the precipitated asphaltene particles were observed under the microscope after lag times from 2 h to instantly. Lag times were longer at low initial oil concentration. The floc growth time decreased as heavy oil concentration in toluene increased. The growth patterns in time appeared as dots to beads (strings) to clusters (fractal-like flocs). Final wt% precipitated asphaltenes vs. mass fraction (hep+tol)/heavy oil followed sigmoidal relationships. Curves showing wt% soluble asphaltenes vs. mass fraction hep/tol after 24 h initially followed the same shape as time zero curves and diverged at the onset ratios of hep/tol. Slope for precipitated asphaltenes vs. solubility parameters curve showed a break at 16.4 MPa^1/2. Linear correlations were established for concentrations of soluble asphaltenes in residual oils and density, for refractive index and density and for refractive index and solubility parameter. The latter correlation was in accordance with Lorenz-Lorentz theory. These equations provided a means by which oil density, refractive index and solubility parameter can be predicted when these measurements are difficult to measure practically.     

重油乳化技术的研究进展

综述了国内外关于重油乳化技术的原理、设备、乳化剂选择及节能效果评价等问题的研究现状,介绍了乳化重油催化裂化方面的应用,分析了当前重油乳化技术中存在的问题,并初步探讨了其发展方向。     

Catalytic deoxygenation of heavy gas oil

The extent of oxygen removal during catalytic hydrotreatment of heavy gas oils depends on the chemical composition of catalysts. Deoxygenation increases with the concentration of MoO₃ up to about 6 wt %. Further increases in the MoO₃ concentration do not appreciably increase oxygen removal. Deoxygenation is also improved by the addition of cobalt and nickel oxides to the molybdate catalysts. Independent acidity measurements on the liquid products suggest the presence of phenols.     

重油催化裂解技术研究进展

重油催化裂解技术以增产乙烯、丙烯等低碳烯烃为主要目标,是重油轻质化的有效手段。对催化裂解技术的研究,催化剂和反应器是其核心。本文综述了重油催化裂解技术中采用的各种催化剂和反应器的研究进展,阐述了不同催化剂的适用条件和不同类型反应器的流体特性,并指出深入研究下行床反应器及开发与之匹配的催化剂将是今后开发重油催化裂解技术最具潜力的研究方向。     

用重残油配制燃料油的研究

利用重残油替代部分蒽油,与沥青配制成合格的燃料油,既扩大了沥青的销路,又降低了配制燃料油的成本。研究过程分为实验室小试与生产中试两部分,通过小试得到最佳配比,中试产品的指标全部符合要求。     

轻质和重质原油氧化特性及其动力学

通过热重/微商热重-差热联用分析手段(TG/DTG-DTA)对比分析了一种轻质油和一种重质油的氧化特性和氧化动力学参数。实验结果表明:重质油和轻质油在常压空气流条件下的氧化反应都可以观察到3个明显的反应区间,分别为低温氧化反应(LTO),燃料沉积(FD)和高温氧化反应(HTO)。DTA曲线显示重质油在低温氧化(LTO)和高温氧化(HTO)反应区间的放热峰热流量均高于轻质油,且在高温氧化反应阶段(HTO)更明显。对比分析TG和DTG曲线发现,重质油开始发生快速热重损失及出现最高质量损失速率的温度均高于轻质油。采用Arrhenius方法和Ingraham-Marrier(I-M)方法计算的重质油的氧化反应活化能(LTO,26.19—26.45 kJ/mol和HTO,150.45—157.11 kJ/mol)均高于轻质油的活化能(LTO,12.33—13.75 kJ/mol和HTO,107.31—122.31 kJ/mol),表明轻质油更容易和氧气发生氧化反应。这表明,相比稠油油藏注空气,轻质油藏注空气技术更容易实现较好的驱油效果。     

重质油分离方法研究进展

综述了重质油分离方法的最新进展,并对不同分离方法的使用和改进情况进行了系统的总结。根据不同的需要,按溶解度、极性、酸碱性、分子体积、分子质量将重质油进行预分离,有利于对于重质油分子组成和结构的深入认识。     

Enhanced heavy oil recovery through interfacial instability: A study of chemical flooding for Brintnell heavy oil

This study is aimed at developing an alkaline/surfactant-enhanced oil recovery process for heavy oil reservoirs with oil viscosities ranging from 1000 to 10,000 mPa s, through the mechanism of interfacial instability. Instead of the oil viscosity being reduced, as in thermal and solvent/gas injection processes, oil is dispersed into and transported through the water phase to production wells.Extensive emulsification tests and oil/water interfacial tension measurements were conducted to screen alkali and surfactant for the oil and the brine samples collected from Brintnell reservoir. The heavy oil/water interfacial tension could be reduced to about 7 × 10⁻² dyn/cm with the addition of a mixture of Na₂CO₃ and NaOH in the formation brine without evident dynamic effect. The oil/water interfacial tension could be further reduced to 1 × 10⁻² dyn/cm when a very low surfactant concentration (0.005-0.03 wt%) was applied to the above alkaline solution. Emulsification tests showed that in situ self-dispersion of the heavy oil into the water phase occurred when a carefully designed chemical solution was applied.A series of 21 flood tests were conducted in sandpacks to evaluate the chemical formulas obtained from screening tests for the oil. Tertiary oil recoveries of about 22-23% IOIP (32-35% ROIP) were obtained for the tests using 0.6 wt% alkaline (weight ratio of Na₂CO₃ to NaOH = 2:1) and 0.045 wt% surfactant solution in the formation brine. The sandpack flood results obtained in this project showed that a synergistic enhancement among the chemicals did occur in the tertiary recovery process through the interfacial instability mechanism.     

重油分子的孔内受限扩散研究进展

随着常规石油资源日趋紧张和原油重质化,重油加氢处理过程越来越受到重视。由于重油分子在催化剂孔道中的受限扩散阻力影响着催化加氢反应速率和催化剂的利用率,因此研究重油分子在催化剂孔道中的内扩散行为及规律对指导加氢催化剂优化设计和加氢催化剂有效利用具有重大意义。本文介绍了重油分子孔内受限扩散研究的膜池法、吸附-扩散法和扩散-反应动力学法,指出相较于膜池法和吸附-扩散法,由扩散-反应动力学法研究所得结果更能反映在反应条件下重油孔内的受限扩散行为及规律,具有更广泛的应用价值;并简述了重油分子孔内扩散受限因子的研究进展,分析了用于重油孔内扩散行为及规律研究的多孔材料,指出孔结构均一的模型催化剂是一种利于扩散研究的理想多孔材料。     

Behaviour of heavy metals in the partial oxidation of heavy fuel oil

The behaviour of heavy metals in the partial oxidation of heavy fuel oils under a pressure of up to 100 bar (10 MPa) has been investigated. The tests were carried out in a 5 MW HP POX (High Pressure Partial Oxidation) test plant, that is operated by the IEC (Department of Energy Process Engineering and Chemical Engineering, TU Bergakademie Freiberg) in cooperation with Lurgi GmbH. In several test campaigns preheated oil with a viscosity of up to 300 cSt (= 300 mm²/s) at the burner inlet has been gasified. The heavy metals nickel Ni, iron Fe and vanadium V occur in heavy residual oils in considerable concentration and may seriously impact the gasification itself and the synthesis gas conditioning and usage. While iron is largely recovered in the gasification residue, the recovery rates of nickel and vanadium depend on the process conditions. Volatile nickel compounds were detected in the raw synthesis gas. It was found that an incomplete carbon conversion enables the capture of nickel Ni and vanadium V in the solid residue phase and can thus mitigate the problem of volatile metal compounds in the raw synthesis gas.     

国内重油催化裂化催化剂工业应用现状

介绍了国内典型重油催化裂化催化剂工业应用现状。分别阐述高掺渣比催化剂、抗重金属型催化剂、增产低碳烯烃催化剂和加工M-100专用CORH、CMO催化剂的使用情况,并对各催化剂的性能进行了综合比较,指出不同催化剂所适用原料的特性,最后提出了新型重油催化裂化催化剂的发展趋势。     

委内瑞拉奥里超稠油减黏工艺研究

进行了不同反应温度和反应时间的减黏裂化反应,确定了高温短时间和低温长时间2种反应的较佳反应条件,分别为:415℃/30min,390℃/2 h.并考察了反应的牛焦率及产物的黏度、收率、四组分含量、残炭、凝点、闪点及胶质和沥青质结构.结果表明,委内瑞拉奥里超稠油可以采用减黏裂化工艺进行降黏,并使产物满足380~#燃料油黏度标准.减黏反应的温度和时间是瓦补的,减黏反应进行的深度是反应温度和反应时间共同作用的结果.较高的反应苛刻度使得减黏产物成为非牛顿流体,呈现假塑性流体形态,且有屈服值,对船运可能造成一定的影响.因此,减黏反应的条件要严格控制.高温反应产物的胶质和沥青质的缩合程度较高,同时结构单元中的芳环数也较多,进一步生成生焦前驱物的趋势较强.最终确定委内瑞拉奥里常渣减黏裂化的最佳反应条件为:390℃/2 h.     

我国重质原油典型加工工艺及其发展趋势

本文综述了国内重质油典型加工工艺和发展趋势,着重介绍了几种重质油加工组合工艺的特点和应用,与其单一工艺相比,组合工艺的生产灵活性高,产品品种多,品质好,市场适应能力强     

Steam fingering at the edge of a steam chamber in a heavy oil reservoir

The steam‐assisted gravity drainage (SAGD) process is one of the key in situ recovery processes being used today to recover heavy oil and bitumen. In this process, steam injected through a horizontal well, flows convectively towards the outer edges of a depletion chamber. At the edges of the depletion chamber, the steam releases its latent heat to the cool oil sand and raises its temperature. The heated oil is mobile and flows under the action of gravity to a horizontal production well located several metres below the injection well. It remains unclear what is the exact mechanism of chamber growth. Some have suggested that in addition to heat conduction, it is by convective steam flow in the form of pointed fingers at the edges of the chamber which penetrate the oil sand. In theory published by Butler [Butler, J. Can. Petroleum Technol. 1987;26(3):70–75], it was determined that the fingers can be as long as 6 m for Athabasca bitumen reservoirs. In this research, a new theory is derived and provides predictions of the rise rate which compare better to estimates derived from field thermocouple data and physical model experimental observations than values obtained from Butler's theory. The results suggest that in the absence of mobile water, heat conduction rather than steam fingers at the chamber edge is the dominant heat transfer mechanism.     

重油罐大修的实践与体会

论述了重油罐大修过程中罐内的清理和更新蒸汽加热排管的方法、步聚及注意事项。     

浅谈重油的燃烧装置

陶瓷行业是传统的高耗能行业,燃料的消耗占产品成本的50%以上.笔者由制约能耗的瓶颈--油枪人手,对重油燃枪的工作原理和日常维护做一剖析,希望能够起到抛砖引玉的效果.