稠油油藏胶质沥青质分散技术

为解决稠油开采过程中胶质沥青质析出堵塞储层的问题,进行了稠油油藏胶质沥青质分散解堵技术研究,研制成功了稠油油藏胶质沥青质分散解堵剂.该分散剂具有极强的溶解、分散稠油中的胶质沥青质及杂环芳烃能力和抗凝固防沉降能力,在10℃低温下系统仍不会分层.注汽过程中能防止胶质沥青质沉积,疏通液体流动通道,大幅度降低注汽压力;同时可有效降低稠油黏度,提高原油在低温下的流动性,改善稠油、超稠油在井筒的举升能力及地面的集输效果.     

胶质对沥青质稳定性的影响

为了进一步研究胶质与沥青质之间的相互作用对沥青质稳定性的影响,在分析表征沥青质和胶质的平均结构单元并计算溶解度参数的基础上,向沥青质模型油（沉积物计为AS沉积物）中分别加入胶质NBR和胶质VRR得到AS+NBR沉积物和AS+VRR沉积物,通过分析沉积物颗粒粒径分布,考察胶质对沥青质稳定性的影响程度。结果表明：沥青质的芳香性最强、溶解度参数最大（20.61 MPa1/2）,胶质VRR的芳香性和溶解度参数（17.80 MPa1/2）高于胶质NBR;在沥青质模型油中,随着胶质VRR浓度的增加,沉积物颗粒粒径减小,而胶质NBR的加入并不能使沉积物颗粒粒径变小,当其质量浓度达到1 000 mg/L时,沉积物颗粒粒径反而增加。3种沉积物的热重、凝胶渗透色谱（GPC）和X射线衍射（XRD）分析结果表明：胶质与沥青质之间存在缔合作用,使沉积物芳香片层厚度和直径减小、层间距增大,芳香片层数减小;3种沉积物的相对分子质量从大到小的顺序为AS沉积物＞AS+NBR沉积物＞AS+VRR沉积物。因此芳香性强、溶解度参数接近沥青质的胶质VRR能更好地分散稳定沥青质,使得沉积物颗粒粒径变小、石墨化程度减弱,从而不易沉积和结焦。     

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。     

胶质对沥青质沉积影响研究进展

沥青质沉积会降低油藏润湿率,造成输油管道堵塞,严重影响原油开采。原油中的胶质对沥青质沉积有重要影响。其作用效果与胶质浓度、胶质分子结构及极性有关。本文从胶质的结构与性质,胶质对沥青质沉积的抑制作用和促进作用等方面介绍胶质对沥青质沉积影响的研究进展。     

油井中胶质沥青质沉积结垢的防治

对配制的不同配方的解堵剂,通过各种性能评价,包括腐蚀实验和破乳剂的配伍性实验,得到该解堵剂的性能较好,对油井管柱、设备均不会造成腐蚀伤害,并且不会影响原油的后续处理加工。不同配方的解堵剂不仅对塔河油田油井中沥青质堵塞物的产生有较好的抑制作用,而且对已经产生的堵塞物有较好的溶解效果,对效果好的解堵剂进行复配后发现解堵效果有明显改善;另外该解堵剂对原油还有一定的降粘作用,有利于原油的开采输送。     

CO2驱油过程中原油胶质对沥青质沉积的影响

沥青质沉积严重影响油田开发效果,为明确CO_2驱替过程中胶质对于沥青质沉积的影响,本文以不同胶质沥青质质量比的原油模拟液为研究对象,通过微观可视驱替实验,模拟CO_2驱替过程中沥青质沉积现象,确定其组分含量、物性、固相颗粒大小变化,分析胶质对沥青质稳定性的影响。研究结果表明:胶质以圆球状包裹沥青质,对沥青质起着稳定作用;当胶质沥青质质量比从1∶1升至6∶1时,沥青质沉积量、沉积潜力均先增大后减小,黏度则先减小后增大,胶质与沥青质质量比为2∶1时,黏度达到最低,沥青质沉积量、沉积潜力最大。沥青质沉积与胶质含量有关;沥青质胶质间存在一对作用力—吸附力与分散力,沥青质沉积量与这对力的作用效果相关。图16参25     

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。     

渣油加氢处理中沥青质组成和结构的变化研究

利用渣油加氢处理中试装置考察了温度和加氢深度对加氢产物渣油中沥青质组成、结构的影响,结果表明：随温度或加氢深度增加,加氢产物渣油中沥青质含量降低,沥青质中硫、镍、钒含量降低,氮含量呈增加趋势。采用13C-NMR谱和1H-NMR谱,计算了沥青质的平均分子结构参数,结果表明：随着温度的升高,饱和碳分率逐渐下降,芳香碳分率逐渐升高;随着加氢深度增大,饱和碳分率逐渐升高,而芳香碳分率逐渐下降。     

渣油中胶质和沥青质的定量关联分析

利用多元回归法得到了渣油的胶质含量、沥青质含量与其残炭、(镍+钒)含量、硫含量、氮含量的关联关系。结果表明：沥青质含量与残炭和(镍+钒)含量具有较好的定量关联关系;胶质含量与残炭和氮含量的定量关系较明显;利用关联关系得到的胶质含量和沥青质含量与采用RIPP 10—1990《重油四组分的测定氧化铝吸附法》测得的结果较为接近,相关系数大于0.9。     

原油中沥青质的稳定性

对影响原油中沥青质稳定性的不同因素进行了评价。通过对胶质和沥青质组成及结构特点的研究 ,探索了这些特性与沥青质沉积行为之间可能存在的关系。沥青质由含有正庚烷的原油发生沉淀而获得 ,并通过元素分析及分光技术来辨别。低氢 /碳比、高芳香度及高芳香环稠度是存在于不稳定原油中沥青质的主要特征。根据这些结果 ,沥青质的结构特性对其稳定性有很大的影响。实验中还发现 ,投加商品抑制剂 ,原油的稳定性受其组成的影响 ,特别是对高碱基(官能团 )含量的原油 ,可能与抑制剂有效物 (十二烷基苯磺酸 )含量的减少有关。基于这些发现 ,给出了一些对油田生产适用的建议     

Cracking of Maya Crude Asphaltenes

Cracking of Maya crude asphaltenes was carried out in a batch reactor at the following reaction conditions: temperature of 380–410°C, total pressure of 2 MPa, and asphaltenes/catalyst ratio of 5 g/g using NiMo commercial catalyst. n-hexadecane was used to keep asphaltenes dispersed and reaction time ranged from 0 to 60 min. The products were lumped into four fractions: asphaltenes, maltenes, gases, and coke. A kinetic model assuming pseudo–first-order parallel reactions was used to fit the experimental data.     

孤岛原油正庚烷和正戊烷沥青质乳化能力研究

从孤岛原油中分离出正戊烷和正庚烷沥青质，元素分析和红外光谱分析结果表明，相对分子质量较大的正庚烷沥青质，含杂原子和极性基团较多。将两种沥青质溶于甲苯配制的模型油，分别与蒸馏水、模拟地层水、0～900mg／LHPAM溶液、0～500mg／L黏土液按1：10体积比充分乳化，测定静置时水相（水包油乳状液）透光率，据以考察沥青质的乳化能力，结果表明：正庚烷沥青质的乳化能力强于正戊烷沥青质；矿化离子使沥青质的乳化能力减弱；随聚合物浓度增大，沥青质乳化能力增强；黏土在浓度小于200mg／L时使乳化能力减弱，浓度大于200mg／L时使乳化能力增强。模型油与HPAM溶液间的界面张力，在聚合物浓度100mg／L时有最小值，在500mg／L时有最大值，正庚烷沥青质模型油的界面张力随聚合物浓度的变化较剧烈。正庚烷模型油在聚合物溶液中的乳化油滴直径分布范围较正戊烷模型油窄，聚合物浓度较大时，油滴直径分布范围较宽。正庚烷沥青质模型油与黏土液闸的界面张力，在黏土液浓度增至300mg／L时略有升高，浓度继续增大时大幅升高，而正戊烷模型油的界面张力在黏土液浓度300mg／L时有最低值。图9表3参7。     

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.     

采用核磁共振方法表征重质油结构

采用700 MHz高场核磁谱仪建立了由核磁共振波谱(NMR)获取重质油H、C原子分布与结构参数的分子结构表征方法。以减压馏分油(VGO)和减压渣油(VR)为研究对象,对13C NMR实验条件进行优化, 并考察了1H NMR 和13C NMR实验重复性和准确性。结果表明,较优的13C NMR实验条件是样品质量分数为100%、30°脉冲倾倒角下的延迟时间为50 s;1H NMR和13C NMR实验的6次重复实验的实验标准差分别为086%、136%,1H NMR和13C NMR实验测定重质油中H、C原子分布的准确性误差均在±10%以内。     

Modeling of Coprecipitation of Resin and Asphaltene in Crude Oil by Association Equation of State

Abstract

Resin content is an effective parameter that has adverse effect on precipitation of asphaltene in crude oil. Fluctuations in temperature, pressure, or oil composition disturb the chemical equilibrium in a reservoir, which results in coprecipitation of resin and asphaltene. In this work, coprecipitation of resin and asphaltene has been modeled using an association equation of state (AEOS) in which asphaltene and resin are considered associate components of oil. According to association fluid theory, the total compressibility factor is assumed to be the sum of physical and chemical compressibility factors. Liquid–liquid and liquid–vapor equilibrium calculations are accomplished with the assumption that asphaltene and resin do not contribute in the vapor phase. Comparison of experimental asphaltene precipitation with that obtained from the model developed proves the acceptability of the proposed model.     

原油族组分的分离及检测方法

比较了SY/T5119—2008方法、原油族组分柱色谱分离常规方法和EPA3611方法等柱色谱法对原油族组分的分离效果;并在EPA3611方法的基础上,建立了一种新型原油族组分柱色谱分离方法(简称改良方法),改良方法以较少氧化铝为固定相,以正己烷、正己烷与二氯甲烷混合溶剂(体积比3∶1)、无水乙醇为洗脱液分别洗脱出原油中饱和烃、芳烃、胶质组分,达到较好分离原油族组分的目的。同时建立了TLC/FID评价原油族组分柱色谱分离效果的方法。用TLC/FID技术评价了4种柱色谱法分离原油族组分的效果。实验结果表明,较其他3种方法相比,改良方法的分离效果好、溶剂用量少、分析时间短、操作简便;同时,TLC/FID技术可一次性检测柱色谱分离的4种族组分,具有快速、微量等特点,可用于原油族组分柱色谱分离效果的监测。     

The Effect of Ionic Surfactants on the Electrokinetic Behavior of Asphaltene from a Maya Mexican Oil

Abstract

In this work we show the behavior of the zeta potential of asphaltene when different concentrations of two cationic surfactants (cetylpyridinium chloride and dodecylamine hydrochloride) and one anionic surfactant (sodium dodecyl sulfate) interact with asphaltene particles at different pHs in the aqueous phase. By changing the concentration of cetylpyridinium chloride, dodecylamine hydrochloride, and sodium dodecyl sulfate from 0.01 to 1 mM, we were able to reverse and control the sign of the zeta potential of asphaltene, demonstrating the presence of both electrostatic and hydrophobic interactions at the asphaltene surface.     

不同极性的乙烯-醋酸乙烯酯共聚物对原油中沥青质分散稳定性的影响

以储罐储存的阿曼原油及不同醋酸乙烯酯基团(VA)含量的乙烯-醋酸乙烯酯共聚物(EVA)为研究对象,通过实验研究了添加EVA前后原油中沥青质的动态稳定性、离心稳定性及粒度分布的变化,进而探讨了在相同相对分子质量的情况下,VA基团含量对EVA分散稳定沥青质作用的影响。结果表明,VA基团质量分数为30%的EVA分散稳定沥青质的作用最强;EVA通过吸附于沥青质表面,抑制沥青质絮凝沉淀,从而起到分散稳定沥青质的作用;非极性基团的空间阻碍作用和EVA与沥青质间的吸附作用共同影响了EVA分散稳定沥青质的效果;增加VA含量会导致EVA中非极性链的数量和长度减小,减弱EVA非极性链的空间阻碍作用,从而减弱EVA分散稳定沥青质的效果。分子动力学模拟表明,增加VA含量会增强EVA与沥青质的吸附作用,从而提高EVA分散稳定沥青质的效果。     

The Effect of Solvent Washing on Asphaltenes and Their Characterization

Asphaltenes from an atmospheric residue of heavy crude were precipitated with n-heptane. Part of the isolated asphaltenes was washed under Soxhlet reflux to remove adsorbed maltenes. Comparison among washed and unwashed asphaltenes was carried out and both samples were characterized by atomic absorption, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and differential scanning calorimetry.     

Variation in Composition of Subfractions of Petroleum Asphaltenes

Boscan asphaltenes were precipitated from the crude oil using mixtures of toluene and heptane at temperatures of 24, 50, and 80°C. Another process of extracting solid n-heptane asphaltenes (24°C) using the same solvent systems and temperatures was also investigated. Asphaltene yield is different by the two processes at similar conditions although both increases in temperature or toluene content lead to lower solid yield. This way the asphaltene continuum was investigated from incipient flocculation to total n-heptane precipitated asphaltenes. The asphaltenes were analyzed using elemental analysis, fluorescence spectroscopy, vapor pressure osmometry, and HPLC size exclusion chromatography. The distribution of porphyrins was also measured using absor-bance spectroscopy. The asphaltenes were found to follow a regular trend in elemental ratios, H/C and N/C, indicating increased aromaticity and nitrogen content as the solid yield decreases. Also the molecular weight was seen to increase. Size exclusion chro-matograms and fluorescence spectra were found to be different comparing solids from the two separation processes. This indicates that the asphaltene fractions obtained by extraction of solid asphaltenes are altered relative to asphaltenes obtained by ordinary precipitation. The porphyrin concentration was found to diminish rapidly with solid yield decrease in both precipitation and extraction experiments, the latter fractions, however, containing significantly less asphaltenes indicating an adsorption step in the coprecipitation of porphyrins. Soluble fractions were found to exhibit relatively low molecular weights and an apparent lack of indications of association up to a point of solubles exceeding 50 % of the total asphaltenes. The-latter have implications for the further understanding and experimental investigation. of the associating nature of asphaltenes such as concentration effects during analytical characterization.