沥青质的溶解度对油包水乳状液稳定性的影响

在原油的生产和加工过程中存在乳状液和泡沫溶液稳定性的问题 ,而这一问题在过去的几十年里一直未能解决。由于对乳状液稳定性的微观成因认识不够 ,同时对影响乳状液的过程参数缺乏了解 ,确实可行的破乳方法发展很慢。研究表明 ,焦质和沥青质对乳状液的稳定性有重要作用 ,焦质和沥青质在油水界面间形成薄膜。由此得出 ,油水界面的薄膜和乳状液稳定性与原油中的芳香烃、沥焦比、极性功能团浓度等参数密切相关。本文给出了抑制稳定的原油乳状液形成的简便的物理和化学方法 :原油的调配混合和改变乳状液水相pH值的方法     

油包水乳状液电导率与电破乳研究

通过水滴在电场中所受偶极力的表达式,讨论了W/O乳状液的电破乳机理及介电常数、电导率.借助乳化剂Span80,由50号白油、52号基础油、胜利孤岛原油和蒸馏水制备了含水10%、20%、30%的W/O乳状液,测定了乳状液30℃时的介电常数和黏度.在板电极长宽(cm)8×15、板间距2 cm的电破乳实验装置上,测定了实验W/O乳状液的油水分离效率与板间电压(2～9 kV)、电场作用时间(30、60、120 s)、沉降时间(5～20 s,30℃)的关系,结果如下.在相同实验条件下,含水10%的白油、基础油、孤岛原油乳状液的黏度、电导率和油水分离效率均依次增大;含水30%的白油乳状液在电场中被击穿;白油、基础油乳状液的分离效率随含水率增大而下降,随板问电压增大而上升;含水丰20%的基础油乳状液的分离效率随电场作用时间和沉降时间的延长而上升.讨论了所得结果.图5表1参5.     

原油乳状液的稳定与破乳

本文综述了４个问题；（１）原油乳状液中的界面膜，沥青质，胶质，固体颗粒，石蜡对原油乳状液稳定性的影响；（２）乳化剂对原油乳状液破乳的阻碍作用；（３）原油乳状液稳定与破乳的几种模型；（４）有关破乳剂使用的几个问题（水溶性和油溶性破乳剂，破乳剂用量，线型和体型结构的破乳剂）。     

原油乳状液破乳机理及影响因素研究

由于原油乳状液的形成及稳定性的因素复杂,以及影响原油乳状液破乳的因素众多,因而研究原油乳状液的破乳机理各异,主要有顶替或置换、反相作用、絮凝-聚结、膜排液、膜击破、润湿增溶、反离子作用、褶皱变形机理.又由于原油乳状液的稳定与破乳是一对矛盾,影响乳状液稳定的因素也会影响乳状液的破乳;但从影响破乳剂对原油乳状液破乳的因素来看,主要有原油乳状液的性质、原油破乳剂的性质和外界脱水条件.研究原油乳状液的破乳机理及影响因素,目的是为不同的原油乳状液的破乳方法提供参考依据.     

超声辐照法原油破乳脱水的室内研究

用一台功率1kW的超声波发生器，在声强0．65W／cm^2，频率20kHz，脉冲宽度97ms，间歇比3：1条件下，在55℃将江苏真武含水原油（800mL)辐照10min，静置沉降脱水，同时与自然沉降，化学破乳（破乳剂加量100mg/kg)，化学破乳＋超声辐照破乳等方法作了对比，超声辐照法的初期脱水速率高于化学破乳法，最终（360min)脱水率略高（60．8％对59．4％），化学破乳＋超声辐照法的初期脱水率高于化学破乳法但低于超声辐照法，最终脱水率提高至71．3％，超声辐照法脱出水含量量（17．67mg/L)比自然沉降法（56．32mg/L)，化学破乳法（42．58mg/L)和超声辐照＋化学破乳法（33.97mg/L)均有大幅度降低，与自然沉降法脱出水相比，超声辐照法脱出水中TGB，SRB，铁细菌数分别降低62．0％，52．6％，36．7％，讨论了超声辐照对含水原油破乳 脱水过程的影响。     

浅论影响原油乳状液破乳的因素

从原油乳状液，破乳剂，外界破乳条件三个方面论述了原油乳状液稳定存在的原因及影响破乳的因素，并结合乳状液办面性质分析了好的破乳剂具备扩散吸附性好，润湿能力强，絮凝聚结能力强的性能及外界因素影响破乳的原理。     

原油乳状液稳定性研究：V.北海原油乳状液的稳定与破乳

通过对北海原油乳状液与模型乳状液稳定性的比较研究，发现北海原油乳状液的稳定机理主要是界面膜稳定和立体稳定，即由蜡、胶质、沥青质组分中的界面活性化合物在油水间形成的界面膜和沥青质颗粒、蜡晶及蜡网状结构的作用所致。北海原油乳状液的稳定性与原油的粘度及油水界面张力有关。对北海原油乳状液的破乳应以减弱界面膜强度、消除或减弱蜡晶及蜡网结构的作用为主。本研究所用破乳剂可降低油水界面张力，减弱油水界面膜的强度，     

油包水乳状液中胶质和沥青质的界面剪切黏度和乳状液稳定性的关系

 采用红外和紫外光谱分析了胜利原油中胶质和沥青质的结构，采用界面剪切黏度对其油、水界面膜强度进行了表征，测定了胶质和沥青质模拟油油包水乳状液的稳定性。结果表明，沥青质和胶质的结构和相对分子质量不同，沥青质含有更多的芳环结构，相对分子质量比胶质大，界面膜强度也比胶质强，其乳状液更稳定。     

胶质、沥青质对水-苯乳状液稳定性的影响

为深入研究胶质、沥青质对原油乳状液稳定性的影响,从孤岛渣油中分离出胶质和沥青质,用滴体积法、Ｌａｎｇｍｕｉｒ膜天平、单滴寿命法、瓶试法等研究了它们的水－苯界面活性、Ｌａｎｇｍｕｉｒ膜压,阻止水－苯界面上的水滴向水相融并的能力及稳定水－苯乳状液的能力。结果表明,胶质比沥青质具有更强的水－苯界面活性;沥青质比胶质具有更大的Ｌａｎｇｍｕｉｒ膜压;沥青质阻止水－苯界面上的水滴向水相融并的能力远大于胶质;沥     

沥青质和环烷酸含量对原油乳状液稳定性影响

以大庆油田原油为研究对象,与环烷酸、室内模拟污水配制成不同的原油乳状液.通过对各体系的析水率、界面张力和稳定性指数(TSI)的测试,考察了沥青质和环烷酸共同作用对乳状液稳定性的影响.结果表明,随着沥青质和环烷酸质量分数增大,乳状液的析水率从56.0％增加至93.8％;界面张力从0.984 mN/m增加至9.702 mN...     

Demulsification of dilute O/W emulsion by DC electric field

In this article, the effect of demulsification of dilute O/W emulsion in DC electric field and its mechanism are investigated. The results show that the demulsification process of dilute O/W emulsion is divided into three stages: water layer formation, re-emulsification with transverse diffusion and uplift-stabilization of O/W emulsion. There is a critical current in the electro-demulsification of dilute O/W emulsion. Some evidences confirm that O/W emulsion system with surfactant produces a surface tension gradient in the height direction during the stratification process. The critical current together with the surface tension gradient causes different demulsification processes and current variation for different emulsions.     

Relaxation models for analyzing NMR T2 spectra of O/W and W/O/W emulsions

Abstract

This study aimed at comprehending the transversal relaxation time(T₂) spectra and relaxation mechanism for O/W and W/O/W emulsions in NMR CPMG experiment. The T₂ relaxation model for O/W and W/O/W emulsions was established respectively. T₂ spectra of O/W emulsions with different water content and W/O/W emulsions with settling time in demulsification were analyzed based the relaxation models. The results show that the T₂ spectra characteristics of emulsions in NMR CPMG experiment are consistent with the prediction of relaxation models, which indicated that relaxation models were practical and contribute to the analysis of T₂ spectra for emulsions. Those study laid a foundation for analyzing the characters of single or double emulsions basing T₂ spectra.     

The Preparation of Wax Emulsions Stabilized by C5 Petroleum Resin

Wax emulsions were prepared by using paraffin wax and oxidized wax as raw materials, compound Wb-L as emulsifier, and C₅ petroleum resin as stabilizer. Its performance was studied. The results showed that when M _{C5 petroleum resin r}/M _{wax and oxidized wax} = 0.20, M _emulsifier/M _{wax and oxidized wax} = 0.50, M _water/M _{wax and oxidized wax} = 2.50, emulsifying time was 30 min, emulsifying temperature was 90–95°C, and stirring speed was 1,100 r/min, wax emulsions with good stability, dispersibility, and monodisperse particle size were obtained, giving a preservative solution in pencil board production.     

W/O乳化酸体系稳定性实验研究

从多个角度对柴油-盐酸形成的W/O型乳液体系的稳定性进行实验研究,结果表明:当乳化剂的亲油基中引入双键、长度变短、支链结构增多时,乳化酸体系的稳定性会下降;随着酸内相体积分数的增加,乳化酸粘度随之增加,乳化酸的稳定性增强;在高温条件下,密度调节剂会降低乳化酸的稳定性,与玻尔兹曼理论相悖;乳化酸的稳定性还取决于整个体系分散特性,使用脂肪醇增效剂、增加搅拌速度能减小乳液液滴的平均尺寸,增加乳化酸体系的稳定性。     

TG法测W/O乳化液中的含水量

建立了取样量小 ,操作方便 ,用热重法分析油包水型乳化液中含水量的方法。使用废润滑油乳化液样品进行试验 ,采用低升温速率 2℃ /min ,在质量变化微分曲线的最低点处读取数据 ,热重法分析结果与ASTMD12 3-92标准方法的分析结果非常吻合 ,最大相对误差小于 5 %。对比乳化液和油水简单混合物的热重法分析结果 ,还可得到乳化液类型和粒径分布等信息。     

W／O型聚丙烯酰胺胶乳减阻性能的研究

研究了Ｗ／Ｏ型聚丙烯酰胺（ＰＡＭ）胶乳在水中的凉阻性能。探讨了聚合物合子量、聚合物溶液浓度、溶液ｐＨ值、流速等对减阻性能的影响。发现Ｗ／Ｏ型聚丙烯酰胺具有良好的减阻性能，在相同流量下，ＰＡＭ水溶位的流动阻力明显小于清水流动阻力。在一定浓度范围内，随ＰＡＭ浓度增加，减阻性能增加。ＰＡＭ的分子量对流动阻力影响较明显，分子量大者减阻性能较高。当溶液ｐＨ值小于７时，减阻性能显著，当ｐＨ值大于７时对减阻影响较少。在相同浓度下，随流速增加，流动阻力减小。     

聚合物对W/O乳状液稳定性的影响规律研究

根据孤岛聚合物驱现场采出液特征,室内模拟配制了W/O乳状液,研究了聚合物对乳状液表观黏度、液滴直径及油水界面黏弹性质的影响规律.结果表明,采出液中的残留聚合物可显著提高乳状液的表观黏度,当聚合物浓度为400 mg/L时,乳状液黏度达到极大值;大于400 mg/L时,乳状液的黏度不再增大.聚合物浓度增大使W/O乳状液的水珠粒径减小、分布集中;聚合物浓度大于300 mg/L时,水珠粒径基本不变.聚合物可改变油水界面膜的流变性,增强油/水界面的黏弹性模量和复数黏度,增大界面膜的强度,增加乳状液的稳定性.以上效应导致含聚合物的采出液乳化更加稳定,破乳更加困难.     

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.     

抗高温水包柴油乳状液研究

针对欠平衡钻井对低密度钻井液的要求,以水包柴油乳状液为研究对象,通过实验优选乳化剂,研究了2种和多种乳化剂协同作用下水包柴油乳状液的稳定性,优选出了抗温性能好、乳化能力强的复合乳化剂,配制出了抗180℃高温的水包油乳状液.     

Influence of Water Content and Temperature on Stability of W/O Crude Oil Emulsion

Water content of W/O crude oil emulsion and temperature have great influence on stability of the W/O crude oil emulsion and the subsequent demulsification process especially for oil-water treatment centers using a two-step sedimentation demulsification process in Jilin oilfield. Electrical microscope and Turbiscan stability analyzer were employed to investigate the influence of water content and temperature on stability of synthetic W/O emulsion. The results show that the average water droplets size decreases when water content decreases, the emulsion stability decreases when water content or holding temperature increases, and the emulsion stability constant and the temperature have a linear relationship.