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1.
重烷基苯磺酸盐的界面性质和驱油机理   总被引:13,自引:0,他引:13  
重烷基苯磺酸盐是在三次采油中广泛采用的表面活性剂之一,但重烷基苯原料组成复杂导致最终磺化产物的驱油效果差异很大.实验通过柱层析的方法将重烷基苯分离成6个族组分,并对其中的二烷基苯、单烷基苯和二烷基茚萘满、烷基萘、多苯烷进行磺化,中和提纯后对各磺酸盐进行界面张力测定.通过对比不同矿化度下界面张力以及各组分复配后的界面张力,对原油等效烷烃数(EACN)以及各组分碳数最低值(nmin)测定,得出各组分之间协同效应的规律和复配机理,从而阐明了重烷基苯磺酸盐的驱油机理.通过研究十二烷基苯磺酸钠(LAS)与各组分之间的复配作用对上述规律和机理进行了进一步验证.  相似文献   

2.
溶致液晶体研究及其在三次采油中的应用   总被引:4,自引:0,他引:4  
研究了石同磺酸盐/正戊醇/水的三元体系和石油磺酸盐/癸烷/正戊醇/水的拟三元体系相图中的液晶区域,揭示了不同组分对液晶区域大小的影响以及液晶的流变性和液晶的结构,在三次采油中,用六角状溶致液晶体系代替三元复合驱体系进行化学驱油,虽然驱油效率更高,但需进一步降低液晶驱油体系的成本。  相似文献   

3.
低浓度的表面活性剂ASP(碱/表面活性剂/聚合物)驱油体系溶液与模拟原油混合,研究该体系的相行为和界面张力的变化情况,并应用粒度分析仪和冷冻蚀刻透射电子显微镜技术,对中间混合层的粒径分布及其结构进行研究.发现中间混合层的体积随各组分的浓度变化而有一定的规律性,中间混合层与油相和水相之间的界面张力均能达到超低.特别是得到了冷冻蚀刻电子显微镜照片, 并提出中间混合层为胶束、微乳液、乳状液等表面活性剂聚集体的共存体系,其中微乳液结构占主要地位.这对丰富表面活性剂的理论研究及探讨三元复合驱的驱油机理必将起到重要作用.  相似文献   

4.
研究了表面活性剂/盐/模拟油体系与表面活性剂/碱/模拟油体系中油酸甲酯与表面活性剂协同效应机理.结果表明两种体系中协同效应机理不同.在盐体系中,油酸甲酯主要通过改变油相的等效烷烃碳数(EACN) 影响表面活性剂在油水相分配.而碱体系中,油酸甲酯影响表面活性剂在油水相分配从而影响界面张力;另一方面,油酸甲酯吸附在界面上顶替表面活性剂分子影响界面张力.对于不同结构表面活性剂,两种作用竞争的结果不同.  相似文献   

5.
表面活性剂亲水-亲油能力对动态界面张力的影响   总被引:3,自引:0,他引:3  
当两个不互溶的液相接触时,如果其中一相或两相含有表面活性物质,就可能产生动态界面张力。两相间的界面张力随时间连续变化,直到平衡为止。在到达平衡的过程中,经常通过一个最低值。酸性油/碱水体系也会出现类似现象。Englind和Berg把动态界面张力解释为表面活性物质在界面上累积的结果,并观察到1,5-戊二醇由白油向水中传质时存在明显的吸附-脱附位垒。Rubin和Radke首次给出了解释酸性原油与碱水溶液接触时产生动态界面张力的物理模型,他们提出在油水上存在一个表面活性物质的脱附位垒,原油中的酸性物质与氢氧化钠在界面上的反应是迅速完成的,而这些物质的脱附,则比较缓慢,从而合理地解释了这一特征。近年来,由于超低界面张力在强化采油中的重要性,国外研究者对酸性油/碱/表面活性剂体系的动态界面张力特征进行了比较系统的研究,但其机理有待进一步探讨,本文通过对正构烷烃/石油磺酸盐体系动态界面张力的研究,考察了吸附-脱附位垒产生的原因、影响因素及其对动态界面张力曲线的影响,对酸性油/表面活性剂体系动态界面张力的机理进行了更深入的探索。  相似文献   

6.
由于纳米流体的界面效应、小尺度特征,在提高采收率领域具有较大应用潜力,但其驱油机理尚待进一步明确.为了进一步研究纳米流体的驱油机理和驱油效率,采用硅基纳米球与表面活性剂耦合的方式研发高活性纳米流体,借助静态宏-介-微观实验和岩心物理模拟,阐明高活性纳米流体形成乳状液的流度控制和介观驱油效率.实验结果表明,高活性纳米流体可降低普通稠油界面张力至10-2 mN·m-1数量级,在油藏含水率饱和度30 ~ 80%条件,高活性纳米流体干预的油水乳化液粘度是原油粘度的1.28 ~4.32倍,表现良好原位流度控制性能;高活性纳米流体与岩心渗透率适应性强,水驱至含水率98%,0.6倍孔隙体积的0.4wt%高活性纳米流体通过原位流度控制,显著提高采收率达25%以上.研究结果深化了纳米流体驱油机理,同时为纳米驱提高采收率提供新路径.  相似文献   

7.
研究了十二烷基硫酸钠(SDS)和甜菜碱(Betaine)以及复配体系在油水界面和气液界面的排布行为,探讨了温度、无机盐和复配比例对表面活性剂界面活性和泡沫稳定性的影响,重点探讨了多价无机阳离子对表面活性剂界面吸附行为和复配协同加合增效作用的影响,得到了海水为介质条件下两方面性能均较好的体系,取得的认识为高盐条件下低张力泡沫驱油体系的设计与应用提供理论依据和指导.  相似文献   

8.
油气混相过程的界面传质特性对气驱提高原油采收率技术非常重要。本文针对吉林某油田的实际油组分,采用分子动力学模拟研究了气驱油过程,分析了不同气体和驱替压力下油气两相的状态变化以及界面特性,获得不同驱替气体的最小混相压力(MMP)。结果表明,随着驱替气体压力的升高,气相的密度逐渐增大,油相膨胀密度降低,气相与油相的混合程度增强,油气两相界面厚度增加,界面张力随之减小。同时发现,驱替相中二氧化碳浓度越高,在同等气体压力下,油气界面更厚,油气混合程度更高。纯CO2驱油得到的MMP远远小于纯N2驱油,当这两种气体摩尔比为1 : 1混合时MMP介于两种纯气体之间,说明要达到同样的驱油效果二氧化碳需要的压力更小。最后,本文从分子微观作用力角度解释了驱替气体不同时影响油气混相程度的机制,通过分子平均作用势曲线发现油相分子对CO2的吸引力要大于N2分子,因此CO2分子更容易与油相混合,驱替效果更明显。  相似文献   

9.
通过阴阳离子表面活性剂复配,在实际油水体系中获得了超低界面张力.通过在阴离子表面活性剂分子结构中加入乙氧基(EO)链段,以及采用阴阳离子加非离子型表面活性剂的三组分策略,有效解决了混合表面活性剂在水溶液中溶解度问题.进而研究了阳离子表面活性剂结构、非离子表面活性剂结构、三者组分配比、表面活性剂总浓度等因素对油水界面张力的影响,从而在胜利油田多个实际油水体系中获得了较大比例范围和较低浓度区域的油水超低界面张力,部分体系甚至达到了10-4 mN·m-1.由于阴阳离子表面活性剂间强烈的静电吸引作用,相关体系具有很好的抗吸附能力.经过石英砂48 h吸附后,体系仍然具有很好的超低界面张力.  相似文献   

10.
乳状液的微观特征影响着油包水乳状液的稳定性,从而影响油基钻井液的稳定性能。室内选用3#白油、26%CaCl2水溶液、JH主辅乳化剂,采用超声分散乳化方法,配制得到油包水型白油乳状液。采用显微图像技术,研究了JH主辅乳化剂加量、油水比、有机土对白油乳状液微观特性的影响;以油水界面张力、动态界面张力以及界面扩张粘弹性等为参数分析了乳状液稳定性的机理。结果表明:JH主辅乳化剂配比为4∶1,加量为4%,油水比为80∶20时,白油乳状液中的分散相呈球形液珠,直径为3.31~12.93μm;油水界面张力为0.559 mN·m-1;JH主辅乳化剂形成的油水界面膜强度大,白油乳状液稳定性好;有机土与JH主辅乳化剂的协同作用使白油乳状液和油基钻井液的稳定性能显著提高。  相似文献   

11.
基于两相分离的乳状液稳定模型,研究了三元复合驱模拟原油乳状液稳定动力学特性;通过液膜强度和油水界面张力探讨了碱/表面活性剂/聚合物对模拟原油乳状液稳定动力学特性的影响机理。结果表明,乳状液稳定模型可以很好的评价乳状液的稳定性,并得到乳状液的稳定动力学特性;碱浓度小于900 mg/L有利于乳状液的稳定,碱浓度大于900 mg/L不利于乳状液的稳定;表面活性剂和聚合物浓度的增加使得形成的模拟原油乳状液更加稳定;模拟原油乳状液的稳定作用主要是通过碱、表面活性剂降低油水界面张力并增加油水界面膜强度,聚合物通过提高界面膜强度实现的,三者存在协同效应。  相似文献   

12.
An experimental study on determination of alkaline, surfactant, polymer (ASP) flooding systems using natural mixed carboxylate was conducted to examine the decisive factor for ASP flooding, phase behavior or interfacial tension. The volume and color of middle phase liquid were observed, the transient interfacial tension at different salt and alkaline concentrations were measured and, finally, coreflood test in laboratory were made. The results showed the flooding system with larger volume and brown color of middle phase emulsion sometimes not to obtain better oil recovery efficiency. The primary and more important phenomenon affecting the oil recovery is a lower or ultralow minimum interfacial tension value at the crude oil/soluble phase interface.  相似文献   

13.
The phase behavior and interfacial tension of alkali/surfactant/polymer (ASP) flooding system and simulative crude oil were investigated, and the size distribution and structure analysis of the middle mixed layer (MML) were also studied by size analyzer and freeze-fracture TEM. It was found that there were some rules between the volume of MML and the concentration of each component, and the interfacial tension between MML and the oil phase or water phase could reach an ultra-low value. Especially, the freeze-fracture TEM micrographs of MML were firstly obtained, and the new viewpoint was put forward that there coexist the structures of micelle, microemulsions and emulsions in MML and the structure of microemulsion is dominant. This would make an important effect on the research of surfactant theory and ASP flooding mechanism.  相似文献   

14.
The effect of surfactants' type and concentration on the interfacial tension and contact angle in the presence of hydrophilic silica particles was investigated. Silica particles have been shown to have an antagonistic effect on interfacial tension and contact angle in the presence of both W/O and O/W surfactants. Silica particles, combined with W/O surfactant, have no effect on interfacial tension, which is only dictated by the surfactant concentration, while they strongly affect interfacial tension when combined with O/W surfactants. At low O/W surfactant, both particles and surfactant are adsorbed at the interface, modifying the interface structure. At higher concentration, interfacial tension is only dictated by the surfactant. By increasing the surfactant concentration, the contact angle that a drop of aqueous phase assumes on a glass substrate placed in oil media decreases or increases depending on whether the surfactant is of W/O or O/W type, respectively. This is due to the modification of the wettability of the glass by the oil or water induced by the surfactants. Regardless of the surfactant's type, the contact angle profile was dictated by both particles and surfactant at low surfactant concentration, whereas it is dictated by the surfactant only at high concentration.  相似文献   

15.
Experimental studies were conducted to explore the fundamental mechanisms of alkali to lower the interfacial tension of oil/heavy alkylbenzene sulfonates (HABS) system. Sodium hydroxide was used as the strong alkali chemical to investigate the interfacial tension (IFT) of oil/HABS system. The influences of salt and alkali on the interfacial activity were studied by the measurement of interfacial tension and partition coefficient. Moreover, the alkali/surfactant solutions were measured by dynamic laser scattering. The results showed that compared with the salt, the function of alkali to lower the interfacial tension and improve partition coefficient is more significant. The micelles formed by surfactants could be disaggregated because of adding alkali, so the size of micelles decreases and the number of mono‐surfactants increases, then more surfactant molecules move to the interface of oil/surfactant system and the adsorption of surfactants at oil‐water interfaces increases, which can lead to the decrease of IFT.  相似文献   

16.
Although alkaline/surfactant/polymer (ASP) flooding is successfully applied in oil fields, some disadvantages such as scales, corrosion effects, and viscosity reductions of polymer solutions appear. Usage of organic alkalis can avoid or decrease these disadvantages. In this paper, the physicochemical properties, including interfacial tension (IFT), and viscosity, of organic alkali combinational flooding solutions and their effectiveness as enhanced oil recovery agents are investigated. Monoethanolamine (MEA) is the optimal one for decreasing the IFT among the three organic alkalis studied in this paper. Although MEA cannot decrease the IFT as low as NaOH does, it has good compatibility with both surfactant and the polymer hydrolyzed polyacrylamide (HPAM). MEA not only helps a surfactant solution or HPAM/surfactant mixture attain ultralow IFT values, but can also promote better viscosity stability for HPAM or HPAM/surfactant solutions compared to NaOH. Moreover, core flood experiments show that adding MEA can obtain additional tertiary oil recovery of 6%–10% original oil in place (OOIP) on the top of HPAM or HPAM/surfactant flooding, although MEA has a lower enhanced oil recovery than NaOH. The experimental results show that MEA is a good choice to replace NaOH in enhancing heavy oil recovery.  相似文献   

17.
Experimental studies are conducted in order to elucidate the mechanisms responsible for synergism/antagonism for lowering interfacial tension in alkyl benzene sulfonate/brine/methyl oleate model oil and alkyl benzene sulfonate/alkali/methyl oleate model oil systems. We found that different mechanisms exist in above two systems. In alkyl benzene sulfonate/brine/methyl oleate model oil systems, methyl oleate influences the partition of added surfactants between oil and aqueous phase by changing equivalent alkane carbon number (EACN) value of model oil. In alkyl benzene sulfonate/alkali/methyl oleate model oil systems, methyl oleate in oil phase has two functions: on the one hand, it influences the partition of surfactant between oil and aqueous phase; on the other hand, it directly affects IFT by displacing surfactant molecule or forming mixed film with surfactant molecule at the interface.  相似文献   

18.
Experimental studies have been conducted to elucidate the mechanisms responsible for synergism/antagonism for lowering dynamic interfacial tension (IFT) in surfactant/alkali/hydrocarbon and surfactant/alkali/acidic model oil systems. Dynamic IFTs between hydrocarbon/acidic model oil and alkali/surfactant solutions were measured. We learned from our experimental results that alkali has the function of decreasing n(min) values of surfactant solutions. The synergism/antagonism for lowering the stable values of dynamic IFTs in surfactant/alkali/hydrocarbon and surfactant/alkali/acidic model oil systems depends on factors that can change the EACN/n(min) value, such as the oleic acid in the oil phase and the n(min) values of surfactant and alkali. A new explanation with respect to EACN/n(min) values is provided.  相似文献   

19.
In the present study, we have performed molecular dynamics simulations to describe the microscopic behaviors of the anionic, nonionic, zwitterion, and gemini surfactants at oil/water interface. The abilities of reducing the interfacial tension and forming the stable interfacial film of the four surfactants have been investigated through evaluating interfacial thickness, interface formation energy and radial distribution function. The results show that the four kinds of surfactants can form in stable oil/water interface of monolayer, and the gemini surfactant can form the more stable monolayer. The results of the above three parameters demonstrate that the gemini surfactant has the best simulation effect in the four surfactants. From the calculated interfacial tension values, the gemini surfactant possess the more powerful ability of reducing the interfacial tension than others, so it is more suitable to be used as the surfactant for flooding. In addition, the effects of different electric field intensities on surfactants were calculated, through the radial distribution function of the hydrophilic group in the surfactant and the oxygen atom in the water. We have found that the adding of the periodic electric field can significantly affect the diffusion behavior of the molecules, and nonionic surfactant has stronger demulsification capability than others.  相似文献   

20.
Alkali and alkali/surfactant displacing agents are designed for two kinds of heavy oil. Results of emulsifying capacity, dynamic interfacial tension (IFT) and water-wet core flooding tests show that, although alkaline/surfactant systems exhibit better capacity in emulsification and IFT reduction, oil recovery values of alkaline/surfactant flooding are lower than those of alkaline flooding. Glass-etched micromodel tests further demonstrate that, when alkaline solution penetrates into the oil phase, water streams break into ganglia coating oil film. Water ganglia may be entrapped by narrow throats, consequently presenting a water-oil alternating slug flow. Similar water ganglia also appears in alkaline/surfactant flooding, however, water channeling along the pore surface occurs subsequently, resulting in its relatively lower oil recovery.  相似文献   

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