大庆原油中活性物质对界面张力的影响

通过预接触时间、红外谱图分析等手段研究了原油中活性物质对复合体系界面张力的影响.结果表明,随着预接触时间的增加,原油与复合体系的界面张力最低值逐渐上升,最终与平衡值相同;而直馏煤油与复合体系的界面张力最低值和平衡值几乎相等,且不受接触时问影响;原油中的活性物质由油水界面向水相扩散并最终达到平衡,并且界面张力在达到最低值前后均与t-1/2(t为实验时间)成线性关系,符合扩散规律;对油相和水相进行红外谱图和质谱分析后发现,在与碱接触后,油相的活性物质减少,水相中活性物质增加,验证了原油中的活性物质对降低界面张力起到重要作用.     

陈庄原油超低界面张力驱油体系研究

开展了单一表面活性剂体系、表面活性剂复配体系及碱+表面活性剂体系与陈庄原油间动态界面张力的测定实验。实验结果表明:CBET-13在较宽的质量分数范围内(0.05%～0.15%)可以使油水界面张力达到超低;质量比为4∶1的SLPS与KAS复配体系,当总质量分数在0.075%～0.15%的范围内可以使油水界面张力平衡值降至10-4 mN/m数量级;总有效质量分数为0.1%、质量比在(9∶1)～(6∶4)范围内的CBET-13与CBET-17复配体系使油水界面张力降到超低;0.2%NaOH+((0.05%～0.2%)SLPS、(0.025%～0.05%)AS-0-4、(0.01%～0.075%)AS-3-0、(0.03%～0.09%)HSBET-12)体系可以使油水界面张力降至10-3 mN/m以下。以上体系,可以作为陈庄油田超低界面张力驱油配方的选择。     

原油组分对化学驱表面活性剂界面张力的影响

为提高化学驱油技术的使用效率,有效掌握表面活性剂的界面张力变化因素,开展了原油组分对表面活性剂界面张力的影响研究。应用原油分离提纯技术、GC-MS、红外光谱和核磁共振分析方法,从原油中分离出石油酸,分析其组分间的相互关系,总结界面张力变化规律。实验结果表明,原油组分中石油酸是影响界面张力的主要成分,其中异构脂肪酸是降低界面张力的重要贡献者。     

Evaluation of interfacial tension between ASP solution and crude oil from B oil field

The interfacial tension (IFT) between alkali-surfactant-polymer (ASP) solution and crude oil is an important parameter for evaluating the feasibility of the ASP flooding for an oil field. The IFT between six series of ASP solution and crude oil from B oil field were measured at 65°C. Each series of ASP solution was composed of NaOH or Na₂CO₃, one of the three kinds of surfactants (S1, S2, and S3), and polymer FT60. The concentration of FT60 and surfactant were 1500 and 2000 mg/L, respectively. The research results show that the IFT between ASP solution and crude oil is ultra-low in the NaOH-FT60-S2 series and NaOH-FT60-S3 series and the best concentration of NaOH is 4000 mg/L and 8000 mg/L, respectively. NaOH-FT60-S2 series is more suitable for B oil field. The IFT between ASP solution and crude oil is ultra-low in the Na₂CO₃-FT60-S2 series and the best concentration of Na₂CO₃ is 4000 mg/L.     

The effect of temperature on the interfacial tension between crude oil and ethoxylated nonylphenols

In this study, the effect of temperature on interfacial tension between crude oil and ethoxylated nonylphenols, with ethoxy group numbers of 4 and 9, was investigated. The interfacial tension was measured using the rising drop technique. Above the critical micelle concentration, the interfacial tension passed through a minimum when the temperature increased. Below the critical micelle concentration, the interfacial tension and time needed to reach equilibrium interfacial tension was reduced when the temperature increased. For a mixture of a two-surfactant system, interfacial tension was not sensitive to the temperature because of formation of mixed micellar aggregates.     

工业木素磺酸盐与大庆原油形成低界面张力的条件研究

系统地研究了工业木素磺酸盐与大庆原油形成低界面张力的条件。研究证明 ,单纯工业木素磺酸盐不能与大庆原油形成超低界面张力 ,但与多种活性剂能产生协同效应 ,添加少量石油磺酸盐、碱为助剂配制的工业木素磺酸盐三元复合体系与大庆原油间的界面张力可以达到 10 -3 mN/m～ 10 -4 mN/m数量级。     

动态界面张力特征及影响因素研究

采用旋转滴界面张力仪，研究了三元复合驱油体系中影响界面张力的有关因素，建立了界面反应模型，并提出了表征该驱油体系特征的浓度窗口和时间窗口等界面参数。结果表明，碱浓度影响动态界面张力的初始值、最低值以及时间窗口，最佳动态界面张力与表面活性剂组成及油相组成有重要的关系。     

用界面张力法测定CO2与原油的最小混相压力

采用悬滴法,测定了在模拟地层温度为356.5K、压力为8.54~23.43MPa时的CO₂与原油间的界面张力.实验发现,CO₂与原油间的界面张力随压力的增加近似呈线性下降趋势.对该数据进行了线性回归,并用外推法计算出当界面张力为零时的最小混相压力为24.17MPa,与实验观测达到一次接触混相状态时的压力(23.43MPa)相比,相对误差为3.16%.采用界面张力确定CO₂与原油间的最小混相压力,既可通过直接观测接触混相状态确定,也可利用所测界面张力数据进行估算,操作简单易行,且耗时少.     

Effect of salinity on the IFT between aqueous surfactant solution and crude oil

The effect of salts and different surfactants on the equilibrium as well as dynamic interfacial tension (DIFT) between crude oil and water was investigated. Three different types of surfactants with identical hydrophobic chain length C₁₂: Sodium Lauryl Ether Sulphate (SLES), Dodecyl Trimethyl Ammonium Bromide (DTAB), Polyoxyethylene (23) lauryl ether (C₁₂E₂₃) were used in this study. SLES shows better synergism of salt and surfactant mixture amongst the surfactants studied. The order of synergism of salts with the surfactant observed was MgCl₂>CaCl₂> NaCl. The results obtained from partition coefficient study show that the addition of salts favours the partition of surfactants into the oil phase hence reduce IFT more effectively. DIFT results reveal that, salt accelerates the surfactant migration towards the interface, hence, reducing the t^* value.     

The influence of oil property on interfacial tension

Abstract

This paper researches the oil property from three different districts in Daqing Oilfield. And then the sulfur contents in crude oil and emulsified oil is tested to explore the dissolution of surfactant into oil phase. Furthermore, the influence of oil property on the interfacial tension and oil displacement effect are studied. Results indicates that, according to the theory that similarities can be solvable easily in each other, the surfactant is likely to enter the crude oil with more heavy components. And thus few of them adsorb at the oil-water interface and the activity reduces. As a result, the interfacial tension increases, which causes the oil displacement effect to become worse.     

复合驱体系化学剂对原油活性组分界面扩张性质的影响

采用小幅低频振荡方法,研究了复合驱体系化学剂如盐、碱、聚合物以及表面活性剂对原油活性组分界面膜扩张黏弹性质的影响和界面扩张模量及相角的变化趋势。研究结果表明,复合驱体系化学剂对原油活性组分界面膜的性质均有一定影响:盐通过改变活性物质在界面上的吸附而影响界面扩张黏弹性质;聚合物能增大低相对分子量活性组分的界面扩张黏度,对高相对分子量活性组分的影响不明显;碱与原油活性组分反应,使扩张黏度明显变化,界面膜的弹性大大增强;表面活性剂能将高相对分子量活性组分从界面上顶替下来,使界面体现为近似单独表面活性剂的性质,而对于低相对分子量活性组分,界面表现为活性组分与表面活性剂混合吸附膜的性质;扩张模量的相角在高工作频率下出现负值。探讨了表观负相角产生的机理。图9表2参7     

复合驱体系化学剂对原油活性组分界面扩张性质的影响

采用小幅低频振荡方法,研究了复合驱体系化学剂如盐、碱、聚合物以及表面活性剂对原油活性组分界面膜扩张黏弹性质的影响和界面扩张模量及相角的变化趋势.研究结果表明,复合驱体系化学剂对原油活性组分界面膜的性质均有一定影响盐通过改变活性物质在界面上的吸附而影响界面扩张黏弹性质;聚合物能增大低相对分子量活性组分的界面扩张黏度,对高相对分子量活性组分的影响不明显;碱与原油活性组分反应,使扩张黏度明显变化,界面膜的弹性大大增强;表面活性剂能将高相对分子量活性组分从界面上顶替下来,使界面体现为近似单独表面活性剂的性质,而对于低相对分子量活性组分,界面表现为活性组分与表面活性剂混合吸附膜的性质;扩张模量的相角在高工作频率下出现负值.探讨了表观负相角产生的机理.图9表2参7     

A correlation between interfacial tension,emulsifying ability and oil displacement efficiency of ASP system for Daqing crude oil

Abstract

Interfacial tension and emulsification are important to enhance oil recovery. There is almost none quantitative research on their correlation for Daqing crude oil. Experiments are performed to find out the correlation between different interfacial tension, emulsification and chemical flooding oil displacement efficiency. The authors changed the structure of surfactant to make characteristics of interfacial tension different significantly and build the relationship between interfacial tension parameters and chemical flooding oil displacement efficiency by physical simulate experiments. The ultralow interfacial tension index (expressed by S) is established by orthogonal test and actual significance of interfacial tension curves. The fitting formula between S and chemical flooding oil displacement efficiency (E) is: E = 0.856 ln(S) + 13.849. The emulsifying ability includes two aspects O/W and W/O. Authors changed the structure of surfactant to make characteristics of ASP systems have similar interfacial property but different emulsification property. Compared the oil displacement efficiency of these systems, built the correlation between emulsifying ability and chemical flooding oil displacement efficiency for Daqing crude oil.

This paper established the index of ultralow interfacial tension and emulsification, and summed up the formulae based on that with oil displacement efficiency. The quantitative evaluation of ASP system can optimize the existing evaluation methods and deepen understandings on flooding mechanism for Daqing crude oil.     

影响旋转滴界面张力测定因素的研究

使用旋转滴界面张力测定仪对长2原油、甲苯、正己烷、环己烷与不同浓度的表面活性剂十二烷基苯磺酸钠(SDBS)和十二烷基磺酸钠(SDS)体系的界面张力进行了测定。讨论了仪器的平衡时间、转速、工作温度等因素对界面张力测量值的影响。同时分析了不同油相对界面张力的影响。结果表明:各体系平衡时间选择在20~30min之间时界面张力测定值准确度较高;在满足L/D≥4的测定要求后继续增大转速会使测量值偏大;仪器工作温度的提高则导致界面张力测定值逐渐减小。     

典型聚合物溶液油水界面扩展黏弹性研究

使用Trackr全自动液滴界面张力仪,研究了聚合物种类和水质对聚合物溶液与十二烷的界面扩展黏弹模量的影响。结果表明,目前广泛使用的聚合物与正十二烷动态界面张力为32~34 mN/m,聚合物溶液与正十二烷形成的界面黏弹膜以弹性为主,相应的弹性模量比黏性模量高3倍以上,配制聚合物溶液水中活性组分和含盐量使聚合物的界面扩展弹性模量降低,对聚合物的界面黏性模量影响更复杂。     

基于液相色谱的原油组分分离及界面性能研究北大核心CSCD

目的对原油进行组分分离,结合界面张力测试结果和结构组成特征分析,进行原油不同组分与表面活性剂之间的界面活性研究。方法采用制备液相色谱技术对原油进行组分分离,考查原油及原油不同组分与阴离子表面活性剂磺酸盐和两性离子表面活性剂甜菜碱之间的界面张力变化趋势;采用气相色谱-质谱方法对原油不同组分的主要结构特征进行分析和对比。结果采用疏水型反相色谱填料,梯度洗脱方式,制备色谱可以将原油分离为6种结构组成差异较大的不同组分;以重烷基苯磺酸盐为表面活性剂时,不含芳烃的4种组分可产生超低界面张力(<1.0×10^(-3)mN/m),含少量芳烃的一种组分接近超低界面张力(~1.0×10^(-3)mN/m);以硫代甜菜碱-12为表面活性剂时,富含芳烃的一种组分可产生超低界面张力(<1.0×10^(-3)mN/m)。结论表面活性剂结构类型不同,产生超低界面张力对应的原油组分亦不同,原油组分与表面活性剂之间的界面活性关系较为复杂。     

钙镁离子影响原油与ASP驱配方产生超低界面张力的机理

钙镁离子能使ＡＳＰ复合驱配方与原油产生的超低界面张力大幅度升高,主要是因为体系中生成了ＣａＲ２、ＭｇＲ２分子。但当ＣａＲ２、ＭｇＲ２转变成ＣａＣＯ３、Ｍｇ（ＯＨ）２沉淀后,ＡＳＰ配方体系与原油间界面张力仍能降至超低     

高温高压条件下CO2 / 原油和N2 / 原油的界面张力

在油藏温度下,采用ADSA（axisymmetric drop shape analysis）技术测定了不同压力下CO₂/原油和N₂/原油体系的平衡界面张力。实验发现,原油与超临界CO₂接触的初始阶段存在强烈的扩散作用,原油中的轻质组分被超临界CO₂溶解抽提,并且随着压力的增加,这种溶解抽提作用增强;原油与N₂接触时,也存在相互扩散作用,但在本实验所测试的压力范围内（小于36 MPa）并不明显。两种体系的平衡界面张力随着压力的升高逐渐降低,其中CO₂/原油体系的平衡界面张力降低的幅度明显大于N₂/原油体系;N₂/原油体系的平衡界面张力随压力基本呈线性变化。在CO₂/原油体系中,当压力低于17.7MPa时,平衡界面张力下降非常快;当压力大于17. MPa时,CO₂/原油体系的平衡界面张力下降较慢。     

聚合物类型对油水界面性质影响研究

采用平面张力仪和表面粘弹性仪研究了部分水解聚丙烯酰胺（HPAM）和疏水缔合聚合物（HAP）对油水界面性质的影响研究结果表明,疏水缔合聚合物HAP可以显著降低煤油／模拟水体系界面张力,但对模拟油／模拟水体系界面张力影响较小;部分水解聚丙烯酰胺类聚合物CA对煤油／模拟水和模拟油／模拟水体系界面张力无明显影响。无论是煤油／模拟水体系还是模拟油／模拟水体系．随聚合物溶液浓度的增加,部分水解聚丙烯酰胺类聚合物CA均使体系界面剪切粘度逐渐增大。而疏水缔合聚合物HAP均使体系的界面剪切粘度先增加,后降低,而后再增加。部分水解聚丙烯酰胺（HPAM）相对分子质量较大时,HPAM溶液／模拟油体系的界面剪切粘度较大。     

乙醇胺与胜坨油田坨28 区块原油活性组分 相互作用对动态界面张力的影响

为明确胜坨油田坨28区块原油中活性组分与有机碱乙醇胺间的相互作用对动态界面张力的影响,采用SARA四组分分离方法对坨28区块原油进行分离,获得饱和分、芳香分、胶质和沥青质等组分;利用醇碱萃取法获得酸性组分;通过旋转滴界面张力仪测定了乙醇胺与坨28区块原油活性组分模拟油间的动态界面张力。研究结果表明:酸性组分是原油的主要活性组分,其质量分数及结构对有机碱与原油间界面张力的行为具有关键性影响,体系动态界面张力的最低值可达10-2m N/m数量级;酸性组分质量分数越大,低界面张力维持时间越长。对于坨28区块原油,与乙醇胺作用的难易顺序为:酸性组分最强,胶质次之,沥青质、饱和分和芳香分与之作用比较微弱。