首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 250 毫秒
1.
研究了植物油酸及其中和物/Tween-60复配体系与大庆原油间界面张力随各种因素的变化规律,结果表明,当0.40%NaCl存在时,植物油酸中和度为0.85,NaCl浓度为0.90%时,复配以0.10%Tween-60既可使体系兼容,又可使之保持较低界面张力。  相似文献   

2.
借助DTA研究了YbCl3-CaCl2-NaCl三元体系相图,发现该体系有对应于YbCl3、CaCl2,Na3YbCl6的4个液相面,5条二次结晶线,1个三元低共熔点E(87.0%YbCl3,1.0%CaCL2,12.0%NaCL;450℃)和三元转熔点P(61.0%YbCl3,19.0%CaCl2,20.0%NaCl;474℃)。  相似文献   

3.
借助DTA研究了YbCl3-CaCl2-NaCl三元体系相图,发现该体系有对应于YbCl3、CaCl2、NaCl、Na3YbCl6的4个液相面,5条二次结晶线,1个三元低共熔点E(87.0%YbCl3,1.0%CaCl2,12.0%NaCl;450℃)和三元转熔点P(61.0%YbCl3,19.0%CaCl2,20.0%NaC1;474℃)。  相似文献   

4.
钕在含NdCl3体系中溶解损失的研究   总被引:1,自引:0,他引:1  
测定了金属钕在NdCl3-MCln体系、NdCl3-(90.0wt%KCln)(M=Li,Na,K,Ca,Sr,Ba;n=1或2)截面和NdCl3-LiF体系(富NdCl3区)中的溶解损失。发现钕在NdCl3-KCl,NdCl3-CaCl2和NdCl3-(90.0wt%KCl,10.0wt%CaCl2)体系中溶解损失较小,而在NdCl3-KCl体系中随温度的升高而加大,当体系中NdCl3浓度<50  相似文献   

5.
流动注射—胶束荧光法快速测定葡萄糖中的微量铝   总被引:1,自引:0,他引:1  
本提出Al-Calcein-CTMAB-Tween-80体系,用流动注射-胶束荧光法快速测定葡萄糖中微量铝的方法。荧光最大激发波长和发射波长分别为478.0和509.0nm.Al^3+的浓度在0-6μg/mL范围内标准曲线呈线性关系,方法检出下限为8.42×10^-3μ/mL。方法已用于测定葡萄糖中微量铝,相对标准偏差为1%左右,回收率为95-101%,进样频率为140次/h,进样量为0.443  相似文献   

6.
严继民  叶学其 《化学学报》1995,53(9):833-836
本文用量化学及分子力学方法计算了(Na@C60)及(Cl@C60)中Na及Cl与C60之间的相互作用,总的相互作用是吸引。在静电相互作用、色散相互作用及电子云重排斥相互作用三项中前一项占90%以上,有着决定性的影响,色散相互作用约占5%。对电子云重叠排斥作用来说,由于Cl^-的半径比Na^+的大很多,所以在(Cl@C60)中这种作用要比在(Na@C60)中大很多。  相似文献   

7.
左正忠  侯润香 《电化学》1997,3(2):148-154
本文提出了一种电沉积光亮锡钴镜三元合金的新工艺,其溶液组成及操作条件为:Na3C6H5O7.2H2O100-150,Na2EDTA.2H2O20-30,SnCl2.2H2O15-20,CoSO4.7H2O25-35,ZnCl215-20g.L^-1;稳定剂WDZ-1 60-100,光亮剂WDZ-215-20mL.L^-1,pH=4-6,Dk=0.55。0A.dm^-2,T=5-35℃。在此条件下可  相似文献   

8.
描述了一种移动化学反应界面的实验装置,这一装置备有二台恒流泵用于连续性地驱动阴极液和阳极液,备有二根连接于计录仪的电极用于测定反应管两端的电压。用0.005mol.L^-1CoCl2和0.01mol.L^-1NaOH(同时含有0.1mol.L^-1背景电解质(KCl)形成的移动化学反应界面实验了这一装置。结果表明:(1)能很好地避免电解时产生的氢离子和氢氧根离子的干扰;(2)在单根凝胶柱上可进行多  相似文献   

9.
示波极谱测定天然水,食品和生物样品中痕量锡   总被引:1,自引:0,他引:1  
在H2SO4-HClO4-NaBr-(NH4)2VO3的体系中,Sn(Ⅳ)在-0.60V左右产生一个非常灵敏的极谱催化谱,Sn(Ⅳ)浓度在0.8-160ng.mL^-1之间与峰电流成线性关系,检测限为0.26ng.mL^-1。该法应用于天然水、食品和生物样品中痕量锡的测定,结果令人满意。  相似文献   

10.
借助于DTA测定了YbCl3-CaCl2-MgCl2三元体系液相限.发现本体系有对应于YbCl3、CaCl2、MgCl2和不稳定化合物X的四个液相面,五条二次结晶线,一个三元低共熔点E(38.0wt%YbCl3,31.0wt%CaCl2,31.0wt%MgCl2;556℃)和三元转熔点P’(45.5wt%YbCl3,28.0wt%CaCl2,26.5wt%MgCl2;600℃).  相似文献   

11.
油酸-油酸钠水溶液/原油间的瞬时界面张力   总被引:4,自引:0,他引:4  
羧酸盐表面活性剂以其价格低廉、资源丰富和较高的界面活性而受到重视[1].我们将廉价的天然核酸盐复配体系用于提高采收率研究,取得良好效果问.据最近报道问,用瞬时界面张力(l)评价驱油体系更符合实际采油过程.本文应用试剂级油酸,试图从理论上探讨不同因素对混合体系瞬时界面张力的影响规律,为驱油体系配方的选择提供依据.1实验部分1.1试剂油酸(R17C00H),分析纯收京长城化学试剂厂产品).水解聚丙烯酸胶(HPAM),平均分子量为1.7X10’,平均水解度为20%,(美国辉瑞公司产品).1.2方法按设计量在电子分析天平(精…  相似文献   

12.
Time-dependent interfacial tension (IFT) has been investigated for an interfacially reactive immiscible system composed of model-acidified oil and alkaline water. The acidified oil was composed of either lauric acid or linoleic acid dissolved in n-dodecane. Drop volume tensiometry was employed to measure the interfacial tension between the two phases. In the case of lauric acid, the IFT value was found to decrease sharply with increasing alkali concentration, even at low drop formation times. In the case of linoleic acid, the IFT decrease with the drop formation time was more gradual, especially at low alkali concentration. The rate of formation of the interfacial area was also found to be dependent on alkali concentration.  相似文献   

13.
The purpose of this study is to obtain the interaction between heavy oil components and petroleum sulfonate (NPS). In this article, the effects of pH, NaCl concentration, and NPS on the oil–water interfacial tension (IFT) of Gudao crude oil and its polar components were investigated. The results show that the NPS concentration corresponding to turning point of IFT is 0.001 g·mL?1. This is lower than the CMC of NPS (0.0015 g·mL?1) as there is a positive synergetic effect between NPS and the active substances of crude and its components, and the strength of their interaction depends on the interfacial activity of crude components. In simulated system of crude and polar components with 0.1 wt% NPS, at basic condition, the acidic substances in the polar components create naphthenates (the component whose acid number is higher creates more naphthenates), leading to lower IFT, so the interaction between heavy oil components and NPS is stronger in the basic condition. Proper concentration of NaCl in the stimulated systems improved the hydrophile-lipophile balance of emulsifier (NPS), accelerated the well-regulated adsorption of NPS in oil–water interface, and increased the interfacial activity of NPS, the interaction between heavy oil components and NPS was also enhanced.  相似文献   

14.
Betaine surfactants with lipophilic groups of different lengths were synthesized in this research and the dynamic interfacial tension (IFT) between solutions of these surfactants and three kinds of crude oil from Shengli Oilfield are measured. The results indicated that, for Gudao and Gudong heavy oil, cetyl dimethyl hydroxyl sulfobetaine (SBET-16) was the most efficient in lowering the IFT in the case of no alkalis, while for Shengtuo heavy oil, cetyl dimethyl carboxymethyl betaine (CBET-16) was best. SBET-16 with the concentration of 0.003–0.1% and 0.005–0.1% can reduce the oil/water IFT to ultra-low for Gudao and Gudong oil respectively, CBET-16 with the concentration of 0.005–0.1% can lower the oil/water IFT to ultra-low for Shengtuo oil. These results showed that for different oils, an oil displacement agent with high capacity to lower the oil/water interfacial tension may be obtained only by changing the molecular structure of betaine surfactant. This study can be used to guide the design of surfactants for alkaline-free combination flooding.  相似文献   

15.
Alkylnaphthalene sulfonates with high purity were selected as model components to research synergism for lowering interfacial tension (IFT) in surfactant/alkali/acidic oil systems. The dynamic IFTs between alkylnaphthalene sulfonates with different alkyl chain length and n-decane, oleic acid model oil, or Shengli crude oil were measured. The results showed that the alkylnaphthalene sulfonates with different alkyl chain lengths had different synergism with different acidic components and their ionized acids under the same conditions. The synergism for lowering dynamic IFT in alkylnaphthalene sulfonate/alkali/acidic oil systems was controlled by alkylnaphthalene sulfonate concentration, alkyl chain length, alkali concentration, alkali type, and oleic acid concentration: optimal physicochemical conditions were necessary to the best synergism. This indicates that the synergism among added surfactant acidic components in crude oil and their ionized acids is controlled by the ratio of their interfacial concentrations.  相似文献   

16.
Many carbonate oil reservoirs are oil-wet and fractured; waterflood recovery is very low. Dilute surfactant solution injection into the fractures can improve oil production from the matrix by altering the wettability of the rock to a water-wetting state. A 2D, two-phase, multicomponent, finite-volume, fully-implicit numerical simulator calibrated with our laboratory results is used to assess the sensitivity of the process to wettability alteration, IFT reduction, oil viscosity, surfactant diffusivity, matrix block dimensions, and permeability heterogeneity. Capillarity drives the oil production at the early stage, but gravity is the major driving force afterwards. Surfactants which alter the wettability to a water-wet regime give higher recovery rates for higher IFT systems. Surfactants which cannot alter wettability give higher recovery for lower IFT systems. As the wettability alteration increases the rate of oil recovery increases. Recovery rate decreases with permeability significantly for a low tension system, but only mildly for high tension systems. Increasing the block dimensions and increasing oil viscosity decreases the rate of oil recovery and is in accordance with the scaling group for a gravity driven process. Heterogeneous layers in a porous medium can increase or decrease the rate of oil recovery depending on the permeability and the aspect ratio of the matrix block.  相似文献   

17.
Combinatory flooding techniques evolved over the years to mitigate various limitations associated with unitary flooding techniques and to enhance their performance as well. This study investigates the potential of a combination of 1-hexadecyl-3-methyl imidazolium bromide (C16mimBr) and monoethanolamine (ETA) as an alkali–surfactant (AS) formulation for enhanced oil recovery. The study is conducted comparative to a conventional combination of cetyltrimethylammonium bromide (CTAB) and sodium metaborate (NaBO2). The study confirmed that C16mimBr and CTAB have similar aggregation behaviors and surface activities. The ETA–C16mimBr system proved to be compatible with brine containing an appreciable concentration of divalent cations. Studies on interfacial properties showed that the ETA–C16mimBr system exhibited an improved IFT reduction capability better than the NaBO2–CTAB system, attaining an ultra-low IFT of 7.6 × 10−3 mN/m. The IFT reduction performance of the ETA–C16mimBr system was improved in the presence of salt, attaining an ultra-low IFT of 2.3 × 10−3 mN/m. The system also maintained an ultra-low IFT even in high salinity conditions of 15 wt% NaCl concentration. Synergism was evident for the ETA–C16mimBr system also in altering the carbonate rock surface, while the wetting power of CTAB was not improved by the addition of NaBO2. Both the ETA–C16mimBr and NaBO2–CTAB systems proved to form stable emulsions even at elevated temperatures. This study, therefore, reveals that a combination of surface-active ionic liquid and organic alkali has excellent potential in enhancing the oil recovery in carbonate reservoirs at high salinity, high-temperature conditions in carbonate formations.  相似文献   

18.
Severe viscous fingering during water flooding of heavy oil leaves a large amount of oil untouched in the reservoir. Improving sweep efficiency is vital for increasing heavy oil recovery. Previous researches have proved that foam flooding can increase the sweep efficiency and oil recovery. The polymers could make the foam more stable and have better plugging capacity, but the interfacial tension (IFT) of oil and water increase which could decrease the displacement efficiency of the heavy oil. In view of the deficiency of conventional foam flooding, it is necessary to research the ultra-low interfacial tension foam which could improve macro-swept volume and micro-displacement efficiency in heavy oil reservoir. In this paper a novel foam agent is developed by the combination of surfactant and additives to lower the IFT of oil and water. The operating parameters including foam injections modes and gas liquid ratio were investigated by core flooding experiments. Field test performance shows that oil production per day increased from 85.6 to 125.7 t, water cut declined from 92.1 to 83.6% after 3 months injection. This study provides a novel method to improve heavy oil recovery with an ultra-low interfacial tension foam flooding system.  相似文献   

19.
An ultralow interfacial tension (IFT) oil displacement agent, which was a surfactant combinational system (HCS) with good salt and heat resistance, was synthesized using amphoteric betaine (AMS)/anionic sulfonate (AKS)/nonionic alkyl amide (NIS). The interface tensiometer was used to test the IFT. The results showed that the oil–water IFT could be as low as 10?4 mN/m when the salinity is 10,000~50,000?mg/L, the concentration is 1~5?g/L, and the temperature is 40~80°C. The surfactant system has good emulsification stability. The displacement simulation experiments demonstrated that the increment of the recovery ratio can be up to 14.1%. The surfactant system could meet the demands of site operation.  相似文献   

20.
采用动态激光光散射及环境扫描电镜研究了羧甲基纤维素系列高分子表面活性剂与大庆原油形成超低界面张力的机理.结果表明,CMC系列高分子表面活性剂具有与低分子量表面活性剂相比拟的表/界面活性,其水溶液的表面张力可达2835mN/m,界面张力达到10-110mN/m.碱的加入可显著降低高分子表面活性剂与原油的界面张力,在适当条件下界面张力达到超低值(10-3mN/m),可望作为三次采油的驱油剂.等效烷烃模型研究表明,用碱与原油酸性组分的作用来解释碱能使界面张力下降至超低值的传统观点是不完善的,加入碱能使高分子表面活性剂胶束解缔,胶束数量增多,胶束粒径减小,单分子自由链增加,有利于高分子表面活性剂向界面迁移和排布,这是高分子表面活性剂和碱复配体系与原油界面张力下降至超低值的主要原因.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号