OCS表面活性剂驱油体系与大庆原油间的动态界面张力研究

测定了OCS表面活性剂驱油体系与大庆原油间的动态界面张力.在大庆油田评价浓度范围内,考察了碱的类型与浓度、OCS浓度以及部分水解聚丙烯酰胺(HPAM)对动态界面张力的影响.结果表明,强碱(NaOH)体系比弱碱(Na2CO3)体系更容易形成超低界面张力(10-3mN/m),即体系达到超低界面张力的时问较短;高浓度碱体系比低浓度碱体系更容易形成超低界面张力;弱碱条件下,OCS表面活性剂浓度变化对动态界面张力有一定的影响;而强碱条件下则没有明显的影响;聚合物HPAM的引入使得不同体系达到超低界面张力的时间延长.     

石油羧酸盐及碱复合体系／大庆原油间的动态低界面张力研究

本探讨了石油羧酸盐及碱复合体系和大庆原油间的动态低界面张力形成的原因，并研究了盐含量、碱含量对其间动态低界面张力的影响。结果表明，低界面张力主要是石油羧酸盐活性剂的贡献，而动态低界面张力过程是由水相中碱与原油中的有机酸反应生成的界面活性物质引起的。在某一含量范围内，随ＮａＣｌ或ＮａＯＨ含量增加，动态低界面张力曲线移向低界面张力区。     

复合驱油体系与胜利原油间的动态界面张力特性

本文系统研究了不同离子强度和碱浓度条件下胜利原油－碱水体系的动态界面张力特性,考察了复合驱体系各组分对界面张力的影响,发现胜利原油与碱水间的界面张力在适宜的离子强度和碱浓度条件下达到最低,碱与表面活性剂之间的降低界面张力方面在明显的协同效应,而表面活性剂与聚合物之间不存在明显的协同效应。     

ASP体系与大庆原油的乳化作用及影响因素

ASP三元复合体系与原油之间的乳化作用与该体系提高采收率以及采出液分离的效果直接相关.通过建立的ASP三元复合体系与原油乳化能力的评价方法,给出了ASP三元组分对乳化作用的影响;并系统评价了作用力和作用方式、油水比、ASP三元组分的类型及质量分数等因素对乳状液的类型和稳定性的影响.碱在乳化过程中起到非常重要的作用,高质量分数的碱有利于乳化形成,碱的强度直接影响形成乳状液的类型和稳定性,而水溶性聚合物可通过提高水相粘度和油膜或水膜的强度而增强乳状液的稳定性.     

三元复合体系界面张力与驱油效率相关性研究

原有复合体系评价方法存在诸多问题,如评价方法未定量、不准确、不全面等问题。应系统地提出一套评价指标和评价标准,建立评价体系,有效地判别评价方法的可靠性,以便找出提高复合体系驱油效果的主要因素,进而提高石油采收率。针对大庆油田油层具体情况,研制出相同类型、相同用量、不同分子排布的表面活性剂,实现相同碱、聚合物、表面活性剂用量时,复合体系油水界面张力特征不同。通过岩心物理模拟实验,研究具有不同界面张力特征体系驱油效果,确定界面张力与驱油效率的关系。结合驱油实验结果,得出复合体系界面张力的评价标准,指导复合体系室内配方筛选及注入体系性能优化工作。     

原油性质对三元复合体系形成超低界面张力的影响

着重研究了在三元复合驱过程中 ,原油性质对于三元体系形成超低界面张力的影响 ,得到了一些有意义的认识 ,为今后研究三元复合驱油机理提供了新的思路。     

大庆原油馏分与复合体系界面活性及乳化性研究

为考察原油成分对复合体系界面活性的影响，将原油通过实沸点蒸馏法切割成不同的馏分，对各馏分与三元体系的动态界面张力进行了测定。还探讨了馏分油的乳化液稳定性及重组分对乳化液稳定性的影响。研究结果表明：与三元体系的界面张力，轻馏分最低，其次是重组分，再次是沸点依次升高的中间馏分；在轻馏分中加入重组分可以进一步降低界面张力；馏分油与二元（ Ａ／Ｓ） 体系形成的乳状液，其稳定性随馏分沸点升高而降低，加入重组分可提高乳状液的稳定性。     

强碱三元复合体系与大庆原油乳化作用

通过收集喇嘛甸、萨尔图和杏树岗等油田水驱目的层原油进行组分分析,开展了强碱三元复合体系与原油乳状液稳定性、药剂在油相中损耗量以及碱、表面活性剂和聚合物对乳状液稳定性影响研究。结果表明:喇嘛甸油田原油黏度、含蜡量和含胶量较高且酸性活性组分种类和数量较多,碱在油相中损耗量较多,乳状液稳定性较强;当原油中重质组分含量较高且碳链分布范围较广时,重烷基苯磺酸盐类表面活性剂在原油中损耗较大,乳状液稳定性较强;单一碱液与原油作用生成W/O型乳状液,"碱/表面活性剂"二元和"碱/表面活性剂/聚合物"三元复合体系与原油作用生成O/W型乳状液。     

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.     

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。     

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.     

Interfacial activity of alkyl hydroxyl sulfobetaine against crude oil

To study the interfacial activities of zwitterionic surfactant against crude oil, four alkyl hydroxyl sulfobetaines were synthesized. The effects of surfactant structure, concentration, salinity of formation water, and crude oil composition on interfacial activities were discussed. It shows that the octadecyl hydroxyl sulfobetaine can achieve ultralow interfacial tension at the concentrations no less than 0.001%, exhibiting a good interfacial activity and a very strong antidilution ability. The salinity of formation water has no obvious effect on lowering the interfacial tension and the polar component in crude oil is very crucial for the production of ultralow interfacial tension. This work is important for enhanced oil recovery.     

大庆原油含氮组分的界面扩张黏弹性质

 采用络合法和吸附色层法对大庆原油含氮组分进行了分离和富集,得到氮含量不同的2种含氮组分（以下简称 N1、N2）。采用悬挂滴方法,研究了 N1、N2在煤油-水界面上的扩张流变性质,考察了扩张频率和组分浓度对扩张模量和相角的影响。结果表明,N1、N2具有相近的相对分子质量,表现出大体类似的界面扩张变化规律;但由于氮含量不同,所以具有不同的界面扩张行为。组分浓度较低时,由于 N1的氮含量较高,其分子结构中含有更多的氮杂环,活性较强,体积较大,表现为油-水界面张力较低,扩张模量较大;组分浓度较高时,由于 N2分子体积较小,在油-水界面上排列更为紧密,易于在界面与体相间发生扩散交换,表现为油-水界面张力较低,扩张模量较小。2种含氮活性组分不同的界面扩张黏弹性质可从其不同特征的微观弛豫过程得到解释。     

Interfacial properties of Daqing crude oil-alkaline system

The oil/water interfacial properties of crude oil emulsions formed by alkaline/surfactant/ polymer（ASP） flooding in the Daqing Oilfield were investigated in this paper by the measurement of interfacial tension,interfacial shear viscosity and Zeta potential of the oil/water system.The result showed that both NaOH and Na₂CO₃ could react with acid substances in the crude oil to produce interfacially active components,which are adsorbed on the interfaces between the aqueous phase and oil phase, resulting in a decrease of the interfacial tension,negatively charging the surface of oil droplets,but making little change in the interfacial shear viscosity.For the same ionic strength of NaOH and Na₂CO₃, the interfacial tension of NaOH solution-crude oil system is lower,but the interfacial shear viscosity of NaOH solution-crude oil system is higher,than that of Na₂CO₃ solution-crude oil system.The negative value of the Zeta potential on the surface of the oil droplets is large.Accordingly,the O/W emulsion of NaOH solution-crude oil system is more stable than that of Na₂CO₃ solution-crude oil system.     

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.     

OCS表面活性剂中试产品应用于大庆原油的界面张力性能研究

研究了OCS表面活性剂中试产品在强碱NaOH条件下应用于大庆不同原油时的油-水界面张力特性。结果表明,对于大庆采油一厂至四厂的原油,OCS表面活性剂质量分数在0.1％～0.3％、NaOH质量分数在0.6％～1.2％的范围内,油-水界面张力可达到超低(约10~(-3)mN/m数量级),能够满足大庆油田复合驱用表面活性剂使油-水界面张力达到超低的要求。研究结果还表明,聚合物的加入有利于原油-表面活性剂体系间超低界面张力的形成。