界面特性表征驱油剂对采出液稳定性的影响

针对三元复合驱不同驱油剂对采出液稳定性的影响问题,通过室内破乳脱水实验及油水界面张力、zeta电位、黏度等参数,研究了不同驱油剂对三元复合驱采出乳状液稳定性的影响。结果表明:单一的碱和表面活性剂能够降低油水界面张力、增加zeta电位,从而减少脱水率、增强稳定性;聚合物则主要是增加zeta电位和体系黏度从而脱水率减少,稳定性增强;当多种驱油剂共同存在时乳状液成分复杂,乳化严重,乳状液更加稳定。因此可通过界面特性参数找出三元复合驱驱油剂对采出液稳定性的影响变化规律,为油田现场提供合理的驱油药剂。     

模拟二元复合驱采出液稳定性影响因素研究

二元复合驱是中高渗透油藏提高采收率的主要技术之一。为了研究聚表二元驱对乳状液稳定性的影响,选取含聚表水与模拟油组成油水界面体系,测试了油水界面张力、界面剪切黏度等参数,并结合乳状液静置脱水效果,分析聚表二元驱对油水采出液稳定性的作用机理。采用含聚合物和表面活性剂的水相与模拟油配制成模拟油采出液,用于测试不同聚合物及表面活性剂浓度对界面张力的影响。界面张力结果表明:聚表二元驱成分能够显著增大油水乳状液的稳定性,但聚合物与表面活性剂在界面活性上存在明显差异;界面剪切黏度的影响因素主要为聚合物;静置脱水实验表明,影响油水乳状液稳定性的主要因素为表面活性剂。这与过去的观点存在矛盾,即认为界面剪切黏度是影响乳状液稳定性的关键。因此本研究认为存在其他因素影响乳状液稳定性。     

驱油剂对弱碱三元采出液油水界面张力的影响

研究了碱、表面活性剂和聚合物对石油磺酸盐表面活性剂弱碱体系三元复合驱采出液油水界面张力的影响。实验结果表明,油水动态界面张力随表面活性剂和碱含量增大而降低;在表面活性剂和碱共同作用下,模拟三元复合驱采出液油水动态界面张力下降显著;加入聚合物会使油水动态界面张力升高,但与碱和表活剂相比,聚合物对油水动态界面张力的影响不大。     

胜利油田二元驱采出液中乳状液的稳定性研究

针对胜利油田二元驱采出液处理难度大的问题,以二元驱采出液中乳状液为研究对象,对其开展了界面性能、界面黏弹性、界面膜微观结构以及Zeta电位的室内分析研究。结果表明,二元驱采出液中的乳状液稳定性主要由界面膜强度决定,体系的双电层结构对乳状液的稳定性有一定的促进作用。     

驱油剂对三元复合驱采出液破乳脱水的影响

研究了驱油剂对三元复合驱模拟采出液破乳脱水效果的影响规律,单一的碱、表面活性剂和聚合物对脱水率和水色有较大的影响;3种驱油剂之间存在明显的协同作用,对脱水率和脱出水色的影响很大.显微照片验证了含驱油剂的乳液存在多重乳状液.根据破乳机理和三元复合驱采出液的特点,提出了合成新型破乳剂的研究思路.     

二元驱采出污水组分对水性质的影响

针对二元驱中采出液成分复杂、稳定性高、油水分离难度等问题,对二元驱采出污水组分对水性质的影响进行了研究。结果显示:表面活性剂的加入增加了含油污水油水分离的难度,且浓度越高,沉降分离的效果越差;同时表面活性剂能够使油水界面的界面张力降低,使油滴表面Zeta电位绝对值增加,但对油水界面剪切粘度几乎无影响;聚合物/表面活性剂二元复合体系中,聚合物、表面活性剂及水中悬浮物形成了具有类似"晶体"结构的热力学不稳定体系。     

二元复合驱采出液的油水界面性质和破乳条件的关系

用界面张力仪和表面粘弹性仪研究了部分水解聚丙烯酰胺(HPAM)和表面活性剂(石油磺酸盐和非离子型表面活性剂)形成的二元复合体系对模拟油与模拟水(简称油水)界面特性、乳状液稳定性和采出液处理效果的影响。实验结果表明,含固体悬浮物的采出液过滤后与模拟油间的界面张力和界面剪切黏度降低;随表面活性剂浓度的增加,油水间的界面张力和界面剪切黏度降低,而随HPAM浓度的增加,油水间的界面张力和界面剪切黏度增加;原油与二元复合体系所形成的W/O和O/W型乳状液稳定性随HPAM和表面活性剂浓度的增加而提高;采出液中HPAM和表面活性剂的浓度增加,处理采出液的效果变差。     

表征化学驱采出液稳定性不同指标的关联性

研究了聚合物、石油磺酸盐及二元复合驱作为驱油剂对孤岛油田采出的原油乳状液稳定性的影响,考察用不同指标表征乳状液稳定性的关联性。结果表明,在60℃、破乳剂TA1031质量浓度为100mg/L时,随各种驱油剂质量浓度的增大,原油乳状液破乳脱水率降低,120min时脱水率由高到低的原油乳状液体系的顺序为石油磺酸盐体系、聚合物体系、二元复合驱体系,对应的稳定性评分SV值逐渐增大,体系的静态稳定性逐渐增强;对应的破乳后水相Zeta电位绝对值、电导率由大到小的顺序为二元复合驱体系、聚合物体系、石油磺酸盐体系;水相中的油滴中值粒径由大到小的顺序为石油磺酸盐体系、聚合物体系、二元复合驱体系。水相的Zeta电位值越负、电导率越高、水中油滴中值粒径越小,原油乳状液的稳定性越强,脱水率也越低,表明表征化学驱采出液稳定性的各指标具有很好的关联性。     

两亲聚合物驱油剂对渤海油田采出液处理的影响

针对两亲聚合物驱油剂,研究了两亲聚合物对渤海油田原油乳状液和生产污水稳定性影响的规律性,探讨了两亲聚合物的结构和界面性能对采出液处理效果的影响。实验结果表明：①两亲聚合物对原油乳状液和污水体系的稳定性有明显影响;②随着聚合物浓度的升高,原油乳状液中的分散相水珠的直径明显变小,破乳难度增大,污水体系中的分散相油珠聚并的难度明显增加,且易形成水包油型乳状液;③两亲聚合物具有一定的界面活性,对采出液具有一定的乳化作用。     

碱对三元复合驱采出液油：水乳状液稳定性的影响

在三元复合驱中,加入的碱与原油中的组分发生反应,使油水形成稳定的乳状液,所以油水分离变得比较困难.通过研究碱溶液与模型油形成的油水乳状液的稳定性表明,用碳酸钠作为碱,和原油中的胶质及沥青质反应,生成了界面活性泡沫.用氢氧化钠作为碱,在油藏滞留的时间里形成了羧酸钠盐.     

管输压力下实时记录式天然气发热量测定设备的开发

通过破乳脱水实验及界面性质研究了HPAM、吡咯林及其二元驱体系对原油乳状液稳定性的影响。实验结果表明:加入浓度为100mg/L不同驱油剂后均使破乳剂BSE-238对原油乳状液的脱水率降低15%以上,SV值均增大,不同驱油剂均增强了原油乳状液的稳定性。含驱油剂的乳状液体系破乳后水相电导率增大、Zeta电位负值增大,破乳脱出水中含油量增大、油滴粒径减小。不同驱油剂影响乳状液稳定性的机理不同:HPAM对体系界面张力无明显影响,是通过增大体系黏度增强其稳定性;吡咯林对乳状液体系黏度无影响,大大降低油水界面张力而增强乳状液稳定性;两种驱油剂协同作用,使二元驱采出液更加稳定。     

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.     

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.     

碱对部分水解聚丙烯酰胺溶液与煤油界面性质的影响

应用乌式粘度计和电导率仪,采用动态光散射法,测定了加碱前后聚合物溶液的部分水解聚丙烯酰胺分子线团粒径分布、体相粘度和电导率,考察了NaOH对部分水解聚丙烯酰胺的分子链、水解和溶液离子强度的影响.用界面剪切粘度仪、zeta电位仪和界面张力仪研究了NaOH的加入对部分水解聚丙烯酰胺与煤油之间界面性质的影响.结果表明:随着放置时问的延长,聚合物溶液自身会发生降解;碱使溶液中的离子强度增加,聚合物溶液在碱性环境下水解.碱导致聚合物溶液电导率增加,体相粘度下降,但对聚合物分子链没有明显影响.在界面性质方面,加碱后,聚合物溶液界面张力有所下降,油水界面剪切粘度大幅下降,离子强度和碱性水解的双方面原因导致了Zeta电位负值先增加,再逐渐减小.     

Influence of polymers on the stability of Gudao crude oil emulsions

The influence of different types and concentrations of polymers on the stability of Gudao crude oil emulsion was investigated by measuring the volume of water separated from the emulsions and the interfacial shear viscosity of the oil/water interfacial film. Experimental results indicate that the simulated water-in-oil emulsion with 40 mg/L of partially hydrolyzed polyacrylamide （HPAM） 3530S could be easily broken by adding demulsifier C and was readily separated into two layers. However, HPAM AX-74H and hydrophobically associating water-soluble polymer （HAP） could stabilize the crude oil emulsion. With increasing concentration of AX-74H and HAP, crude oil emulsions became more stable. Water droplets were loosely packed in the water-in model oil emulsion containing HPAM 3530S, but water droplets were smaller and more closely packed in the emulsion containing AX-74H or HAP. The polymers could be adsorbed on the oil/water interface, thereby increasing the strength of the interracial film and enhancing the emulsion stability.     

Effect of active species in crude oil on the interfacial tension behavior of alkali/synthetic surfactants/crude oil systems

The effect of active species present in crude oil on the interfacial tension （IFT） behavior of alkali/synthetic surfactants/crude oil systems was studied. The system consisted of heavy alkyl benzene sulfonate, sodium chloride, sodium hydrate and Daqing crude oil. Experimental results indicated that active species would diffuse from oil/aqueous interface to aqueous phase and finally an equilibrium could be reached in the system with increasing contact time. Moreover, the minimum IFT and equilibrium IFT values increased with increasing contact time and a linear relationship existed between dynamic IFT and f^-1/2 when IFT value approaching the minimum and after the minimum IFT was reached. This indicated that the dynamic IFT-time behavior was diffusion controlled. The oil and aqueous phases were analyzed by infrared （IR） spectroscopy. IR spectra of oil and aqueous phases illustrated that the content of active species in the oil phase decreased, but the content of active species in the aqueous phase increased after alkali reacted with crude oil. This indicated that the active species present in oil played an important role in reducing IFT.     

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。     

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.     

络合剂改善无碱一元和二元复合驱油体系的增粘能力和油水界面性能

通过研究络合剂对部分水解聚丙烯酰胺(HPAM)和直链烷基甜菜碱(BH)粘度和油水界面张力的影响,探讨了在高矿化度条件下,利用络合剂作为助剂改善无碱一元和二元复合驱油体系增粘能力和油水界面性能的方法。结果表明,在NaCl,CaCl2和MgCl2的质量浓度分别为6 500,890和520 mg/L的矿化水中,质量浓度为50 mg/L的络合剂就可以使质量浓度为1 800 mg/L的HPAM的粘度增加80%以上,可以使质量浓度为800~3 000 mg/L的直链烷基甜菜碱BH与原油的最低界面张力由10-2mN/m数量级降低到超低水平,而且这种络合剂也可以使1 800 mg/L HPAM—800 mg/L BH二元复合体系老化30 d的粘度增加40%以上,并使油水界面张力最低值由1.52×10-2mN/m降低到6.06×10-3mN/m。通过考察粘度和油水动态界面张力随不同老化时间的变化规律,分析了络合剂的作用机制。