低浓度表面活性剂-聚合物二元复合驱油体系的分子模拟与配方设计

 采用耗散颗粒动力学（DPD）方法在介观层次上模拟了表面活性剂烷基苯磺酸盐在油-水界面的排布行为,考察了分子结构、油相等因素对界面密度和界面效率的影响,探讨了利用表面活性剂复配协同效应提高界面活性的机理。实验研究了表面活性剂类型、油相、表面活性剂复配等对油-水界面张力的影响。结果表明,“阴-非”表面活性剂复配可使油-水界面张力降低1个数量级。根据分子模拟和实验研究结果,结合孤东七区试验区原油特点,提出了“0.3%”石油磺酸盐 + 0.1%表面活性剂1^#+0.15%聚合物"的二元复合驱配方,可使油-水界面张力降低至2.95×10^-3 mN/m,物理模拟实验提高采收率高达18.1%。     

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。     

原油复配破乳剂的配方设计

研究了水相pH值、非离子破乳剂和助剂对沙轻原油、阿曼原油、杰诺原油、胜利原油乳液稳定性的影响 ,考察了破乳剂与助剂的协同效应。结果表明 :沙轻原油在水相 pH =6～ 7时乳液的稳定性最差 ;破乳剂通过降低界面张力和使沥青质胶团向油相解缔而破坏乳液的稳定性 ;有机小分子助剂改变界面极性环境或增加芳香度使沥青质增溶而破坏乳液的稳定性 ,它们与破乳剂有很好的协同效应     

三种水处理剂对活性剂污水溶液和孤东原油间界面张力的影响

针对孤东原油与现场采出污水配制的表面活性剂溶液间界面张力不能达到超低界面张力的问题,研究了Na5P3O10、HEDP·Na4和ATMP·Na5三种水处理剂对表面活性剂污水溶液与孤东原油之间界面张力的影响规律,确定了三种水处理剂的最佳使用浓度范围。结果表明：当表面活性剂浓度为0．3％时,加入水处理剂后油水界面张力值显著降低,加Na5P3O10的油水界面张力先出现最低值后又逐渐升到平衡值,而加HEDP·Na4。和ATMP·Na5时都能使胜利原油与污水间界面张力最低值达到超低范围,HEDP·Na4的浓度范围最宽,为2000mg／L～4500mg／L。     

原油乳状液稳定性研究 Ⅱ.原油成分对原油乳状液稳定性的影响

原血成分的表面活性物质及其细微固体颗粒,在油水界面上相互作用是原油乳状液其有稳定性的主要原因。本文采用简单的方法将原油中众多的物质分成两大类,并根椐它们单独时或混合后对癸烷/水乳状液稳定性作用的特征,将其分别称为原油乳化剂和原油破乳剂。试验表明,原油乳状液稳定性的高低主要取决于所含的这两大类物质的多少和相对比例,其相对重要性可由界面张力定性地反映出来;并且由原油/水界面张力的大小可以定性地评估原油乳状液的稳定性。     

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。     

胜利油区二元复合驱油先导试验驱油体系及方案优化研究

首先根据胜利油区的油藏特点和复合驱的特点,在孤东油田七区西南Ng54-61层优选出了具有广泛代表性的试验区。然后根据试验区具体的油藏情况,室内筛选出了适合该油藏类型的以石油磺酸盐为主剂的二元复合驱油体系,研究表明,该体系可与模拟油达到超低界面张力状态,其吸附量较小、乳化性能和热稳定性好,驱油效果好。结合室内研究的结果,在建立基于模糊综合评判模型的二元复合驱注采参数优化设计方法的基础上,对化学剂组合方式、配方浓度、段塞尺寸、注入方式、注采速度等参数进行了优化。综合研究认为,该二元复合驱油体系驱油效率高、油藏适应性强,可较大幅度提高采收率。     

复合驱油体系与大庆原油间界面张力的研究

本文讨论了石油磺酸盐Ｂ—１００体系和Ｎａ２ＣＯ３体系与大庆原油间的界面张力等值图；讨论了Ｂ－１００－Ｎａ２ＣＯ３体系、Ｂ－１００—Ｎａ２ＣＯ３—３３３０Ｓ体系与大庆原油间的界面张力等值图。研究了表面活性剂的类型和浓度、碱的类型和浓度及地层水矿化度等对复合体系界面张力的影响。通过以上这些研究，探讨了碱——表面活性剂二元复合体系及碱—表面活性剂——聚合物三元复合体系与大庆原油间形成超低界面张力的机理。研究结果在理论上为大庆油田开展三元复合驱提供了充实的实验依据。     

STABILITY AND RHEOLOGY OF HEAVY CRUDE OIL-IN-WATER EMULSION STABILIZED BY AN ANIONIC- NONIONIC SURFACTANT MIXTURE

The stability and rheology of an Egyptian Heavy crude oil-in-water emulsions stabilized by an anionic (TDS) and a nonionic (NPE) surfactants individually or in a mixture have been studied. The study reveals that, the viscosity of the crude oil decreases when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration and speed of mixing of the emulsion increases. Fresh water and synthetic formation water have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in synthetic formation water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing fresh water is always less than that containing formation water, these findings have been correlated with the crude oil/water interracial tension (IFT) measurements The decreased IFT value results in a decrease in the average particle size of the dispersed crude oil leading     

STABILITY AND RHEOLOGY OF HEAVY CRUDE OIL-IN-WATER EMULSION STABILIZED BY AN ANIONIC- NONIONIC SURFACTANT MIXTURE

ABSTRACT

The stability and rheology of an Egyptian Heavy crude oil-in-water emulsions stabilized by an anionic (TDS) and a nonionic (NPE) surfactants individually or in a mixture have been studied. The study reveals that, the viscosity of the crude oil decreases when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration and speed of mixing of the emulsion increases. Fresh water and synthetic formation water have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in synthetic formation water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing fresh water is always less than that containing formation water, these findings have been correlated with the crude oil/water interracial tension (IFT) measurements The decreased IFT value results in a decrease in the average particle size of the dispersed crude oil leading     

Emulsification of Indian heavy crude oil using a novel surfactant for pipeline transportation

The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower(Helianthus annuus)oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension(IFT)between the crude oil(diluted)and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.     

驱油用耐温抗盐表面活性剂的研究进展

综述了国内外表面活性剂复配体系、阴离子-非离子两性表面活性剂和双子型(Gemini)表面活性剂3类驱油用耐温抗盐表面活性剂的研究进展情况,指出阴离子-非离子两性表面活性剂和新型Gemini表面活性剂是具有良好应有前景的高温、高盐油藏用表面活性剂,而且通过与石油磺酸盐和羧酸盐等廉价的表面活性剂进行复配使用,可以降低驱油成本。     

用动界面张力方法研究原油/盐水界面的性质Ⅰ.原油天然表面活性剂和破乳剂的竞争吸附现象

测定了原油 /盐水的动界面张力 ,比较了在无破乳剂存在时几种体系的动界面张力曲线。证明了原油天然表面活性剂分子渐渐扩散吸附到原油 /盐水界面上 ,当体系中有破乳剂存在时 ,破乳剂分子以竞争的方式扩散吸附到原油 /盐水界面上。用动界面张力方法研究原油天然表面活性剂和破乳剂在原油 /盐水界面的吸附速率对研究原油乳状液的破乳机理和优化破乳条件十分重要。     

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。     

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.     

SODIUM LIGNIN SULFONATE TO STABILIZE HEAVY CRUDE OIL-IN-WATER EMULSIONS FOR PIPELINE TRANSPORTATION

ABSTRACT

The efficiency of sodium lignin sulfonate (SLS) as an anionic surfactant derived from waste wood pulping industry in stabilizing an Egyptian heavy crude oil (Geisum)-in-water emulsions for pipeline transportation has been investigated. The stability and rheology of the emulsions stabilized by SLS or with a nonionic surfactant nonyl phenol diethylenetriamine formaldehyde ethoxylate (NDFE) individually or in a mixture have been studied. It has been found that the dynamic shear viscosity of the crude oil decreases substantially when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration increases. Potable water and saline water containing different molar concentrations of NaCI have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in saline water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing potable water is always less than that containing saline water and the viscosity increases as the salt content increased.     

SODIUM LIGNIN SULFONATE TO STABILIZE HEAVY CRUDE OIL-IN-WATER EMULSIONS FOR PIPELINE TRANSPORTATION

The efficiency of sodium lignin sulfonate (SLS) as an anionic surfactant derived from waste wood pulping industry in stabilizing an Egyptian heavy crude oil (Geisum)-in-water emulsions for pipeline transportation has been investigated. The stability and rheology of the emulsions stabilized by SLS or with a nonionic surfactant nonyl phenol diethylenetriamine formaldehyde ethoxylate (NDFE) individually or in a mixture have been studied. It has been found that the dynamic shear viscosity of the crude oil decreases substantially when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration increases. Potable water and saline water containing different molar concentrations of NaCI have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in saline water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing potable water is always less than that containing saline water and the viscosity increases as the salt content increased.     

EFFECT OF ASPHALTENE AND RESINS ON THE STABILITY OF WATER-IN-WAXY OIL EMULSIONS

Asphaltene, resins and paraffin waxes, their mutual interactions and their influence on the stability of water-in-oil emulsions have been studied. 20 wt % paraffin wax dissolved in decalin was used to model the waxy crude oil. Asphaltene and resins separated from a crude oil were used to stabilize the water-in-oil emulsions. Synthetic formation water was utilized as the aqueous phase of the emulsion. The emulsion stability increased with increasing the concentration of asphaltene with a subsequent decrease in the average particle size distribution of the emulsion. Resins alone are not capable of stabilizing the emulsion, however, in the presence of asphaltene they form very stable emulsions. Dynamic viscosity and pour point measurements provided evidence for resins-paraffin waxes interactions. Asphaltene in the form of solid aggregates form suitable nuclei for the wax crystallites to build over with a mechanism similar to that of paraffin wax crystal-modifiers. As asphaltene are polar in nature they are derived at the oil/water interface which was proved by the ability of asphaltene to reduce oil/water interfacial tension. Consequently, nucleation of the wax crystallites by asphaltene and resins at the interface will add to the thickness of the oil-water interfacial film and hence increase the stability of the emulsion.     

原油中天然表面活性剂的分离和性质研究

用乳化法分离出Ｐｒｅａｌｐｉｎｅ地区油中的天然表面活性剂,将它分散到液体石蜡中,测定了该分散液的表面张力,界面张力。考察了盐度水相ＰＨ值对界面张力的影响。另外,还以此分散液制备了一些太液,比较了它们的稳定性,了盐度和水相ＰＨ值对状液稳定性的影响。     

生物基两性离子型表面活性剂在不同驱油体系中的乳化稳定动力学

为探索生物基两性离子型表面活性剂（CNBS）在矿化度高于5 g/L体系中的驱油性能,研究该表面活性剂在不同驱油体系中的界面活性和乳化稳定动力学。结果表明,当该表面活性剂质量浓度为1.29 g/L、矿化度为32 g/L、NaOH质量分数为2.5%时,形成稳定W/O型乳状液,油/水界面张力降低至9.60×10^-4mN/m。当体系中总含水体积分数在40%～80%范围时,表面活性剂的加入有利于形成W/O型乳状液,且表面活性剂浓度是影响模拟乳状液稳定动力学的关键因素;随其浓度增大,模拟乳状液的破裂速率常数降低、半衰期和油相含水率增大,模拟乳状液的稳定性增强;当表面活性剂质量浓度为1.50 g/L,模拟乳状液稳定性最好。该表面活性剂与NaOH和黏均相对分子质量为2.5×10⁷的部分水解聚丙烯酰胺（HPAM）具有良好的协同效应,当表面活性剂浓度较低时,三元体系形成稳定W/O型乳状液。分子动力学模拟结果表明,油/水中加入该表面活性剂可使油/水界面膜厚度增大、界面能降低,形成稳定的乳状液;体系中加入NaCl和NaOH,油/水界面膜厚度和界面能均降低,乳状液的稳定性增强。