电位滴定分析ASP驱采出液中表面活性剂浓度

以十二烷基磺酸钠为例,考察了利用电位滴定方法分析ASP三元复合驱采出液中表面活性剂浓度时,pH值、盐度、聚合物含量、石油酸皂浓度等因素对分析结果的影响,研究出因石油酸皂和聚合物的存在导致结果偏高的消除方法,并对方法的检出限进行研究。该方法为ASP三元驱中十二烷基磺酸钠类阴离子表面活性剂浓度的分析提供了参考。     

Stability of oil-in-water emulsions by SDS compound

Abstract

Surfactants are often required to reduce emulsion viscosity and heavy-oil flow resistance in pipelines, thereby forming a stable oil-in-water emulsion under shear stress. This study aimed to quantitatively discuss and analyze the stability of oil-in-water emulsions and characterize them through the initial viscosity change rate K. The value of K was obtained based on the oil-rich-phase viscosity curves of oil-in-water emulsions comprising sodium dodecyl sulfate (SDS), heavy oil, and water at different time points. Results showed that a smaller K corresponded to a more stable emulsion according to analysis of the effect of the compound system on emulsion stability and the synergistic mechanism. We then combined with 1-pentanol and octyldecyl glucoside (APG0810) with SDS. Results showed that the K values of the emulsions decreased from 19.457 to 6.284, and 19.457 to 5.834, respectively, after mixing 6% 1-pentanol and 0.4% APG, respectively, with 0.14% SDS. Then, 0.14% SDS was compared with 1.2% a mass fraction of each of the three additives to form a compound system, and the K values were found to follow the trend K_{1-pentanol/SDS} > K_APG/SDS. Thus, the stability of APG/SDS oil-in-water emulsion was better than that of 1-pentanol/SDS emulsion.     

Effects of Different Heavy Crude Oil Fractions on the Stability of Oil-in-Water Emulsion —Ⅲ. Effects of pH on the interfacial properties of heavy crude functional fractions and water system

In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric fraction and asphaltene is great. The interfacial pressure of fractions increases in strongly basic conditions. The ζ (-80mv) of acid fraction is the largest under basic conditions (pH=11-12), with the result to show that the interfacial activity of the acid fraction is superior to that of other fractions. The results of model emulsions show that strongly basic conolition (pH≥11) is beneficial to oil-in-water emulsion stability. The interfacial activity of acid fraction and asphaltene is superior to that of other crude fractions.     

Investigation of factors affecting on viscosity reduction of sludge from Iranian crude oil storage tanks

Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions (made of sludge, water and surfactant), such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants (like bitumen emulsifier), and solvents (such as mixed xylene, AW-400, and AW-402), injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island, Iran.     

Influence of surfactants used in surfactant-polymer flooding on the stability of Gudong crude oil emulsion

The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The influence of the surfactants on the stability of Gudong water-in-oil (W/O) and oil-in-water (O/W) emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.     

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     

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     

Prediction of the viscosity of water-in-oil emulsions

Water-in-oil (W/O) emulsions occur in different parts of petroleum recovery and since their properties are different from those of crude oil and water, it is essential to find information about their physical properties. The water causes some problems and heightens the cost of oil production. Separation of water from oil, water treatment, and disposal of water are the steps that make oil production costly. Among various physical properties of W/O emulsions, viscosity is the most important. Because of droplet crowding, emulsions indicate non-Newtonian behavior, which is why their viscosity is higher than the viscosity of oil and water. As a result, it is essential to have knowledge about the viscosity of W/O emulsions in order to extract and process petroleum properly. In this study, an intelligent model, namely a COA-LSSVM, is presented to accurately prognosticate the viscosity of W/O emulsions. The results indicated that the values estimated by the developed model is in great consistency with the laboratory data by R² of 0.9972 and MSE of 1.1762 * 10^?5. A comparison with another model, which was recently introduced, revealed that the developed model in this study is superior.     

RHEOLOGY, PARTICLE SIZE DISTRIBUTION, AND ASPHALTENE DEPOSITION OF VISCOUS ASPHALTIC CRUDE OIL-IN-WATER EMULSIONS FOR PIPELINE TRANSPORTATION

The rheology of an asphaltic heavy crude oil-in-water emulsions stabilized by an anionic (RN) and a nonionic (TEP) surfactants individually or in a mixture has been studied. The investigated crude oil has a non-Newtonian, time dependent, shear thickening, rheopectic behavior with a relatively high yield stress. The relatively high yield stress of this crude oil is attributed to the presence of a relatively high asphaltene and resins content. The viscosity ofhe crude oil decreases when it is emulsified with synthetic formation water in the form of an oil-in-water type of emulsion using a nonionic or an anionic surfactant. It has been found that, the maximum oil content required for forming an oil-in-water emulsion of acceptable viscosity is the 60% oil-containing emulsion. However, the 70% oil-containing emulsion is not an oil-in-water type of emulsion but it is rather a complicated mixture of oil-in-water-in-oil type of emulsion. The presence of the anionic and the nonionic surfactants together has a synergistic effect in decreasing the total surfactant concentration required to stabilize the emulsion and to form low viscosity emulsion. It has been emphasized that the nonionic surfactant has a positive contribution in forming emulsions with low viscosity. Meanwhile, the anionic surfactant contributes in stabilizing the emulsion at lower concentrations. Flocculation point measurements showed that the added surfactants caused no sign of asphaltene deposition. This implies that it is safe to use the investigated surfactants in forming oil-in-water emulsion for viscous asphaltic crude oils without any fear of asphaltene deposition.     

RHEOLOGY,PARTICLE SIZE DISTRIBUTION,AND ASPHALTENE DEPOSITION OF VISCOUS ASPHALTIC CRUDE OIL-IN-WATER EMULSIONS FOR PIPELINE TRANSPORTATION

The rheology of an asphaltic heavy crude oil-in-water emulsions stabilized by an anionic (RN) and a nonionic (TEP) surfactants individually or in a mixture has been studied. The investigated crude oil has a non-Newtonian, time dependent, shear thickening, rheopectic behavior with a relatively high yield stress. The relatively high yield stress of this crude oil is attributed to the presence of a relatively high asphaltene and resins content. The viscosity ofhe crude oil decreases when it is emulsified with synthetic formation water in the form of an oil-in-water type of emulsion using a nonionic or an anionic surfactant. It has been found that, the maximum oil content required for forming an oil-in-water emulsion of acceptable viscosity is the 60% oil-containing emulsion. However, the 70% oil-containing emulsion is not an oil-in-water type of emulsion but it is rather a complicated mixture of oil-in-water-in-oil type of emulsion. The presence of the anionic and the nonionic surfactants together has a synergistic effect in decreasing the total surfactant concentration required to stabilize the emulsion and to form low viscosity emulsion. It has been emphasized that the nonionic surfactant has a positive contribution in forming emulsions with low viscosity. Meanwhile, the anionic surfactant contributes in stabilizing the emulsion at lower concentrations. Flocculation point measurements showed that the added surfactants caused no sign of asphaltene deposition. This implies that it is safe to use the investigated surfactants in forming oil-in-water emulsion for viscous asphaltic crude oils without any fear of asphaltene deposition.     

耐盐耐高温超稠油降黏剂的研制与性能评价*

针对超稠油黏度高、流动性差和地层水矿化度高等现状,以表面活性剂、碱、有机磷酸为原料制得乳化降黏剂,对降黏剂配方进行了优选,研究了矿化度和温度对降黏剂降黏性能的影响,并分析了降黏机理。结果表明,超稠油乳化降黏剂最优配方为:质量比为1∶1的磺酸盐类阴离子表面活性剂YBH与醇醚羧酸盐类的阴、非离子表面活性剂YFBH复配的主剂、碱助剂、耐盐助剂NYZJ-1的质量比为1.1∶0.45∶1.15。在主剂、助剂总加剂量为0.81%(占原油乳状液的质量分数)、乳化温度80℃、油水质量比为7∶3、矿化度为95 g/L的条件下,可使超稠油黏度由316.5 Pa·s(50℃)降至其乳状液的0.0831 Pa·s,降黏率达99.97%,50℃下静置4 h的出水率为5.93%。温度对乳化降黏剂降黏性能的影响较小,经200℃处理2 h后超稠油乳状液的降黏率不变。复配乳化剂各组分间发挥了协同增效作用,增强了体系的降黏性能,提高了乳状液的稳定性。乳化降黏剂降黏效果良好,耐温抗盐,适用于高温高盐油藏。图10表3参15。     

Optimization of separation of oil from oil-in-water emulsion by demulsification using different demulsifiers

Separation of oil from oil-in-water emulsion is a major challenge in petroleum industries during the producing and refining process. The authors investigated characterization of oil-in-water emulsion and subsequently separation of oil from emulsion using different chemical dimulsifiers. The effect of settling time, pH, temperature, and demulsifier dosage on oil separation efficiency has been studied. It was observed that as time, temperature, and chemical dosage increased oil separation efficiency increased. Droplet size distribution of emulsions illustrated that the demulsifier could lead to the breakup of crude oil-in-water emulsions by flocculation and coalescence. More than 98% oil separations were observed with some demulsifiers under optimum operating conditions.     

Pickering乳状液稳定性的研究进展

从乳状液稳定机理、影响因素以及表面活性剂等活性物质对Pickering乳状液稳定性的影响进行了介绍,阐述了机械阻隔理论与三维黏弹粒子理论是主要稳定机理。评述了Pickering乳状液的应用前景,指出固体颗粒与聚合物的协同作用是否受其他因素影响值得研究,同时指出Pickering乳状液在石油行业的应用也值得探索,另外,研究响应环境刺激的固体颗粒乳化剂将拓宽Pickering乳状液的应用范围。     

Viscosity of Concentrated Emulsions: Relative Effect of Granulometry and Multiphase Morphology

Abstract

High viscosity and high density make heavy and extra heavy crude oils very difficult to produce. They cannot be pumped in their natural state and advanced technologies are required. Formation of oil-in-water emulsions is one of them. A typical emulsion contains 65% of dispersed phase and has a viscosity lower than 500 mPa.s. Current research is aimed at increasing the crude oil content at reduced costs with still good stability and low viscosity. Consequently, an experimental study was dedicated to the relationship between the structure and the rheological properties of heavy oil emulsions. Particular attention was paid to process parameters employed to prepare emulsions. Depending on the shear device, various emulsions have been obtained, either simple or multiple, monodisperse or bimodal. The resulting viscosity is discussed. It is particularly low when the emulsion is either coarse and unimodal or fine and simple. The highest viscosity is obtained when the emulsion is fine and multiple. The experimental results confirm that both composition variables and process parameters have to be taken into account to minimize viscosity of heavy oil emulsions.     

Modeling of flow of oil-in-water emulsions through porous media

Formation and flow of emulsions in porous media are common in all enhanced oil recovery techniques.In most cases,oil-in-water(O/W) emulsions are formed in porous media due to oil-water interaction.Even now,detailed flow mechanisms of emulsions through porous media are not well understood.In this study,variation of rate of flow of O/W emulsions with pressure drop was studied experimentally,and rheological parameters were calculated.The pressure drop increases with an increase in oil concentration in the O/W emulsion due to high viscosity.The effective viscosity of the emulsion was calculated from the derived model and expressed as a function of shear rate while flowing through porous media.Flow of O/W emulsions of different concentrations was evaluated in sand packs of different sand sizes.Emulsions were characterized by analyzing their stability,rheological properties,and temperature effects on rheological properties.     

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.     

甲醇柴油乳液的黏度特性

在恒定温度20℃、乳化时间2 min、搅拌速率5×2800 r/min的条件下,考察了复配乳化剂质量分数、种类和黏度及甲醇质量分数对甲醇柴油乳液黏度的影响。结果表明,在本实验条件下,甲醇柴油乳液近似为牛顿流体,乳化剂的种类、质量分数及乳液中甲醇的质量分数对乳液的黏度特性具有显著的影响。对于组分相同的甲醇柴油乳液,其黏度随着乳化剂质量分数及其黏度的增加而增大;当其他组分一定时,其黏度随着甲醇质量分数的增加而增大;所制备的甲醇柴油乳液的黏度在2.7~5.6 mPa·s之间,符合国家燃油黏度标准。     

表面活性剂增效碱驱中表面活性剂之间的协同效应

本文考虑了在碱（Ｎａ２ＣＯ３）性条件下表面活性剂之间在界面张力性质、耐盐性及驱油效率等方面的协同效应。实验结果表明，阴离子表面活性剂（石油磺酸盐）与非离子表面活性剂之间的复配，除在界面张力性质方面显现出比石油磺酸盐之间更好的协同效应外，石油磺酸盐在较高矿化度下的溶解性也获得根本改善，能够顺利通过孔隙介质并获得较高的驱油效率，长期放置亦无沉淀发生，为热力学稳定体系。     

Mechanism of the viscosity reduction with ternary compound in the sulfonate-straight chain alcohol-alkaline compound system

Research shows that the viscosity greatly reduction of viscous crude oil can improve the exploitation and promote the fluidity. We studied the effects and the mechanism of viscosity reduction of viscous crude oil emulsion after introducing the ternary compound of sulfonate-straight chain alcohol-alkaline as the viscosity reducer. Results showed that the best emulsifying performance can be achieved using 5% 1-pentanol. 0.2% of Na₂CO₃ and DEA shows the strongest emulsification ability of the O/W emulsion. The use of AOS, straight chain alcohol and petroleum carboxylate resolves diffusion on the oil-water interface, which can form a dense surfactant of single molecular layer to reduce the interfacial tension and prevent the phase change of the emulsification. When the mass fraction of AOS, Na₂CO₃, DEA and 1-pentanol were 0.2%, 0.25%, 0.2% and 5% respectively, the viscous crude oil would achieve the best effect of viscosity reduction.     

油水乳化转相黏度预测实验研究

应用高温、高压流体黏度测量装置，模拟地层条件，测试新疆塔河油田油水乳化液的黏度，测试结果表明其转相点在含水率为50%～60%.绘制相应的测试曲线，分析含水率与油水乳化液黏度的关系，井用高斯函数和劳伦兹函数拟合测试曲线。拟合结果表明，在地层条件下，乳化液黏度的变化规律符合高斯函数和劳伦兹函数，与常温、常压下不含气的油水乳化液黏度的变化规律相类似。据此建立了黏度预测数学模型，预测结果表明，在含水率高于50%时，用高斯、劳伦兹函数预测的油水乳化液黏度误差较小，为原油在地层，井筒及箱油管道中的流动计算提供了科学依据。图4表7参10