ISOLATION AND CHARACTERIZATION OF NATURAL SURFACTANTS FROM CHINESE OIL SAND BITUMENS

Abstract

Natural surfactants(NS) have been isolated from four Chinese oil sand bitumens (NNY,NSY,SNE,SUG) using the method of solvent extraction. These compounds were analyzed by IR and their interfacial tension (γ) against pH were measured. The results were compared with these obtained for fractions separated from the bitumen by conventional methods. The factors of NS to the extraction of bitumen from oil sand by hot water were investigated.     

ISOLATION AND CHARACTERIZATION OF NATURAL SURFACTANTS FROM CHINESE OIL SAND BITUMENS

Natural surfactants(NS) have been isolated from four Chinese oil sand bitumens (NNY,NSY,SNE,SUG) using the method of solvent extraction. These compounds were analyzed by IR and their interfacial tension (γ) against pH were measured. The results were compared with these obtained for fractions separated from the bitumen by conventional methods. The factors of NS to the extraction of bitumen from oil sand by hot water were investigated.     

MINERAL MATTER AND CLAY-ORGANIC COMPLEXES IN OIL SANDS EXTRACTION PROCESSES

ABSTRACT

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the bitumen product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed.

The samples were obtained from Suncor's oil sands extraction plant located in Fort McMurray, Alberta. Samples were obtained from throughout the extraction process from the primary froth through to the final diluted bitumen product. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as well as with other techniques such as interfacial tension measurements. The data indicates that high water content products originate, to a great extent, from the presence of a very hydrophilic organic matrix attached to the surface of the clay and heavy metal minerals.     

Dynamic Interfacial Tension Between Gudao Heavy Oil and Petroleum Sulfonate/HPAM Complex Systems

Abstract

The dynamic interfacial tension between Gudao heavy oil and petroleum sulfonate/hydrolyzed polyacrylamide complex system was studied. It is shown that with the addition of hydrolyzed polyacrylamide into the solution of petroleum sulfonate, not only is the viscosity of the complex system increased, but also the dynamic interfacial tension is further lowered. Thus a complex system with high viscosity and low interfacial tension can be constituted by 0.3 wt% petroleum sulfonate and 0.18 wt% hydrolyzed polyacrylamide with a viscosity-averaged molecular weight of 1 × 10⁷. In addition, the dynamic interfacial tension between complex system and crude oil can also be lowered by increasing the salt content in solution.     

原油乳状液油-水界面上活性物的结构和活性

通过综合的方法分离出大庆原油和胜利原油乳状液油-水界面上的活性物，用元素分析、红外、核磁、色质联用等方法分析其化学结构，并在油饿水模型体系中测定了它们的动态界面张力，考察其化学结构与界面活性之间的关系。结果表明，水相的pH值影响原油中的含氧化合物在油．水界面膜上的吸附；沥青、胶质和蜡是界面活性物的主要成分，对油-水界面膜的形成和稳定起着重要的作用；原油的酸性组分对油-水界面膜的动态界面张力有着决定性的影响。     

A New Type of Surfactant for Enhanced Oil Recovery

abstract

Most naturally fractured reservoir rocks are mixed to oil wet and do not imbibe the injected water, which translates into low-efficiency waterflood recovery. To enhance the spontaneous imbibition process, a low concentration of surfactants is dissolved into the injected water to induce wettability alteration of the reservoir rock by changing the wettability of the rock toward a more water-wet state. Zizyphus spina-christi leaves, which are grown in the Middle East, produce a special surfactant called saponin. This surfactant can be used for chemical flooding in Iranian oil fields due to its low cost and availability. Saponin was extracted from leaves using a spray-drying method and the interfacial tension (IFT) between saponin–water–oil was determined. For interfacial tension measurements the pendant drop method was used. A typical pendant drop apparatus is presented in this article. The algorithms used to infer interfacial tension from the geometrical profile of the pendant drop are described in detail; in particular, a new method for evaluation of the value of the radius at the apex of the drop, necessary for calculation of interfacial tension, is presented. Saponin caused a reduction in interfacial tension from 48 to 9 dyn/cm, which can be decreased to ultralow IFT by the addition of salt and alcohol. According to the results, saponin can be used as a surface-active agent for enhanced oil recovery.     

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。     

CHARACTERIZATION OF OIL SANDS MINERAL COMPONENTS AND CLAY-ORGANIC COMPLEXES

ABSTRACT

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as veil as with other techniques such as interfacial tension measurements.     

DESTABILIZATION OF WATER IN BITUMEN EMULSION BY WASHING WITH WATER

ABSTRACT

In order to get more information about the mechanism of stabilization of water-in-diluted-bitumen emulsion, bitumen diluted with toluene (10%, 25%, and 50% in volume) was “washed” using different amounts of water (0.20% in volume). The washing water was emulsified and then separated by high-speed ultra-centrifugation. The supernatant was then used to create a second w/o emulsion with the addition of new water. Stability of the new emulsion was measured in terms of the water separation rate under a low centrifugal force

It has been found that a very stable w/o emulsion was obtained in original diluted bitumen. However, after the diluted bitumen was pre-washed with a few per cent of water, the second emulsion became unstable. This indicates a significant effect of pre-washing with water on emulsion stability, possibly through the removal of emulsion stabilizing agents. Based on analytical results such as surface tension, and FTIR spectra, it appears that a small fraction of bitumen, mostly polar compounds such as carbonic acids and other oxygen-containing compounds, are responsible for the emulsion stabilization. Emulsion stability decreases with increasing volume of washing water but increases with the bitumen concentration.     

Dynamic Interfacial Tension Between Crude Oil and Novel Surfactant Flooding Systems Without Alkali

Abstract

The surface tensions of tetradecylmethylnaphthalene sulfonate (TMNS) surfactant aqueous solution and the dynamic interfacial tension (DIT) between crude oil, from Shandong Shengli oil field of China, and the surfactant solution without alkaline, was measured. Results indicate that the TMNS surfactant had great capability and efficiency of lowering the solution surface tension. The critical micelle concentration (cmc) is 0.001 mass% and the surface tension at this concentration is 28.19 mN.m^?1. It was also found that the TMNS surfactant is greatly effective in reducing the interfacial tensions and can lower the tension of crude oil-water interface to ultra-low at very low concentration, 0.002 mass%, without alkali and other additives. Both chromatogram separation of flooding and breakage of stratum are avoided effectively. The lower salinity is favorable for the flooding systems, lowering the DIT. The synthesized TMNS surfactant flooding systems without alkali and sodium chloride, decreasing the cost of oil recovery and avoiding the stratum being destroyed, would have a great prospect for enhanced oil recovery (EOR).     

大庆油田三元复合驱驱油效果影响因素实验研究

通过岩心物理模拟实验及微观驱油实验,分析了界面张力、三元体系粘度、乳化油滴产生及岩石润湿性对三元复合驱驱油效果的影响规律和影响机理。研究结果表明,油水间平衡、动态界面张力大幅度降低可有效提高三元复合驱驱油效率,进行三元复合驱时,油水界面张力须降到10^-3mN/m数量级;增加体系粘度能够扩大三元复合驱的波及体积,水油粘度比大于2是三元复合驱提高采收率幅度达到20%的必要条件;乳化的油滴产生是三元复合驱提高驱油效率的主要形式,油水界面张力越低、驱替体系粘度越大,乳化油滴的产生能力越强,驱油效果越好;三元复合驱能够驱替亲油岩石表面的油膜,促进岩心润湿性由亲油向亲水转化。     

双子表面活性剂与原油间动态界面张力研究

通过进行油水动态界面张力测试,系统地研究表面活性剂种类、表面活性剂浓度、水介质矿化度、聚合物及非离子表面活性剂对动态界面张力的影响。结果表明,与传统表面活性剂比12-4-12有较强界面活性,在低浓度下,能将界面张力降低到5×10-3 mN/m。提高表面活性剂浓度,可以缩短达到平衡的时间,但当浓度超过一定值时,继续增加12-4-12浓度,会降低其界面活性。12-4-12最佳浓度为500 mg/L。12-4-12在不同矿化度都表现出良好界面活性,尤其在高矿化度下(25×104 mg/L)最佳。在高矿化度水介质中与常规非离子表面活性剂ANT复配,界面张力可降低到4×10-3 mN/m并稳定在10-3数量级,而与HPAM的复配性能较差,这可能与水介质矿化度过高有关。     

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.     

Petroleum Sulfonates as Oil Displacement Agents and Application to Gudao Oil Field

Abstract

In terms of the condition of injection of water after polymer flooding of the Gudao oil field (Shengli, China), the following water quickly broke though the bank to the production wells, while most of residual oil remained in the formation. To solve the problem, two types of petroleum sulfonates made in China were selected to form an oil displacement agent (ODA) solution. The petroleum sulfonate available for crude oil from the Gudao oil field with the ultra-low interfacial tension can be found by drawing an oil/water interfacial tension contour diagram. The results show that the interfacial tension can be lower than 3.6 × 10^?4 mN/m when the active agent is contained with 0.25% Kelamayi petroleum sulfonate (KPS) + 0.225% Anqing petroleum sulfonate (APS) and if the agent reduces water resistance by entering the tiny pore to improve sweep coefficient and oil displacement efficiency. The polymer has no influence on the balanced value of interfacial tension but delays the interfacial tension to reach the balance. Pouring 0.3 pore volume (PV) high-efficient ODA into reservoir can improve 17% oil recovery (OR). Synergistic effects of two types of petroleum sulfonate with low cost to enhance OR will have an excellent prospect for enhanced oil recovery (EOR).     

表面活性剂水溶液与油之间的动态界面张力研究

本文研究了两种表面活性剂(TRS10-80和天津ABS)盐水溶液与煤油之间的界面张力特性,提出了表面活性剂盐水溶液/煤油体系中动态界面张力产生的机理,讨论了表面活性剂对油的增溶作用对界面张力的影响。经过长期预平衡的表面活性剂盐水溶液/煤油体系仍然存在明显的功态界面张力特性。     

MINERAL MATTER AND CLAY-ORGANIC COMPLEXES IN OIL SANDS EXTRACTION PROCESSES

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the bitumen product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed.

The samples were obtained from Suncor's oil sands extraction plant located in Fort McMurray, Alberta. Samples were obtained from throughout the extraction process from the primary froth through to the final diluted bitumen product. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as well as with other techniques such as interfacial tension measurements. The data indicates that high water content products originate, to a great extent, from the presence of a very hydrophilic organic matrix attached to the surface of the clay and heavy metal minerals.     

Rust Preventive Properties of Uninhibited Hydrocracked Base Stock

Abstract

The uninhibited lube oil base stocks, not containing rust inhibitors, were found to have different rust preventive properties. To differentiate between uninhibited base stocks, the ASTM D 665 rust test procedure was modified to slow down the rust formation process and a more accurate evaluation of rust formation was used. The uninhibited hydrocracked base stock was found not as effective as the mineral base stock, the white oil and synthetic polyalfaolefin (PAO) in preventing the rust formation. The hydrocracked base stock was found to be less effective in preventing rust formation and it was also found to have a significantly higher oil/water interfacial tension. A decrease in the oil/water interfacial tension is required to delay the wetting of the metal surface.     

Formation of water-in-diesel oil nano-emulsions using high energy method and studying some of their surface active properties

In this work, formations of water-in-diesel oil nano-emulsions using water/mixed nonionic surfactant/diesel oil system have been studied. The high energy emulsification method was used to form three emulsions using different water contents: 5%, 10% and 14% (v/v) namely; E1, E2 and E3, respectively. These nano-emulsions were stabilized with emulsifiers having different Hydrophilic–Lipophilic Balance (HLB) namely; span 80 (HLB = 4.3), emarol 85 (HLB = 11) and their mixture (SE) with HLB = 10. The effect of water on the droplet size formation has been investigated. The interfacial tension and thermodynamic properties of the individual and emulsifiers blends have been studied. The interfacial tension (γ) measurements at 30 °C were used to determine the critical micelle concentration (CMC) and surface active properties of these emulsifiers. The water droplet sizes were measured by dynamic light scattering (DLS). From the obtained data, it was found that, mean sizes between 19.3 and 39 nm were obtained depending on the water content and concentration of blend emulsifiers (SE). Also, the results show that, the interfacial tension (γ) gives minimum value (10.85 mN/m) for SE comparing with individual emulsifier (17.13 and 12.77 mN/m) for span 80 and emarol 85, respectively. The visual inspection by TEM showed that the obtained results support the data obtained by dynamic light scattering.     

Thermophysical interface properties of crude oil and aqueous solution containing sulfate anions: experimental and modeling approaches

Abstract

Sulfate anion is well-known for being one of the most active agents to be injected into the oil reservoirs and being capable of not only altering the interfacial properties of crude oil but also enhancing the water solution properties in oil recovery. In the current study, the effects of temperature and pressure were studied on interfacial tension (IFT) as well as the adsorption behavior of two different solutions containing sulfate anion using experimental measurements and modeling approaches. Although it was expected that IFT values of the studied systems might decrease as temperature increased due to the improvement in the molecule mobility and solubility of crude oil in water, which consequently might lead to the reduction in its free energy, the reverse trend was observed. The measured dynamic IFT values and adsorption behavior revealed that surface excess concentration of natural surfactants (Г_NS) can be considered as the most effective parameter on interpreting IFT behavior as a function of temperature.     

用界面张力法测定CO2与原油的最小混相压力

采用悬滴法,测定了在模拟地层温度为356.5K、压力为8.54~23.43MPa时的CO₂与原油间的界面张力.实验发现,CO₂与原油间的界面张力随压力的增加近似呈线性下降趋势.对该数据进行了线性回归,并用外推法计算出当界面张力为零时的最小混相压力为24.17MPa,与实验观测达到一次接触混相状态时的压力(23.43MPa)相比,相对误差为3.16%.采用界面张力确定CO₂与原油间的最小混相压力,既可通过直接观测接触混相状态确定,也可利用所测界面张力数据进行估算,操作简单易行,且耗时少.