Effect of organic alkali,n-alkanol,and nonionic surfactant ternary compound system on viscosity reduction of viscous crude oil

To reduce the viscosity of viscous crude oil and flow resistance, the effect of a ternary compound system including organic alkali, n-alkanol, and nonionic surfactants on viscous crude oil viscosity reduction was studied. The results showed that n-alkanol effectively reduced the droplet size of an emulsion and the viscosity of viscous crude oil and improved the fluidity of viscous crude oil. Of the low-carbon n-alkanols, n-pentanol has the best viscosity-reducing effect. The organic alkali avoids the phenomenon of fouling and corrosion caused by inorganic alkali and reacts with the acidic macromolecular components in viscous crude oil to generate alkanolamides, which produce synergistic effects with nonionic surfactants and reduce the interfacial tension between oil and water. In the ternary compound of organic alkali, n-alkanol, and nonionic surfactant, the viscosity reduction effect of viscous crude oil is significantly enhanced compared with that of a single reagent. The viscosity reduction rate of viscous crude oil of the diethanolamine ternary compound system reached 98.1% and was the best choice by experimental validation. It is shown that a reasonable formula of compound system and dosage can significantly reduce the viscosity of viscous crude oil.     

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.     

Mechanism of viscosity reduction in viscous crude oil with polyoxyethylene surfactant compound system

Surfactant can be used to form stable oil-in-water emulsion and reduce the viscosity of viscous crude oil. The mechanism of viscosity reduction was studied for nonionic surfactant alkylphenol polyoxyethylene (9) ether (APE-9) compound systems. The results showed that the viscosity reduction of viscous crude oil by water-insoluble alkylphenol polyoxyethylene (4) ether (APE-4) was higher than sodium dodecyl sulfate (SDS, anionic surfactant) and dodecyl dimethyl betaine (BS-12, amphoteric surfactant) in the binary compound system. The viscosity further decreased by ethanolamine. The interfacial tension (IFT) study showed that when the reduction in IFT was the highest, the viscosity reduction was the highest.     

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%。     

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.     

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。     

稠油地下催化降粘效果影响因素室内实验研究

在模拟油藏条件和不改变目前蒸汽吞吐工艺的条件下,利用胜利油区单家寺油田单六区东块稠油,选择硫酸镍、硫酸钴、硫酸亚铁、硫酸铁、三氯化铁、氯化亚铁和磷钼酸铵等7种可溶性盐作为催化剂配方成分,进行了复配体系筛选,并利用优选出的催化剂体系,研究在地层中对稠油进行催化改性降粘的可行性及催化降粘效果的影响因素.结果表明:特稠油或超稠油体系在蒸汽开采中具有被催化降粘的可能性,不同催化剂体系的催化效果差别很大;催化剂质量分数、催化反应温度和时间共同影响催化剂体系的降粘效果;pH值小于4和含水率为15％～50％的油藏催化降粘效果较好.因此,针对不同原油和开采状况需要选择不同的催化剂体系.     

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.     

Comparative Studies on Synthetic and Naturally Extracted Surfactant for Improving Rheology of Heavy Crude Oil

Effect of surfactants on rheological properties of heavy crude oil obtained from Mehsana Asset, Gujarat, India, were studied. Studies on effectiveness towards flow behavior were made using a surfactant extracted from a tropical Indian plant Madhuca longifolia (Mahua) and nonionic surfactant Brij-30 considering various contributing parameters such as temperature, concentration, and shear rate. Tests were performed at controlled shear rate. At 25°C, 2000 ppm Mahua and Brij-30 addition reduced viscosity of crude oil by 48% and 52%, respectively. Complex and viscous modulus of crude oil decreased significantly due to addition of both the surfactants. FTIR studies of crude-surfactant mixture showed remarkable decrease in concentration of viscosity enhancing groups such as alkanes, alcoholic, and acidic groups indicating the effectiveness of both the surfactants. Naturally extracted surfactant may be used as flow improver for transporting heavy crude oil.     

烷基芳基磺酸盐结构对原油-表面活性剂-碱体系油-水界面张力的影响

采用旋转液滴法测定了在不同碱浓度下自制的3种结构烷基芳基磺酸盐(C19-4S、C19-6S、C19-8S)与大庆六厂原油体系的油-水动态界面张力,分别考察了磺酸盐结构、强碱和弱碱浓度对油一水动态界面张力最小值(DIFT_(min))和动态界面张力平衡值(DIFT_(equ))的影响.结果表明,在各自适宜碱浓度下,3种结构烷基芳基磺酸盐均可使大庆六厂原油-表面活性剂-碱体系的油-水界面张力达到超低值(10~(-3)mN/m);随芳环在烷基芳基磺酸盐长烷链上的位置向烷链中心移动,达到DIFT_(min)、DIFT_(equ)所需的强碱或弱碱的浓度降低、时间缩短.     

壬基酚聚氧丙烯醚硫酸盐-Na2CO3-桩西原油体系的油-水动态界面张力

 合成了壬基酚聚氧丙烯醚硫酸盐(NPPS)表面活性剂。以NaCl质量分数0.5%的盐水为模拟地层水， 分别配制了NPPS、Na₂CO₃及Na₂CO₃-NPPS复配物与桩西原油的混合体系，测定了体系的油-水动态界面张力。结果表明，单独使用Na₂CO₃或NPPS都无法使盐水-桩西原油体系的油-水界面张力降到0.01mN/m以下。采用NPPS与Na₂CO₃复配，协同效应明显，当体系中Na₂CO₃的质量分数大于0.35 %时，仅需质量分数0.0025 %的NPPS，体系油-水界面张力即可以降至10 ^-4 mN/m以下。     

Synthesis and evaluation of an oil-soluble viscosity reducer for heavy oil

To reduce the viscosity of highly-viscous oil of the Tahe oilfield (Xinjiang, China), an oilsoluble polybasic copolymer viscosity reducer for heavy oil was synthesized using the orthogonal method. The optimum reaction conditions are obtained as follows: under the protection of nitrogen, a reaction time of 9 h, monomer mole ratio of reaction materials of 3:2:2 (The monomers are 2-propenoic acid, docosyl ester, maleic anhydride and styrene, respectively), initiator amount of 0.8% (mass percent of the sum of all the monomers) and reaction temperature of 80 °C. This synthesized viscosity reducer is more effective than commercial viscosity reducers. The rate of viscosity reduction reached 95.5% at 50 °C. Infrared spectra (IR) and interfacial tensions of heavy oil with and without viscosity reducer were investigated to understand the viscosity reduction mechanism. When viscosity reducer is added, the molecules of the viscosity reducer are inserted amongst the molecules of crude oil, altering the original intermolecular structure of crude oil and weakening its ability to form hydrogen bonds with hydroxyl or carboxyl groups, so the viscosity of crude oil is reduced. Field tests of the newly developed oil-soluble viscosity reducer was carried out in the Tahe Oilfield, and the results showed that 44.5% less light oil was needed to dilute the heavy oil to achieve the needed viscosity.     

应用降粘剂提高大港稠油油藏水驱采收率

在对大港官109-1断块稠油组成及结构进行分析的基础上,针对油藏高温、高矿化度及水驱采出程度低的特点,研制出一种降粘剂。在含水量大于30%及降粘剂加入量大于1 000 mg/L（占油水总质量）的条件下,能使油水体系形成稳定的O/W乳液,降粘率大于97%,且降粘剂的存在对采出液的破乳脱水没有负面影响。岩心驱油实验结果表明,降粘剂驱油体系比水驱体系稠油采收率提高22%以上,说明使用降粘剂可降低油藏稠油粘度,改善水/油流度比,提高波及系数,明显改善水驱效果。     

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。     

不同浓度组分可控烷基苯磺酸盐弱碱三元体系乳化规律

三元驱油体系在地层运移过程中化学药剂浓度发生变化,使得三元驱油体系与原油乳化特性也发生改变。针对组分可控烷基苯磺酸盐弱碱三元体系在地层运移过程中与原油的乳化特性开展实验研究。结果表明：使用均化仪对体系及原油进行乳化后,组分可控烷基苯磺酸盐弱碱三元体系中聚合物浓度越低,乳化后体系黏度增幅倍数越大;乳化后三元体系界面张力变化不大,Zeta电位小幅下降,乳状液类型以油/水型为主;三元体系乳化析水率、乳化特性变化明显,其原因是表面活性剂的分子结构影响较大,与界面张力及Zeta电位关系不大。正交实验方法分析了组分可控烷基苯磺酸盐表面活性剂、碳酸钠及中等相对分子质量聚合物这3种不同类型化学药剂对组分可控烷基苯磺酸盐弱碱三元体系乳化特性的影响规律。方差分析结果表明：影响乳状液黏度因素由大到小的顺序为：聚合物、弱碱、表面活性剂,当聚合物质量浓度为600 mg/L时,乳状液黏度增幅倍数最大;影响乳化析水率的因素由大到小的顺序为：弱碱、表面活性剂、聚合物,当Na₂CO₃质量分数为0.3%、表面活性剂质量分数为0.3%、聚合物质量浓度为1000 mg/L时,乳化体系在24 h时的乳化析水率最低,乳化特性最明显。     

稠油降粘剂DJH-1

稠油降粘剂ＤＪＨ－１是由表面活性剂和助剂组成的复合体系,它对胜利油田东辛断块,草桥的稠油有较好的降粘作用,本文介绍了ＤＪＨ－１的降粘性能和典型应用实例。     

吉林扶余油田稠油乳化降黏实验研究

针对典型油样进行组分分析,找出原油中影响黏度的主要因素。采用A型水溶性降黏剂进行乳化降黏实验,通过静态评价试验,研究了水溶性A型降黏剂与原油之间形成乳状液的稳定性和粒径分布、油水界面张力、降黏率及洗油率,考察了该降黏剂降黏效果。实验结果表明:原油中蜡含量迭14.7%,高含蜡是影响原油黏度的主要因素;降黏剂浓度越大,乳状液分水率越低,乳状液粒径分布越集中,油水界面张力越低,乳状液越稳定;油水比越大,分水率随降黏剂浓度变化越显著;随降黏剂浓度增大和油水比降低,降黏率逐渐升高,降黏率最高可达91.5%;该降黏剂有较好的洗油效果,洗油率为61.1%。     

Synthesis and Interfacial Behavior of Decyl Methylnaphthalene Sulfonate

Abstract

High purity decyl methylnaphthalene sulfonate (DMNS) surfactant was synthesized. The purity of product was determined by HPLC, and the structure was confirmed by IR, UV, and ESI-MS. The surface and oil-water interfacial activities of DMNS surfactant were studied. The effects of concentrations of the surfactant, alkali, and inorganic salt on the dynamic interfacial behavior of crude oil/Shengli Oil Field/surfactant oil flooding systems were studied, and comparitive studies of systems with strong and buffered alkali were also carried out. Results showed that DMNS surfactant possessed great capability and efficiency for lowering solution surface tension and oil-water interfacial tension. The critical micelle concentration (cmc) was 0.02% and the surface tension at this concentration was 31.61 mN.m^?1. At proper concentrations of the surfactant, alkali, and inorganic salt, the dynamic interfacial tension between the crude oil of the Shengli Oil Field and the surfactant oil flooding system reached a minimum value of 10^?5–10^?6 mN.m^?1 in a very short time (3–20 min) and maintained an ultra-low value (< 10^?2 mN.m^?1) for a long period of time (15–87 min). The crude oil/surfactant systems presented satisfactory interfacial behavior. DMNS has great potential to be used in enhanced oil recovery (EOR) with low cost and high efficiency.     

油溶性ASM稠油降粘剂的研究

针对高粘原油的特性，合成了一种丙烯酸酯—苯乙烯—马来酸酐三元共聚物(ASM)油溶性稠油降粘剂，确定了最佳反应条件，并对降粘性、粘温性，以及与表面活性剂复配后的降粘性进行研究。结果表明，ASM的降粘效果明显，具有较好的开发应用前景。