O/W型稠油乳状液的静态稳定性评价研究

针对河南油田某井稠油,采用自制的TN-01乳化剂,根据稠油乳化降黏原理及O/W型乳状液的形成机制,研究了乳化剂的类型、含量、乳化方式、搅拌方式、搅拌速度和相体积分数等对O/W型稠油乳状液稳定性的影响.本文初步探讨了在TN-01中加入纳米助剂TN-23对O/W型稠油乳状液稳定性的影响,为纳米材料在稠油乳化降黏中的应用提供了一个可参考的基础数据.     

O/W型稠油乳状液的静态稳定性评价

针对河南油田某井稠油,采用自制的TN-01乳化剂,根据稠油乳化降黏原理及O/W型乳状液的形成机制,研究了乳化剂的类型和含量、乳化方式、搅拌方式和搅拌速度、相体积分数等对O/W型稠油乳状液稳定性的影响,特别是初步探讨了在TN-01中加入纳米助剂TN-23,对O/W型稠油乳状液稳定性的影响,为纳米材料在稠油乳化降黏中的应用提供一个可参考的基础数据.     

乳化稠油中多重乳滴的形成及对乳状液性质的影响

在新滩肯东451区块产出的平均含水58%的稠油(W/O乳状油)中以0.6 mg/g油的加量加入复配乳化剂HATJ72,在50℃搅拌2分钟转相形成的O/W乳状液,含大量复杂的多重乳滴,观测到了以水为最外相的七重乳滴.多重乳滴稳定性差,讨论了影响多重乳滴稳定性的因素:乳化剂及其加量;搅拌强度;温度;Ostwald熟化作用及形成原始乳滴时的油水比.由该区块净化稠油和含水7.2%的塔河稠油加水加乳化剂配制的O/W乳状液中乳滴结构比较简单,绝大多数为W/O/W型.与由肯东稠油加水加乳化剂配制的O/W乳状液相比,肯东含水(58%)稠油加乳化剂转相形成的含水相同(35%)的O/W乳状液,表观黏度较低且黏度较不稳定.简介了获得成功的肯东451站含水稠油乳化降黏集输试验.在含水58%的稠油中按0.6 mg/g油的加量加入乳化剂HATJ72和自由水,转相形成O/W乳状液,输送温度50℃,乳化液滴结构复杂,乳状液稳定性较差,输送至下游5公里处时,管道垂直方向上含水、油、水滴数量、黏度已有很大差异.液滴结构复杂、乳状液稳定性差,是自由水引起的,因此应控制掺水量.     

陈庄稠油乳化降黏试验

稠油乳化降黏技术是采用加剂的方法,将表面活性剂(乳化剂)加入稠油中形成乳状液,添加乳化剂后形成的乳状液的黏度可比稠油黏度降低2~4个数量级甚至更多。针对陈庄稠油,进行了室内实验,配置了一系列O/W型乳化剂,通过HLB法与静态稳定性实验对近20种乳化剂及其复配方案进行了初选。从降黏率的角度出发,对初选出来的9种乳化剂进行优选,最终筛选出了降黏效果好、静态稳定性优的两种复配型乳化剂,即司班80(25.8%)与十二烷基苯磺酸钠(74.2%)复配型乳化剂、司班80(10.1%)与十二烷基苯磺酸钠(89.9%)复配型乳化剂,两种乳化剂的降黏率均在99%以上。     

孤岛稠油乳化降粘剂FH-02应用性能研究

FH-02是加有抗钙镁离子剂的非离子、阴离子表面活性剂混合物。报道了该剂对孤岛稠油的乳化降粘性能。FH-02溶液用孤岛油田回注污水配制,实验温度50℃,根据静置时脱水率和SV值确定乳状液稳定性。孤岛稠油与0.5%FH-02溶液按体积比80/20、70/30、60/40混合时形成稳定性递减的O/W型乳状液,体积比50/50时形成很不稳定的W/O型乳状液,最佳油水体积比为70/30。在该体积比下,0.5%~1.5%的FH-02溶液与孤岛稠油形成稳定性相近的O/W乳状液,FH-02水溶液的最佳质量分数为0.54%;FH-02质量分数由0.1%增至0.5%时,与粘度21230 mPa.s的稠油形成的乳状液粘度由5485 mPa.s降至303 mPa.s,乳化降粘率由74.16%增至98.57%。0.5%的FH-02水溶液与粘度3546~21230 mPa.s的6种稠油形成的乳状液,粘度在82~303 mPa.s范围,乳化降粘率≥97.7%。对于粘度12871 mPa.s的稠油,FH-02的乳化降粘率(98.8%)高于孤岛油现用3种乳化降粘剂(95.7%~96.6%)。FH-02不影响现用4种原油破乳剂的效能。表6参7。     

孤东油田稠油极性四组分测定方法及其乳化特性研究

稠油油藏高效、经济的开发一直是油田企业研究的技术难题之一,胜利孤东油田稠油油藏由于其胶质、沥青质含量均高于国内主要稠油平均值,有其特殊性,开采难度也更大.文章通过大量室内实验,确定了稠油极性四组分(饱和分、芳香分、胶质、沥青质)的测定方法和分离方法,并采用元素分析、红外光谱分析等手段深入研究了稠油极性四组分的乳化特性、乳化剂对四组分乳化特性的影响.研究结果表明,孤东稠油极性四组分乳状液稳定性次序为饱和分＜沥青质＜芳香分＜胶质＜原油,原油中胶质与沥青质分子通过氢键形成的缔合,对原油的黏度有重要影响.乳化剂OP对稠油极性四组分均具有强烈的乳化促进作用,使W/O型乳状液转变为O/W型,达到了乳化降黏效果.     

O/W型稠油乳状液的制备

本文针对河南稠油制备乳状液为研究内容,根据稠油的乳化机理和O/W的制备方法,深入研究了乳化剂的选择以及乳化剂的类型、添加剂、混合方式、搅拌方式和搅拌时间等对乳状液配制的影响,优选出油水乳状液的制备条件,为室内配制乳状液提供了必要的参考。     

稠油乳状液稳定性实验研究

以孤1-孤5稠油为研究对象,依据稠油乳化降粘原理及O/W型乳状液的形成机制,考察了表面活性剂的类型及添加量、温度、油/水比、搅拌方式等因素对稠油乳状液稳定性的影响,筛选出了适合胜利油田孤1-孤5稠油的降粘剂,并为筛选降粘剂复合配方及选择降粘工艺提供了必要的基础数据。     

海上稠油乳状液稳定性影响因素

为配合注蒸汽热采技术用于海上稠油的乳化降黏,用自制的水溶性乳化降黏剂SP(阴-非离子表面活性剂)配制水溶液,将渤海油田海上稠油与表面活性剂水溶液以油水质量比70∶30混合制得O/W型乳状液。研究了矿化度、pH值、温度和SP浓度等因素对乳状液稳定性的影响,以乳化体系在50℃下静置60 min的出水率作为体系的稳定性表征参数,出水率越高、稳定性越差。此外,通过测定表面活性剂溶液和稠油间的界面张力,分析了乳状液稳定性机制。结果表明,矿化度、pH值对乳状液稳定性的影响最大,SP加量次之,温度的影响较小。随着矿化度的增加,界面张力和出水率先降低后增加,当矿化度为55 g/L时,体系的界面张力最小,稳定性最好;钙离子对乳状液界面张力的影响大于钠离子。碱性条件有利于乳状液的稳定。随着SP加量的减少,界面张力升高,乳状液稳定性降低。SP对海上稠油的最佳乳化温度为50数70℃;SP耐温性良好,经300℃的高温处理后仍具有良好的活性,可配合注蒸汽热采技术用于海上稠油的乳化降黏。图9表1参18     

胜利油田陈南稠油的乳化降黏研究

为实现胜利油田陈南联合站稠油的乳化降黏,选取了7 种亲水亲油平衡值在8～18 的表面活性剂,通过测量单一和复配乳化剂对乳状液的脱水率和降黏率,筛选出降黏效果和静态稳定性良好的乳化剂,考察了油水质量比、乳化剂浓度、乳化温度、乳化强度对乳化降黏效果的影响。结果表明,在乳化温度50℃、乳化强度2000 r/min×10 min的条件下,筛选出的25.8% Span80+74.2%十二烷基苯磺酸钠和10.1% Span80+89.9%十二烷基苯磺酸钠两种复配乳化剂与稠油形成的乳状液静置5 h 后的脱水率分别为21.8%和23.0%,剪切速率为100 s^-1时的降黏率分别为99.92%和99.89%;随油水质量比降低,乳状液脱水率增加、黏度降低、稳定性变差;随乳化剂浓度增加,乳状液黏度先降低后增加;随乳化温度降低和乳化强度的增大,乳状液黏度增加;在油水质量比5∶5、乳化剂质量分数1%、乳化温度50℃、乳化强度1000 r/min×5 min 的乳化条件下,可使陈南稠油黏度（50℃）由1964mPa·s 降至35 mPa·s。图6 表3 参11     

Characterization of ternary compound viscosity reducer system on viscosity of viscous crude oil

Based on the theory that viscous crude oil can form stable two-phase oil-water interfacial molecular membrane with surfactant, the oil-water interfacial activity and viscosity reduction of oil-water interface of viscous crude oil were studied for the ternary compound system, including anionic surfactant alpha olefin sulfonate (AOS), weak alkali Na₂CO₃ and four different kinds of nonionic surfactant emulsifying silicon oil (LKR-1023), lauryl diethanolamide (LDEA), isomeric alcohol ethoxylates (E-1306), and polyoxyethylene sorbitan monooleate (T-80). Results showed when lipophilic or hydrophilic nonionic surfactants were used separately in the same compound system. The viscosity of viscous crude oil could be reduced, but the viscosity reduction efficacy was not desirable. However, using LKR-1023, E-1306, and T-80 as nonionic surfactant with mass fraction 1.0%, the viscosity reduction rate of viscous crude oil reaches 98.92%, 98.29%, and 96.87%, respectively. With 1.4% of LDEA, the viscosity reduction rate of viscous crude oil can reach 98.89%. Through all different kinds of the nonionic surfactant tested, oil-in-water (O/W) emulsion under LDEA ternary compound system has been proved to be the most stable with no phase inversion. Therefore, it is promising to improve the viscosity reduction of the super viscous crude oil by selecting the proper surfactant and dosage.     

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.     

乳化稠油堵水技术在高温高盐油藏中的应用

以塔河油田为例,对乳化稠油堵水技术在高温高盐油藏中的应用进行了研究。使用非离子与阴离子乳化剂复配体系,且添加固体粉末提高乳状液黏度和稳定性,筛选出最佳乳化体系:3%CI-18+1%C22SC+4%沥青粉。结果表明,该乳化体系配制的W/O乳状液具有黏度高、耐温抗盐能力强且热稳定性高。物理模拟实验表明,该乳化稠油堵剂具有较好的堵水性能和耐冲刷性能。     

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     

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.     

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     

乳化作用对水驱后残余油膜效果的实验与评价

驱油剂与原油间的乳化能力对化学驱的驱油效率有重要影响。在自行设计的人造残余油膜模型的基础上,筛选活性驱油剂对人造油膜进行驱替试验,实现了对乳化驱油效果的量化,为活性驱油体系的乳化驱油能力提供了评价指标。试验结果表明,驱油剂与原油的乳化过程能有效剥离油膜,适合在高含水阶段进一步提高驱油效率;乳化能力与油膜驱替效率间有很好的正相关关系,驱油剂的乳化能力决定其油膜驱替效率。通过分析证明界面张力并不能作为评价乳化能力的唯一标准,进一步完善了现有的乳化提高微观驱油效率的机理。     

The Formation of Waxy Crude Oil-in-water Emulsions for the Reduction of Pour Point and Viscosity

Waxy crude oil is characterized by high pour point and poor flow properties, which bring great difficulty to the oil exploitation and transportation. In this study, the fluidity of waxy crude oil with the pour point of 47°C was highly improved by emulsification with synthetic formation water used as aqueous phase. It was found that the combination of CAO-35 and sodium oleate was an effective emulsifier mixture to form stable waxy crude oil-in-water emulsion and when the mass ratio of oil to water was 7:3, the optimum composition of emulsifying additives with respect to the total mass of the emulsion was obtained as follows: emulsifier mixture (the mass ratio of CAO-35 to sodium oleate was 8:2) 0.4% (w/w), sodium triphosphate 0.028% (w/w), NaOH 0.05% (w/w), and polyacrylamide 0.15% (w/w). Diverse factors affecting the pour point of the formed emulsion were also studied. It was found that the pour point of emulsion increased as oil content increased and the optimum mixing speed and cooling rate were 600 rpm and 0.5°C/min, respectively. Under the optimum emulsifying conditions, when mixing speeds were 250 and 600 rpm, respectively, by forming O/W emulsions with the oil content of 70%, the pour point reductions were 20 and 25°C, respectively, and the corresponding viscosity reductions were 89.79% and 97.46% (40°C), respectively. Thus the pour point and viscosity of waxy crude oil are obviously reduced by forming oil-in-water emulsion, which is highly promising for the exploitation and transportation of waxy crude oil.     

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。