原油乳状液的稳定性及新型破乳剂的研究

介绍了原油乳状液的形成条件,分析了原油乳状液中的天然乳化剂,如沥青质、胶质、石蜡及固体黏性颗粒对乳状液稳定性的影响,概括了破乳剂的破乳机理及几种研究应用较多的新型破乳剂.     

原油乳状液的稳定与破乳机理研究进展

综述了原油乳状液中天然表面活性物质 ,如沥青质、胶质、固体颗粒物以及石蜡对原油乳状液稳定性的影响。讨论了原油破乳机理和破乳剂组成、HLB值等物化性质、破乳剂用量、复配与原油破乳脱水的关系。同时介绍了目前国内使用较多的几个系列破乳剂。     

pH值对原油乳状液稳定性的影响

研究了pH值对原油乳状液稳定性的影响, 测定了胶质和沥青质在油水界面上的聚集和铺张情况, 不同pH值下油水界面张力以及胶质和沥青质模拟乳状液的稳定性变化, 并且完成了不同pH值下的乳状液化学破乳以及电场破乳实验。沥青质相对胶质更易在界面上聚集和铺展, 形成高黏弹性的界面膜。pH值为酸性或碱性时都能有效降低油水界面张力, 增加乳状液稳定性, 使其化学破乳脱水困难, 而破乳实验也验证了这一观点。随着pH值从2增加到10, 胶质模拟乳状液和沥青质模拟乳状液稳定性变化大, 变化趋势则刚好相反, 胶质模拟乳状液稳定性增加, 油水分离速度减慢;沥青质模拟乳状液稳定性减弱, 体系电导率0.21～1.8mS/cm。因此pH<7时, 沥青质稳定能力强, 而胶质稳定能力弱, 电脱水过程中电脱装置正常工作;pH>7时, 结果相反, 表明电脱装置短路现象与沥青质、胶质稳定能力变化相关。     

轻质原油采出液低温破乳剂优选及作用机理

低渗透油田原油属轻质原油，针对低渗透油田采出轻质原油乳状液破乳难度大，低温（<60℃）条件下常规破乳剂破乳效果不佳的问题，根据某油田现场采出液制备模拟乳状液，并分别采用瓶试法、稳定性分析仪研究不同类型破乳剂的破乳效果以及乳状液的微观动力学变化特性，优选出较佳低温破乳剂配方；应用界面流变仪等探讨油水界面黏弹性、油水界面张力、破乳剂在油水界面的动态吸附规律，揭示低温破乳剂的作用机理；最后，分析模拟现场采出乳状液破乳状态，从乳状液脱水率、挂壁程度及破乳剂质量浓度等多个角度综合评价了不同类型破乳剂的低温破乳效果。为低渗透油田采出液低温破乳工艺技术的研发提供了理论及现场应用基础。     

破乳剂对原油乳状液界面膜作用机理研究进展

本文论述了原油破乳机理,同时综述了破乳剂对原油乳状液界面膜作用的研究进展.针对破乳剂在油水中的分配与破乳效果的研究现状以及原油破乳界面特性的研究现状,分析了影响原油乳状液稳定性的因素.     

胜利孤岛注聚原油破乳剂的筛选与性能评价

以研究孤岛注聚原油乳状液破乳为目的,通过瓶试法和界面性质的测定,筛选了多种类型的原油破乳剂,考察了破乳剂质量浓度、聚合物和原油组分对破乳效果的影响,探讨了原油乳状液的破乳机理。结果表明,破乳剂BF-069质量浓度在100mg/L,50℃条件下,脱水率达到70%以上,现场温度稍微升高,脱水率达到85%左右,破乳剂BF-069已在胜利油田应用,现场使用效果良好;聚合物质量浓度在50mg/L时,原油乳状液最难破乳;原油中不同组分对破乳效果的影响不同,油水界面性质的测定表明,胶质和沥青质是影响原油破乳的主要因素。     

沥青质和胶质对辽河稠油乳状液破乳的影响

针对辽河曙光稠油乳状液粘度大、破乳难、破乳温度高等问题,以曙光稠油为研究对象,从中分离出沥青质和胶质,用傅里叶变换红外光谱法分析其主要官能团,考察沥青质和胶质对稠油乳状液粘度及破乳效果的影响。测定了不同含量胶质、沥青质对稠油油／水界面张力的影响。结果证实,沥青质比胶质含有羟基多,分子间氢键作用强烈,更容易造成原油粘稠。随着叫（胶质）、训（沥青质）升高,稠油乳状液脱水率降低,w（沥青质）超过2．1％,或w（胶质）超过32％时,稠油乳状液的破乳十分困难。w（胶质）、w（沥青质）的增高会使破乳剂水溶液与原油的界面张力增大,w（沥青质）增加0．7％比叫（胶质）增加7％原油的界面张力升高还要大,所以训（沥青质）的增加对油水界面张力影响更大。     

油田原油破乳剂的作用机理及应用

原油作为我国重要的战略物资,因而其开采备受社会所瞩目。原油在天然表面活性剂的作用下会与水形成稳定的乳化液,这对于原油的提炼开采构成一定的影响,乳状液稳定性越强,破乳难度越大,原油开采提炼难度越大。由此各种原油乳状液破乳技术不断被研究开发并投入到实践应用。对此,从原油破乳剂的作用机理、影响乳状液稳定影响因素等方面进行分析,对原油破乳剂的主要类型、应用特定和研究进展现状进行阐述,归纳总结当前原油破乳剂的研究进展。     

热采用防乳破乳剂的研究与应用

稠油在热采高温作用下,容易在油层中发生乳化行为,形成稳定的油包水乳状液,给地面产出液处理流程造成一定的负担。通过分析热采放喷后产出液的含水率为28%、脱水原油的黏度为2 300 mPa·s、胶质与沥青质含量和为24.33%,从醇类、酚醛树脂类、多烯多胺类、复配类的防乳破乳剂中优选出防乳破乳剂PEC-12,幵分析了破乳温度、防乳破乳剂浓度、乳状液含水率对PEC-12防乳破乳剂破乳效果的影响。结果表明,随着破乳温度从50℃升高至80℃,防乳破乳剂的破乳率从44.6%逐渐升至98.2%。防乳破乳剂最经济有效的浓度为200ppm。乳状液中含水率从20%增至40%时,防乳破乳剂的脱水率从62.5%增至93.8%。矿场试验表明,在注热过程中添加防乳破乳剂是一种能有效抑制稠油反相乳化的有效措施,添加PEC-12防乳破乳剂后,地面处理流程显示油包水乳状液总量降低80%,稠油乳状液破乳效果好,处理负担明显减轻,同时跟地面产出液破乳剂发生了协同破乳作用,使处理后的污水中含油量达到设计要求,满足回注地层的水质要求。     

浅析海上原油乳状液破乳影响因素

探讨了影响原油乳状液稳定性的因素,简要分析了破乳剂的破乳机理。选择两种常用的原油破乳剂进行试验,研究了温度和p H值对乳状液脱稳和脱水的影响,结果显示:温度对原油乳状液破乳脱稳有显著影响,一般情况下脱水率会随着温度的升高而增大但非绝对,温度的影响因破乳剂的不同而异。p H值会通过影响油水界面张力影响破乳脱水效率,当p H趋于中性时油水界面张力趋大、乳状液的稳定性趋弱,此时破乳脱水效果趋好。     

W／O型乳状液破乳技术进展

介绍了近年来W／O型乳状液的破乳技术,包括重力法、离心法、加热法、化学法、电学法、微波辐射法、超声波法、膜法、微生物法、磁处理法、冷冻解冻法、研磨法、润湿聚结法以及针对于沥青质薄膜决定稳定性的W／O型稠油乳化液的新型CO2破乳法,归纳了各种方法的破乳机理和研究现状,并概述了各种技术的应用特点,为其工业应用提供参考。     

Functions of Demulsifiers in the Petroleum Industry

There are an increasing number of crude oil fields that are now producing both crude oil and water emulsions; such fields are both onshore and offshore. These emulsions are formed during oil exploitation due to the presence of natural surfactants, such as asphaltenes and resins. These molecules strongly stabilize the water/oil interface and prevent coalescence of water droplets. As water/oil phase separation is necessary before oil transportation and refining, demulsifiers are used to break water-in-oil emulsions. This review presents the crude oil emulsion formation, factors affecting demulsification of crude oil emulsion such as demulsifier chemical structure, water content, partition coefficient (K_P), and demulsifier concentration. This review also covers the kinetics and mechanism of the demulsification process.     

高频脉冲电场作用下乳状液液滴动力学模型

基于乳状液中液滴在电场中的受力情况的分析，建立了W/O乳状液中液滴振荡固有频率公式，从理论角度分析和解释了高频脉冲电场对W/O乳状液的破乳机理，从力学的角度分析了最佳频率存在的理论基础，并推导出了最佳频率的计算公式。该固有频率与液滴尺寸、界面张力、黏度、温度、密度等有关。为了验证最佳频率公式的可靠性，用正辛烷乳状液进行了室内实验。实验结果表明，理论最佳频率公式的预测结果与实验测得的最佳频率结果吻合，经修正后与白油实验结果也非常接近。     

用黏度法确定原油乳状液的合适破乳温度

使用旋转黏度计考察了油包水(W/O)型原油乳状液体系与原油乳状液加入破乳剂后的体系两者在表观黏度上的差别。分析了产生这些差别的原因,对其中出现的特殊现象给出了合理的解释。通过对比发现2种体系的黏度差值与适宜破乳温度存在一定的关系,并通过实验进一步验证了这种关系,为原油生产中确定适宜破乳温度提供了新途径。     

石油醚W/O乳状液及其液膜稳定性

以破乳率为衡量标准,借助显微镜直接观察,探讨了乳状液含水量、表面活性剂用量、乳化时间、乳化强度等因素对石油醚W/O型乳状液体系稳定性的影响。在实验范围内,乳状液含水量的提高及表面活性剂用量的增加,有利于乳状液的稳定;存在较优的乳化时间20min和乳化强度4000rmin-1。选取脂肪烃、芳香烃、混合烃共6种不同油相制备乳状液,对比其稳定性的差异。此外,还初步考察了石油醚W/O/W液膜溶胀和泄漏问题,结果表明该乳状液膜泄漏率低于3.5%,表观溶胀率约为20%。     

Recovery of Nitrophenols from Aqueous Solutions by a Liquid Emulsion Membrane System

Abstract

The application of liquid emulsion membrane technology to the extraction of nitrophenols from aqueous solutions is discussed. The effects of various parameters such as hydrophilic lipophilic balance of the surfactants, speed of agitation, water volume fraction in the water-in-oil emulsion, treatment ratio, and the concentration of surfactant on the extraction of p-nitrophenol are studied, and a suitable formulation for a liquid emulsion membrane is developed. The same formulation was used to extract o-nitrophenol and 2,4-dinitrophenol, and the results are compared with those of p-nitrophenol. The swelling of the emulsion during extraction is minimized by the addition of cyclohexanone to the membrane phase. The demulsification of the emulsion phase after extraction is also carried out by a chemical demulsification technique. Acetone is used for demulsification.     

操作参数和物性参数对超声波污油破乳的影响

引言 随着以注水为主要手段的二次采油和以注聚合物溶液为主要手段的三次采油技术的广泛应用,在石油开采过程中产生了大量的污油污水,其破乳分离的难度也越来越大,重力分离、离心分离等常规分离方法已经不能满足实际工况的需求[1-2].超声波破乳脱水技术利用了超声波的机械振动、空化及热效应,能够达到较好的油水两相分离的效果,已经成为一项新兴的技术,得到了学者们的广泛关注[3-5].     

原油破乳研究进展

研发原油破乳技术是现代石油工业领域的重要研究方向之一。综述了原油破乳技术在近年所取得的研究进展,重点归纳和阐述了化学破乳、物理破乳和生物破乳法应用于原油破乳中的进展和各自的优势,并对发展工业规模原油破乳技术所需解决的主要问题和未来研究方向进行了探讨。     

Rapid Salt‐Assisted Microwave Demulsification of Oil‐Rich Emulsion Obtained by Aqueous Enzymatic Extraction of Peanut Seeds

Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process that can also provide edible protein. However, the AEE process may form a stable emulsion in most cases, which seriously limits the large‐scale industry applications for producing vegetable oils. In this study, the salt‐assisted microwave radiation demulsification of the oil‐rich emulsion prepared with AEE from peanuts is investigated. The microwave demulsification method is compared with other conventional demulsification methods, including heating, and freezing–thawing. The salt‐assisted microwave demulsification of the emulsions shows a greater free oil yield than conventional heating demulsification. Moreover, the microwave demulsification shows a similar free oil yield in less time than freezing–thawing method. Under the optimal operating conditions of demulsification, the free oil yield can reach 92.3% with CaCl₂‐assisted microwave demulsification for only 2 min. In addition, the oxidative properties and the fatty acid compositions of the demulsified peanut oil are investigated. No significant difference in the fatty acid composition is observed among salt‐assisted microwave, freezing–thawing, and heating demulsified oil. The oxidative properties of the salt‐assisted microwave demulsified peanut oil is better than the conventional heating demulsified oil. Thus, salt‐assisted microwave demulsification provides a quick and effective demulsification method to obtain vegetable oils with high quality. Practical Applications: Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process. To solve the problem of stable emulsion formed during AEE process, the salt‐assisted microwave demulsification of the oil‐rich emulsion prepared with AEE is developed with high efficiency (demulsification for 2 min). In addition, the oxidative properties of the microwave demulsified oil is better than the conventional heating demulsified oil.     

Demulsification of Emulision Liquid Membrane by Wetting Coalescence Materials

Demulsification of emulsified water-in-oil droplets was worked out with the employment of wetting coalescence materials. Demulsification is carried out in conventional stirred-column and packed-column. Among the four kinds of natural fibers and two kinds of inorganic materials tested, natural fiber A, originated from wood shavings was found to give the best performance of demulsification. The demulsification efficiency can exceed 96.5% when demulsification conditions are optimized. The packed-column showed much better performance both in terms of demulsification efficiency and repeated use of the recovered oil phase for extracting cadmium in simulated wastewater. Operating variables governing the demulsification efficiency were investigated.