原油乳状液稳定性研究 Ⅱ.原油成分对原油乳状液稳定性的影响

原血成分的表面活性物质及其细微固体颗粒,在油水界面上相互作用是原油乳状液其有稳定性的主要原因。本文采用简单的方法将原油中众多的物质分成两大类,并根椐它们单独时或混合后对癸烷/水乳状液稳定性作用的特征,将其分别称为原油乳化剂和原油破乳剂。试验表明,原油乳状液稳定性的高低主要取决于所含的这两大类物质的多少和相对比例,其相对重要性可由界面张力定性地反映出来;并且由原油/水界面张力的大小可以定性地评估原油乳状液的稳定性。     

聚合物对原油乳状液破乳效果影响的实验研究

用31种破乳剂对含聚合物W／O型原油乳状液在不同条件下的破乳效果进行了研究,并研制了针对含聚合物原油的破乳助剂。结果表明,聚合物对破乳有明显的抑制作用,而且单独使用31种破乳剂对含聚合物的原油乳状液均不能产生理想的破乳效果;新研制的破乳助剂与优选的破乳剂复配使用,对含聚合物原油乳状液具有较好的破乳效果,脱水率明显提高,水色明显变清。     

Effect of Alkali on Daqing Crude Oil/Water Interfacial Properties

Alkaline-surfactant-polymer(ASP)flooding using sodium hydroxide as the alkali component to enhance oil recovery in Daqing Oilfield,northeast China has been successful,but there are new problems in the treatment of produced crude.The alkali added forms stable water-in-crude oil emulsion,hence de-emulsification process is necessary to separate oil and water.The problems in enhanced oil recovery with ASP flooding were investigated in laboratory by using fractions of Daqing crude oil.The oil was separated into aliphatics,aromatics,resin and asphaltene fractions.These fractions were then mixed with an additive-free jet fuel to form model oils.The interfacial properties,such as interfacial tension and interfacial pressure of the systems were also measured,which together with the molecular parameters of the fractions were all used to investigate the problems in the enhanced oil recovery. In our work,it was found that sodium hydroxide solution reacts with the acidic hydrogen in the fractions of crude oil and forms soap-like interfacially active components,which accumulate at the crude oil-water interface.     

Stability of Water-in-Crude Oil Emulsions: Effect of Oil Aromaticity,Resins to Asphaltene Ratio,and pH of Water

Abstract

The formation of tight water-in-oil emulsions during production and transport of crude oils is a great problem challenging the petroleum industry. Tremendous research works are directed to understanding the mechanism of formation, stabilization, and controlling of oil field emulsions. This article presents experimental results of some of the factors controlling the formation and stabilization of water-in-crude oil emulsions. In this study, asphaltenes and resins separated from emulsion samples collected from Burgan oil field in Kuwait have been used to study emulsion stability. Model oils of resin to asphaltene ratio of 5:1 and toluene-heptane mixtures have been used to study the effect of oil aromaticity on emulsion stability. Results indicate that at low toluene content (below 20%) or high content (above 40%) less stable emulsions are formed. At a threshold value of 30% toluene, a very tight model oil emulsion is formed. The effect of resins to asphaltene (R/A) ratio on stability of model oil has also been investigated. Results reported in this paper show that as the R/A increases the emulsions become less stable. The effect of pH on stability of model oil emulsion made of 50/50 heptane-toluene mixture having R/A ratio of 5:1 have been studied. Experimental results revealed that as the pH of the aqueous phase of model oil increased from 2 to 10, the emulsion became less stable. At high pH, the asphaltene particles are subjected to complete ionization leading to destruction of the water-oil interface and eventually breakdown of the emulsion.     

含聚合物原油乳状液的稳定性研究

通过室内试验的方法，研究含聚合物原油乳状液的稳定性，考察乳状液的制备方法，聚合物浓度、地层水矿化度对油包水和水包油两种类型乳状液稳定性的影响，并从理论上作了探讨。     

High Temperature Thermal Stability Investigation of Paraffinic Oil

The physical and thermal properties of paraffinic oil were investigated at 250-360°C to determine its suitability for use as a heat-transfer fluid. Thermal stability test was conducted at 360°C for a period of 480 hr in a stainless steel high-pressure autoclave. The paraffinic oil offered sufficient thermal stability for a period of about 300 hr and then became unstable resulting in thermal break down or cracking of the oil. Degradation of the oil led to the formation of gases, liquid components, and solid coke of about 5 wt.% of the starting material. The distillation test performed on the liquid components showed that the composition varied from light naphtha to heavy bituminous material.

The paraffinic oil compared favorably with synthetic organic fluids and the typical properties revealed its suitability as a heating fluid in a system with maximum usage temperature of 310°C as indicated by the thermal stability test. Comparative evaluation of the general properties of the tested paraffinic oil with other paraffinic and mineral oils of different product formulations showed excellent agreement. From these results, it is concluded that the paraffin oil sample produced by the local refinery is suitable for use as a potential thermal fluid at temperatures below 315°C, which is quite adequate for many industrial applications.     

回收乳化液中的蜡油新工艺

介绍了氧化沥青尾气利用冷却水吸附冷却，回收高质量乳化油的新工艺，达到将乳化油净化为回炼的蜡油的目的，以此来提高沥青的附加值，经过两年多的实际应用，效果很好。     

反相乳液聚合法制备驱油用高分子表面活性剂

采用反相乳液聚合法,以(NH4)2S2O8-NaHSO3为氧化-还原引发剂,Span80/OP-10为复合乳化剂,十二胺为助乳化剂,将一种阴离子型表面活性单体MS(一种分子中具有耐水解的N-烷基丙烯酰胺结构的磺酸盐型单体)、N,N-二异辛烷基丙烯酰胺疏水单体(DiC8AM)与丙烯酰胺(AM)共聚制得AM-MS-DiC8AM(简称PMD)共聚物。实验结果表明,制备PMD共聚物的较佳条件为:反应温度40℃;反应时间5h;n((NH4)2S2O8)∶n(NaHSO3)=1∶1,w(引发剂)=0.10%(基于总单体);控制Span80/OP-10复合乳化剂的亲水亲油值在5～6之间;AM,MS,DiC8AM的用量(基于聚合体系的质量)分别为23.6%,6.0%,0.4%。在较佳条件下制备的PMD共聚物水溶液具有较高的表面活性、表观黏度和抗盐能力(黏度保留率为62.2%)。     

复合驱提高采收率实验研究

将聚合物、表面活性剂和凝胶进行复配,制得复合驱体系。进行了复合驱驱油实验,同时还对复合驱提高采收率机理以及复合驱体系注入速度进行了研究。结果表明,聚合物驱后再进行复合驱能进一步提高采收率;高渗复合驱体系具有较高的驱油效率,提高采收率为12．51％-15．66％;低渗复合驱体系也具有较高的驱油效率,提高采收率为7．08％-13．06％,提高采收率值均大于聚合物驱的提高采收率值。确定了复合驱体系最佳注入速度,为0．5mL／min。复合驱体系中凝胶的存在,可提高后续水驱的波及系数,从而提高原油采收率。     

Use of Oil-in-water Pickering Emulsion Stabilized by Nanoparticles in Combination With Polymer Flood for Enhanced Oil Recovery

Efficient flooding agents are required to produce additional oil from mature reservoir. In this work, oil-in-water Pickering emulsion systems stabilized using nanoparticles, surfactant, and polymer have been developed and tested for enhanced oil recovery with and without a conventional polymer flood. Stability of nanoparticles in the dispersion of surfactant-polymer solution was tested using zeta-potential before use. Several flooding experiments have been conducted using Berea core samples at 13.6 MPa and temperatures of 313 and 353 K. It has been observed that a combination of 0.5 PV polymer flood with 0.5 PV Pickering emulsion was efficient and have resulted in 1–6% additional oil recovery as compared to 0.5 PV Pickering emulsion flooding alone. The injection of polymer flood have shown to enhance the pressure drop in the core sample after emulsion flooding and considered as an important factor for an additional recovery of oil. The effect of temperature on the viscosity of flooding agents in relation to pressure drop and oil recovery have also been investigated. Viscosity and pressure drop of emulsion flood systems have shown to marginally decrease with increase in temperature. Studies on nanoparticle retention using SEM have shown that nanoparticles were retained in the core sample during emulsion flooding which may be detrimental for permeability of core sample. It is observed that Pickering emulsion flood with polymer flood would be effective for the enhanced oil recovery suitable for matured reservoirs.     

SH降黏剂对郑王稠油油水界面性质及乳状液稳定性的影响规律研究

以郑王稠油采出液为研究对象,配制航空煤油模拟油-水乳状液,研究了滨南利津联合站所用的SH降黏剂（非离子和阴离子表面活性剂复配而成）对油水界面张力、zeta电位、界面扩张流变性和乳状液稳定性的影响,分析了油水界面性质与模拟油-水乳状液稳定性的关系。结果表明,SH降黏剂质量分数由0增至0.05%时,油水界面张力、油滴的zeta电位变化较小,而扩张模量由16.18 mN/m迅速降至4.60 mN/m,弹性模量由13.76 mN/m降至3.54 mN/m,黏性模量由85.12 mN/m迅速降至29.46 mN/m,脱水率由4.4%迅速增至83.1%,此时界面膜强度的减小是影响乳状液稳定性的主要因素,扩张模量越小则乳状液稳定性越差;当SH降黏剂加量由0.05%增至0.3%时,界面张力由48.93 mN/m降至35.50 mN/m,zeta电位绝对值由7.83 mV逐渐降至3.95 mV,扩张模量、弹性模量、黏性模量逐渐增至7.38、6.42、36.52 mN/m,脱水率降至60.0%。SH降黏剂加量在低于0.3%的范围内,扩张模量与模拟乳状液的脱水率有很好的关联,可以用扩张模量表征模拟油-水乳状液的稳定性。     

影响原油乳状液稳定性的因素研究

研究了室内制备油包水型原油乳状液的制备参数(转速、乳化时间)、含水率、水电导率以及温度等因素对原油乳状液稳定性的影响。结果表明,转速对原油乳状液的形成起决定性作用,转速为7000r/min,乳化时间为8min时形成了乳状液,而且转速越大、乳化时间越长,水滴粒径越小,粒径分布越均匀,原油乳状液越稳定;含水率越高,原油乳状液稳定性越差;原油乳状液电导率的大小取决于乳状液中水电导率的大小,能够反映原油乳状液的稳定性。温度升高,原油乳状液的稳定性降低。     

钢板冷轧乳化油的应用

钢板冷轧乳化油具有较好的润滑性能、冷却性能、防锈性能和退火清净性能,实际应用表明完全满足钢板冷轧的工艺要求.     

稠油O/W型乳状液的低温稳定性

绥中36-1稠油50℃与3℃的黏度分别为1251.5与417518.1 mPa·s,在3~60℃范围内表现为牛顿流体,20℃密度为0.953 g/cm³,属重质普通稠油。用非离子型表面活性剂BJN-01作为乳化剂,制备了不同乳化剂加量（0.3%~0.7%）及油水比（8:2~6:4）的稠油O/W型乳状液。采用恒温静置、流变测量和微观影像分析方法,研究了乳化剂加量及油水比对该乳状液低温（3℃）静态及动态稳定性的影响。结果表明,O/W型乳状液3℃的静态稳定性随乳化剂加量的增大而明显提高;油水比6:4和7:3乳状液的分水率随静置时间延长而增大;油水比8:2的乳状液在制备完成后即发生油水两相分离,稳定性较差。在动态剪切2.0 h后,O/W型乳状液均发生了不同程度的聚集与聚并,油水比越高或乳化剂加量越低,聚集与聚并现象越显著。乳化剂加量0.5%、油水体积比6:4时,在动态剪切2.0 h内,O/W型乳状液表现为牛顿流体,3℃下的黏度小于50 mPa·s;乳化剂加量0.7%、油水比7:3的O/W型乳状液3℃下的黏度小于100 mPa·s,具有良好的低温静、动态稳定性,对管道低温采输及停产停输再启动有良好的适应性。     

高粘度原油举升工艺

本文介绍了瓦拉杰拉油田解决稠油开采问题的评价。试验是在３２井和４８井进行的,表中例举了该井的生产数据。根据油井开作参数,决定采用作者研制的稠油降粘剂。     

SV值表征的稠油W/O乳状液稳定性研究

采用灰色关联熵分析法研究了胜利油田典型区块稠油W/O乳状液稳定性与稠油组成(极性四组分、有机杂原子与过渡金属含量)和油品性质(稠油极性组分偶极矩)的关联,结合稠油W/O乳状液液滴的粒径大小分布及稠油极性四组分Zeta电位,分析了乳状液的稳定机理。用SV值表征乳状液稳定性,SV值越大,乳状液稳定性越好。结果表明,极性四组分、有机杂原子与过渡金属含量与乳状液SV值的关联度从大到小分别为:胶质(0.9945)>饱和分(0.9928)>芳香分(0.9901)>沥青质(0.9597),N(0.9993)>O(0.9918)>S(0.9667),Ni(0.9891)>Fe(0.9852)>V(0.9845),胶质、N及Ni含量与SV值的关联度最大,对乳状液稳定性有重要影响。稠油极性组分偶极矩与SV值的关联度依次为:胶质(0.9929)>沥青质(0.9916)>芳香分(0.9796),胶质的偶极矩是影响乳状液稳定性的关键因素。3-12-182区块稠油的极性四组分Zeta电位绝对值最大,W/O乳状液中液滴粒径最小、尺寸分布最集中(0.5~1.5),SV值最大(1026.70),乳状液最稳定。表2参10     

SBS改性乳化沥青储存稳定性研究

SBS改性乳化沥青具有环保、节能、高低温性能优良等特性,在高等级路面的维修与养护中发挥很大的作用。尽管SBS改性沥青有这些优点,但仍然存在难以乳化和不能长时间稳定储存的问题。通过考察制备SBS改性乳化沥青的乳化剂和工艺,研究了适于乳化SBS改性沥青的乳化剂配方,并分析了SBS改性乳化沥青物性与储存稳定性的关系。结果表明,胶体磨间隙不大于1.0 mm、胶体磨转速不小于2400r/min、乳化剂皂液pH值在2~4、改性沥青中SBS质量分数在3.0%~3.5%时,制备的改性乳化沥青储存稳定性较好。改性沥青颗粒粒径和乳液的恩氏黏度对改性乳化沥青储存稳定性影响明显,利用改性乳化沥青的物性(粒度、黏度)与储存稳定性的关系,调节工艺条件,能够得到储存稳定性好的改性乳化沥青。     

高效驱油压裂液的开发与应用

针对长庆油田现用瓜胶压裂液摩阻高、破胶残渣多、回收处理难度大的问题,将超分子化学、胶体化学与油田化学相结合,研发出一种可替代瓜胶压裂液的高效驱油清洁压裂液体系,该压裂液由1.5% XYZC-6稠化剂、0.15% XYTJ-3调节剂组成。XYZC-6是一种以近肽链结构的黏弹性表面活性剂与多组分有机溶剂复合而成的材料,是一种可实时连续混配并能重复使用的增稠剂。XYTJ-3与返排液中的各项离子可形成溶于水的络合物,降低矿化度对压裂液的性能影响。实验表明,该压裂液耐温90℃,抗盐可达100 000 mg/L,具有良好的携砂、减阻性能,并且压裂液破胶彻底,破胶液残渣含量为2 mg/L,破胶液的界面张力可达0.01~0.001 mN/m。高效驱油压裂液在长庆油田靖安区块得以成功应用,产后单井产量是相邻井产量的2倍,返排液经分离沉降等简单处理后即可再配压裂液,末端返排液经处理可用于驱油,变废为宝,实现压裂液"零排放、零污染",大幅度降低了压裂液的环境污染,为压裂液"不落地"技术提供了保障。      

碱/表面活性剂/聚合物对乳液稳定性的影响

研究了碱/表面活性剂/聚合物对乳液稳定性的影响规律,单一的碱、表面活性剂和聚合物对乳液的稳定性有较大的影响;3种化学剂之间存在明显的协同作用,对乳液的稳定性影响很大。含化学剂的乳液照片验证了多重乳状液的存在。     

Stability of the Oil-water Emulsion Formed During Amphiphilic Polymer Flooding

The amphiphilic polymer can greatly improve the stability of produced liquid and thus makes it difficult to treat. It is of great necessity to study the stability of amphiphilic polymer flooding O/W crude oil emulsion. O/W crude oil emulsion tends to be more stable with increasing amphiphilic polymer concentration and decreasing holding temperature. Amphiphilic polymer flooding O/W crude oil emulsion is much more stable, especially when polymer concentration is above critical aggregation concentration. Aggregation formed by hydrophobic groups of the amphiphilic polymer is beneficial to the stability of amphiphilic polymer flooding O/W crude oil emulsions.