破乳剂应用与联合站集输工艺运行影响因素探讨

长庆油田原油处理工艺,无论是破乳剂现场应用"端点加药、管道破乳",还是"末端加药、大罐破乳"两种破乳剂投加方式,原理都是原油破乳剂对原油进行化学作用,破坏油水界面膜的稳定,促使油水状态上的分离,再利用油水密度差异与重力作用,在沉降罐内进行沉降处理,从而实现原油与水完全分离的目的。原油处理状况如何,最直接的两个影响因素即为:破乳剂与原油化学作用效果程度和联合站集输系统的硬件条件与集输工艺水平,如温度控制水平、沉降罐容积的大小、产进液量与外输液量的平稳、集输系统运行参数设置是否合理。主要针对长庆油田目前原油脱水处理过程中,集输工艺特性进行认识分析,及破乳剂在现场使用过程中,联合站沉降罐运行状况对破乳剂脱水方面的影响因素进行探讨,在实际生产中提高集输系统的可控性和稳定性,为改进原油脱水过程的控制方案提供技术指导。     

Optimum demulsifier formulations for Nigerian crude oil-water emulsions

The formation of crude emulsion during oil production and processing is a challenge of significant proportions to the oil producers. Studies show that about two third of Nigerian crude oil production is in form of water in oil emulsion. For economic and operational reasons, it is necessary to separate the water completely from the crude oil before transportation or refining.Efficiency of separation of crude emulsions is of major importance to producers. To this end, this study primarily seeks to investigate the formulation of effective demulsifier that can be used to achieve this aim; and in so doing, the optimal separation efficiency attainable by this demulsification process is determined. Six different samples of water and oil soluble demulsifiers were used on two different samples of synthetic emulsion (sample I and II (both water in oil emulsion) from different Nigerian oil fields). The bottle test method was used to determine the percentage water separation for each crude oil emulsion/chemicals (demulsifiers) mixture. The concentrations of the combined six chemicals (demulsifier samples A–F) in the mixture were related to the percentage water separation using response surface methodology central composite design (RSMCCD).Results show that the optimum concentrations of demulsifiers A–F are 59?ppm/39?ppm/29?ppm/20?ppm/29?ppm/13?ppm respectively for crude oil sample I. While 54?ppm/40?ppm/25?ppm/21?ppm/29?ppm/8?ppm respectively were observed as optimum concentration for crude oil II. The combination of these chemical was observed to return better performance than the existing commercial demulsifiers with percentage water separation of 92% and 94% compared to percentage water separation of 87% and 90% returned by one of the currently available demulsifier used in the petroleum industry for crude oil A and B respectively. Hence, the need to carry out optimization analyses on different emulsified crude oil cannot be over-emphasize.     

用动界面张力方法研究原油/盐水界面的性质Ⅰ.原油天然表面活性剂和破乳剂的竞争吸附现象

测定了原油 /盐水的动界面张力 ,比较了在无破乳剂存在时几种体系的动界面张力曲线。证明了原油天然表面活性剂分子渐渐扩散吸附到原油 /盐水界面上 ,当体系中有破乳剂存在时 ,破乳剂分子以竞争的方式扩散吸附到原油 /盐水界面上。用动界面张力方法研究原油天然表面活性剂和破乳剂在原油 /盐水界面的吸附速率对研究原油乳状液的破乳机理和优化破乳条件十分重要。     

电化学方法研究微生物表面活性剂对原油乳状液破乳的作用

选用一种微生物表面活性剂分别与 3种破乳剂GE 189、XE 12 0和XP 12 0复配 ,对模拟原油乳状液进行破乳脱水。结果表明 ,微生物表面活性剂的引入能够明显地提高破乳剂的破乳速率和效率 ,而且当破乳剂的浓度较低时 ,微生物表面活性剂的影响更加明显。通过界面张力的测定 ,证实了微生物表面活性剂和破乳剂之间的协同作用。利用电化学方法测定水 油 水界面的膜电容和膜电阻 ,探讨了微生物表面活性剂对原油乳状液破乳效果的影响机理。结果表明 ,单独使用微生物表面活性剂 ,观察不到膜电容和膜电阻的任何变化 ;微生物表面活性剂与破乳剂复配 ,界面膜电容随时间的升高与界面膜电阻随时间的下降幅度明显大于单独使用破乳剂时的情况 ,也表明了微生物表面活性剂与破乳剂之间的协同效应。而且由于微生物表面活性剂的加入 ,引起膜电容的迅速升高和膜电阻的迅速下降与乳状液破乳脱水速率的加快密切相关 ,说明该种电化学方法用于破乳机理的研究是可行的。     

逆流高压喷射破乳剂加注工艺数值模拟研究

文章分析了目前现有原油破乳剂加注工艺,提出了逆流高压喷射破乳剂加注方式。采用FLUENT对常规破乳剂加注方法和逆流高压破乳剂加注方法注入点流场进行数值模拟分析,结果表明逆流高压喷射破乳剂加注工艺在主管道中可以形成剧烈的紊流漩涡,加剧了破乳剂和乳状液的混合,而常规破乳剂加注方法破乳剂和乳状液几乎呈分层分布,不利于破乳剂均匀分散到乳化膜表面。逆流高压喷射将破乳剂雾化,有利于破乳剂快速分散到乳化膜表面,替代天然乳化剂提高破乳效果。文章还对加注喷管形式进行了仿真模拟,模拟结果表明渐缩式喷管更有利于提高破乳剂的雾化程度,进而提高破乳效果。     

表征化学驱采出液稳定性不同指标的关联性

研究了聚合物、石油磺酸盐及二元复合驱作为驱油剂对孤岛油田采出的原油乳状液稳定性的影响,考察用不同指标表征乳状液稳定性的关联性。结果表明,在60℃、破乳剂TA1031质量浓度为100mg/L时,随各种驱油剂质量浓度的增大,原油乳状液破乳脱水率降低,120min时脱水率由高到低的原油乳状液体系的顺序为石油磺酸盐体系、聚合物体系、二元复合驱体系,对应的稳定性评分SV值逐渐增大,体系的静态稳定性逐渐增强;对应的破乳后水相Zeta电位绝对值、电导率由大到小的顺序为二元复合驱体系、聚合物体系、石油磺酸盐体系;水相中的油滴中值粒径由大到小的顺序为石油磺酸盐体系、聚合物体系、二元复合驱体系。水相的Zeta电位值越负、电导率越高、水中油滴中值粒径越小,原油乳状液的稳定性越强,脱水率也越低,表明表征化学驱采出液稳定性的各指标具有很好的关联性。     

二元驱采原油破乳技术的研究

通过对二元驱表面活性剂和聚合物进行考察,发现由于表面活性剂和聚合物的进入,使原油采出液的的乳化现象加重,导致原油的破乳过程复杂.文中分析了二元驱采对原油的性质、类型及稳定性的影响;对破乳剂进行了实验室筛选和复配;研究出适合二元驱采原油脱水的破乳剂及其配方,可以有效提高二元驱采的经济效益.     

Demulsifier performance at low temperature in a low permeability reservoir

The crude oil in Longdong area is produced in the form of emulsion containing associated oil and water, which needs to be separated before dispatch to end user. Chemical demulsification under high temperature is the most widely used technology to break the emulsions. In this study a rheological method was used to determine the curve of viscosity-temperature and lower limit of temperature was determined. A series of experiments on low-temperature commercial demulsifies were implemented for studying demulsification performance by bottle test method. Mechanism of low-temperature demulsifier was studied by using spinning drop interfacial tensiometer to determine interfacial tension between the crude oil and demulsifier solution by considering the concentration. Turbiscan stability analyzer was used to study the effect of water content, temperature, and demulsifier concentration on emulsion stability. The corresponding relationship between interfacial tension and demulsification was verified through the study of low-temperature demulsifier effect on interfacial tension. Efficient low-temperature demulsifiers AR102, AR901, PR929, and PRC06 were selected. PRC06 was chosen to be the best at 40°C, and when the optimal concentration was 200 mg/L, dehydration rate was 99.51%.     

Synergistic effect of demulsifiers with different structures for crude oil emulsions

In practice, synergetic effect of the interaction between different demulsifiers is often sought for dewatering the water in oil emulsion of crude oil. Surface tension, interfacial tension, interfacial shear rheology and demulsification test was employed to study the synergistic effect of demulsifiers with different molecular structures, one is the strait-chain demulsifier SP31 and the other branch-chain demulsifier AE31. The strait-chain demulsifier SP31 has a lower IFT but a longer balance time compared with the branch-chain demulsifier AE31. The dewatering rate of AE31 is faster than that of SP31 but the separated water after demulsification for 1 h by SP31 is clearer. It is mainly because the branch-chain demulsifier has stronger penetrability at oil/water interface. When the percentage of SP31 is 40～60%, the complex demulsifier of SP31 and AE31 exhibits the synergistic effect of demulsification performance due to the instantaneous relatively low interfacial tension and the strongest capacity to decrease the strength of the oil-water interfacial film.     

多支化原油破乳剂的制备及破乳性能研究

以乙二胺和丙烯酸甲酯为原料,采用逐代分步合成法合成2.0G树枝状底物,再通过环氧氯丙烷与羟值为60mgKOH/g的环氧乙烷环氧丙烷嵌段聚醚进行扩链,制备一种新型多支化原油破乳剂。对合成的2.0G树枝状底物及破乳剂产品采用红外及电位滴定方法进行结构表征,并对破乳剂产品进行破乳性能研究。结果表明:针对PL19-3 WHPD平台模拟原油乳液,在温度为50℃、所制备破乳剂投加量为90mg/L、脱水时间为30min时脱水率可达90%以上;模拟现场条件,与现场在用破乳剂相比,所制备破乳剂表现出更为优异的破乳性能,经处理后的脱出水中油的质量浓度为20.3mg/L,油中水的质量分数为不大于0.5%。     

沥青稳定剂对稠油脱水影响的实验研究

通过瓶试法测试了沥青稳定剂对海上模拟原油产液破乳效果的影响规律.结果表明,单独应用时,多种沥青稳定剂无论对高含沥青原油还是对几乎不含沥青的原油都没有明显破乳作用;但当其与破乳剂联合使用时,沥青稳定剂AS-1可明显提高高含沥青原油乳液的脱水效果,这表明对于高含沥青原油,破乳剂和沥青稳定剂AS-1之间有一定的协同作用;随着沥青稳定剂AS-1加量的增高,其协同破乳剂脱水的效果也逐渐增高,但当加量增加到一定程度后,其协助破乳的效果便不再提高;另外,乳状液的含水量对破乳剂与沥青稳定剂AS-1之间的协同作用的发挥有着重要影响,低含水时有利于AS-1作用的发挥.     

降压脱气对溶CO2原油乳液中水滴稳定性的影响

通过对CO₂在油/水/乳液中的溶解度、溶CO₂原油的流动性、溶CO₂后油-水间的界面特性、溶CO₂原油乳液的稳定性、油-水界面压力变化的测试与计算,分析溶CO₂原油乳液在降压脱气过程中水滴稳定性的变化规律。结果表明：溶CO2原油乳液中,沥青质等界面活性物质能够迅速地迁移并吸附于油-水界面,并微弱提高油相对CO₂的溶解能力,并使得油-水界面张力快速降低,界面弹性模量增大,降低界面扩张损耗角;溶入CO₂能够降低油相黏度,提高水滴沉降速率,使得原油乳液的分油率增大;降压脱气时,水相中CO₂气泡的析出、长大,迫使水滴膨胀,降低界面上活性物质的浓度,减小了油-水界面压力,使得水滴的聚结稳定性变差,增大了原油乳液的分水率。     

用动界面张力方法研究原油/盐水界面的性质Ⅱ.起始界面吸附速率和表观扩散系数的测定

定量地计算了原油天然表面活性剂和破乳剂在原油 /盐水界面形成初始阶段时的吸附速率。结果表明 ,破乳剂的起始界面吸附速率远远高于原油天然表面活性剂的相应值 ;水相盐度、体系温度和破乳剂的浓度对原油 /盐水起始界面吸附速率有明显的影响。另外计算了破乳剂在油相中的表观扩散系数 ,并分析了其影响因素。     

泾河油田原油破乳剂的优选与复配

针对泾河油田原油密度大、非烃及沥青质含量高、脱水困难、破乳剂用量大等问题,测定了6种商品破乳剂对含水20%稠油的脱水效果。单剂破乳剂25-A和HL-1的脱水效果均优于其它破乳剂,破乳温度65℃、破乳剂浓度600 mg/L时的脱水率分别为65.6%和62.5%。复配破乳剂脱水效果明显优于单剂破乳剂,相同条件下,脱水率高出15.7%。通过破乳剂浓度和破乳温度等影响因素的分析得出,泾河油田原油的最佳破乳条件为:破乳剂浓度400 mg/L,复配比例2∶1,破乳温度80℃,沉降10 h后脱水率可达94.5%。     

清水型稠油破乳剂的研制与应用

针对辽河油田稠油破乳污水含油量高的难题开发了一种高效清水型破乳剂。探讨了破乳剂在破乳过程中的清水机理，结合原油的组成特点，运用表面活性剂结构与性能关系，设计并合成了一系列具有不同嵌段数量、嵌段顺序和链段长度的聚醚破乳剂，室内评价与现场应用表明，该药剂不但脱水率高，而且还具有清水能力强的特点。     

原油复配破乳剂的配方设计

研究了水相pH值、非离子破乳剂和助剂对沙轻原油、阿曼原油、杰诺原油、胜利原油乳液稳定性的影响 ,考察了破乳剂与助剂的协同效应。结果表明 :沙轻原油在水相 pH =6～ 7时乳液的稳定性最差 ;破乳剂通过降低界面张力和使沥青质胶团向油相解缔而破坏乳液的稳定性 ;有机小分子助剂改变界面极性环境或增加芳香度使沥青质增溶而破坏乳液的稳定性 ,它们与破乳剂有很好的协同效应     

重质原油电脱盐用破乳剂的合成及评价

重质原油具有胶质和沥青质含量高、氯盐含量高、黏度高和界面膜稳定性好等特点,利用传统的破乳剂破乳时,破乳效果较差。针对重质原油电脱盐破乳,合成了WS系列破乳剂,对其进行了红外光谱表征、羟值和实际相对分子质量的测定以及电脱盐实验评价。结果表明,合成的WS系列破乳剂产率在98%以上,其中WS-5破乳剂对塔河油田重质原油的破乳效果最好;在破乳剂加量60 mg/L、温度155℃、注清水质量8%、搅拌时间4 min、电场强度1100 V/cm、停留时间90 min、三级电脱盐的条件下,原油盐质量浓度由153.2 mg/L降至2.76 mg/L,脱后原油含水量为0.28%。WS-5破乳剂对塔河油田重质原油电脱盐效果比较理想,具有潜在的应用价值。     

滩海油田破乳剂研究与应用

为了解决大港滩海地区联合站外输原油油水界面混浊,原油含水超标,乳化严重的问题,室内对5种不同类型的破乳剂对滩海油田原油的破乳能力进行分析研究,筛选出2种类型的破乳剂进行复配后对复配破乳剂类型、加药浓度、温度等因素进行研究。最终筛选复配出BH-2型破乳剂在60℃加药浓度为100 mg/L的条件下,原油脱水速度快,油水界面清晰,深度脱水效果显著。与目前在用破乳剂相比,现场使用效果明显,外输原油含水率从3%降到0.7%以下,药剂成本节省16%,可节约成本48万元/a,具有较好的推广应用前景。     

环烷酸铁对老化原油破乳的影响及脱铁机理研究

考察了环烷酸铁对油水乳状液稳定性的影响并对老化油的脱铁机理进行了探讨。实验结果表明：随着乳状液中环烷酸铁含量的增加,乳状液中水滴粒径减小,脱水率降低,水中含油量增大,zeta电位负值增大,乳状液稳定性增强。将聚天冬氨酸与乙酸1:1复配,并分别添加50 mg/L的助剂HCl、NaCl及甲醇,均能提高破乳剂BSE-238对老化油的脱铁率和脱水率。利用偏光显微镜和电导滴定法对破乳脱铁机理进行了探讨,证明加入聚天冬氨酸和破乳剂BSE-238 均能促进液滴聚并,降低乳状液稳定性,且络合剂和油中的铁反应生成一种水溶性的离子络合物并随破乳脱水脱出铁,使水溶液电导率增加,电导率变化曲线与对脱铁的络合机理的推测吻合。     

Treatment of Algerian crude oil using REB09305 OS demulsifier

Algerian crude oil was submitted to a treatment procedure using REB09305 OS demulsifier. Temperature, time of contact with charge and centrifugation speed were studied. Separation of water from crude oil was observed with a demulsification ratio of 100% in ambient temperature for 20?ppm demulsifier dose, 1200?rpm and 45?min of centrifugation time. The results obtained in this study showed that REB09305 OS demulsifier can be considered a promising product for the treatment of industrial crude oil and the removal of water from it.