污水中油滴聚结机理与材料聚结技术研究进展

独到地分析了含油污水中油滴的材料聚结机理与水力聚结机理的区别和联系,综述了油滴的微观聚结行为。从聚结材料的选择与研制、表面改性与适当处理、聚结停留时间、材料聚结中的水力聚结作用4个方面,重点介绍了材料聚结技术的研究和应用。总结了材料聚结除油技术的不足,指出实现材料聚结和水力聚结的有机融合是材料聚结除油技术未来研究和发展的趋势。     

油田采出水聚结分离研究进展

聚结分离具有结构紧凑、使用成本低、处理量大等优点。本文概述了油田采出水的成分和特点以及油田常用采出水处理技术,综述了聚结技术发展历史、聚结机理研究进展、聚结分离装置现状以及聚结数值模拟研究进展,并对聚结机理和设备的研究进行了展望。     

油田采出水中的超滤膜清洗

根据大庆油田特有水质,考察了水力清洗以及不同化学清洗剂、清洗剂浓度、清洗温度和清洗时间的影响下,膜通量的恢复情况,从而确定了最佳的膜清洗方法。     

荧光法测定油田采出水中示踪剂的含量

对示踪剂荧光素性质进行考察,通过对待测水样用KOH调节pH至8,利用荧光法测定油田采出水中示踪剂的含量.该方法简便、快速且灵敏度高,测定值的相对标准偏差在0.167%以内,加标回收率为96.73%～104.00%.     

油田采出水处理技术综述

介绍了油田采出水不同出路采用不同的处理工艺,重点介绍处理水回注、处理水用于热采锅炉给水、处理水外排的处理流程     

油田采出水处理技术现状及发展趋势

油田采出水处理的目的是去除水中的油、悬浮物、添加剂以及其它有碍注水、易造成注水系统腐蚀、结垢的不利成分。所采用的技术包括重力分离、粗粒化、浮选法、过滤、膜分离以及生物法等十几种方法。各油田或区块的水质成分复杂、差异较大,处理后回注水的水质要求也不一样,因此处理工艺应有所选择。研制新型设备和药剂,开发新工艺,应用新技术成为油田采出水处理发展的新趋势。     

聚结除油器改造及处理聚驱采出液效果研究

为解决聚结除油器处理高黏度聚驱采出液中存在聚结原件堵塞,破乳效果下降问题,通过优化聚结材料,设计合理反冲洗系统,开发新型聚结除油器,实现新型聚结材料再生,提高了油株聚并效果。运行结果表明,总来水平均含油365 mg/L,出水平均含油50 mg/L,去除率达到86%;来水平均含悬浮固体75 mg/L,出水平均含悬浮固体30 mg/L,去除率达到60%。     

油田采出水处理技术的研究进展

在油田开采中,采出水的直接排放会对环境造成影响,通常需要经过深度处理后再排放或者回用。而油田采出水含油量高且含有高浓度有机物和悬浮物,处理难度大。水质特性、处理技术以及处理设备等都会对处理效果产生直接影响,因此,有必要对上述问题进行深入研究。本文对现有研究中油田采出水的水质特性、新型的膜分离技术以及气浮工艺进行了总结,分析了各类处理技术研究现状,并对今后发展趋势进行了展望。     

膜技术在油田采出水处理中的应用研究

采用无机陶瓷膜处理设备处理宝浪油田采出水,研究结果表明:处理后的采出水完全能满足宝浪油田注水的水质要求。产出水中的悬浮物含量小于1mg/L。0.1μm膜处理后的采出水中悬浮物含量平均值为0.417mg/L,粒径中值小于1μm;0.2μm膜处理后的采出水中悬浮物含量平均值为0.57mg/L,粒径中值小于1.5μm;产出水中油含量低于检测限;膜清洗周期为85个小时;清洗方法简单;膜通量的恢复率为99.93%。     

稠油油田采出水处理工艺研究与应用

鲁克沁油田是一个注水开发的稠油油田,随着油井注水受效比例增大,提液增产工作量增加,采出水量呈不断上升趋势。为实现油田经济、有效注水,减轻环境污染,降低油田开发成本,进行了采出水生化处理后回注工艺的研究与应用。在采出水处理工艺上,优选"倍加清"4号、7号联合生物菌群,对有机质平均去除率达到96%;进行加药方案优化研究,确定了絮凝剂、除氧剂、杀菌剂等最佳加药方案,现场采出水经处理后,悬浮物、粒径中值、含油、细菌等水质主要控制指标均达标,同时系统运行平稳,实现了合格污水回注。另外,在室内分别进行了注清水和污水后对储层的伤害情况进行研究,确定了清污混注时的最佳混配比,为油田下步清污混注奠定了技术基础。     

聚结技术及其乳化油水分离性能

聚结分离是一种利用油、水两相对材料浸润性的不同而实现乳化液滴聚结长大并最终通过重力沉降实现油水分离的物理方法,这种方法结构可控性好、分离效率高、运行成本低,是乳化油水分离领域的研究热点。本文首先对聚结分离方法进行详细阐述,介绍了聚结分离原理和影响因素;总结了近年来国内外学者对聚结材料表面改性和修饰等方面的研究。通过调控聚结材料的表面具有特殊浸润性,可显著提高油水分离效率;系统介绍聚结分离器的分类及其应用。最后阐述了聚结分离技术在石油化工领域的应用。本文对聚结分离技术进行展望,指出可以进一步研究实际液滴聚结过程和分离效果影响因素,应深入研究分离器在乳化油水分离过程中液滴聚结行为、机理、控制机制将是研究的重点。     

电场作用下双液滴聚合特性

乳状液破乳分离是目前高含水期油田开采过程中难以解决的技术问题,电场破乳方法具有高效清洁等优点,是解决该问题的有效手段。采用数值模拟与试验验证相结合的方法研究电脱水过程中阶跃、斜坡电场诱导下双液滴的聚合与分离特性。结果表明,在斜坡电场作用下,界面张力引起的泵吸作用大于电场力引起的颈缩作用,有利于液滴聚并,且液滴发生二次乳化现象的概率降低。而施加阶跃电场时,一定范围内能够达到液滴破乳的目的,但液滴在聚并过程中易发生二次乳化现象。从电场对连续相影响的角度分析发现,阶跃电场不仅对液滴具有驱动作用,对连续相的影响也较为明显,阶跃电场会增大连续相内湍流作用,不利于电脱水过程。因此,采用斜坡信号诱导液滴聚合能够降低二次乳化现象发生的概率。     

油田设备中硫化亚铁的化学-机械清洗技术

介绍了一种将JY-01除硫化亚铁药剂与机械三维旋转清洗相结合的清洗技术,来解决油田储罐等设备中硫化亚铁清除的问题。该技术清洗速度快,对设备不产生腐蚀,能够有效解决油田设备维修、检修及清罐过程中硫化亚铁自燃带来的重大安全隐患。     

Coalescence behaviour of water droplets in water‐oil interface under pulsatile electric fields

In this research, the deformation of water droplets in sunflower oil-interface under pulsatile electric field was studied experimentally. Three types of coalescence were observed:(i) complete coalescence, (ii) incomplete coalescence and (iii) no-coalescence. The first type is desirable because of leaving no secondary droplets. The second type that produced secondary droplets which caused by necking process, due to extreme elongation of droplets (mostly small droplets), was undesirable; because the small droplets were more difficult to coalesce and remove. The no-coalescence was caused by very fast coalescence and extensive pushing of droplet into the continuous phase. In this work the process was operated with the utilization of a batch cylindrical separator with high voltage system. The lower part of the cylinder was filled with the aqueous phase and its top part was filled with sunflower oil to form an interface between the two phases. The effects of electric field strength, frequency, and waveform types were investigated. It was found that, the ramp-ac waveform was the best waveform, avoiding the production of secondary droplets and in this case the frequency also played an important role.     

Electrostatic enhancement of coalescence of water droplets in oil: a review of the technology

The technology for electrostatic enhancement of coalescence of water droplets in oil emulsions is critically reviewed. Historically, the electrostatic coalescer was invented for the petroleum-related industries in California [US Patent 987 115 (1911)]. Nowadays, this technology is generally considered for the separation of an aqueous phase dispersed in a dielectric oil phase with a significantly lower dielectric constant than that of the dispersed phase. Various designs have been introduced, with most using alternating current (AC) electric fields with mains frequency (50 or 60 Hz). The direct current (DC) electric field has been less common in the past as compared to the AC. In 1981, the concept of pulsed DC electric fields was introduced, together with insulated electrodes [Trans. IChemE 59 (1981) 229–237; UK Patent 217 1031A (1986)]. Since then, this has become more common in the electrocoalescence technology. Pulsed DC and AC fields are especially useful, when the aqueous phase content of the emulsion is high, to prevent short-circuiting between the pair of electrodes. Processing of oil from old wells is a good example, where the volumetric water content could vary significantly. Reported work by some workers indicates the existence of an optimum frequency, which depends on the electrode coating material, its thickness and the liquid emulsion composition. This is however, a contentious issue which has not been completely resolved. The characteristics and geometry of the electrode system (generally cylindrical or plate) influence the performance of the electrostatic coalescer, and are closely related to the type of the applied electric field and the emulsion used. There are basically two types of electrode: uninsulated electrode and insulated electrode. Combination of electrocoalescence and mechanical separation (e.g., centrifugal force) has also been introduced. Heating and the addition of chemicals have been shown to further enhance the electrocoalescence of water droplets. Other methods that can be combined with the electrical treatment are filtration, methods employing high pressure and temperature, and mixing. This review paper also looks at some of the current specific industrial applications using the electrocoalescence technology. Besides the oil and petroleum industries, this technology has potential applications in the edible oil industries such as palm oil, sunflower oil and vegetable oil processing. Most of the currently available equipment is very big and bulky, having a large inventory of emulsion. Therefore, we see the future trend for new developments to be in the direction of inventing small portable devices, incorporating features such as optimum electric fields and combined electrical and centrifugal forces to further enhance the separation of water-in-oil emulsions. Furthermore, a better understanding of the fundamentals of electrocoalescence will enable a better design of the geometry of the electrodes, of the flow field with respect to the electric fields, the type of dispersion used and the type of the applied electric field.     

气田采出水复合除铁、除钙工艺

由预处理环节水质及精馏塔垢分析可知,管线堵塞的主要原因是含铁、含钙量严重超标,导致结垢物堆积在输水设备及管线内部,同时引起垢下腐蚀,影响气田采出水处理设备的正常运行。鉴于绝大多数处理厂仅考虑铁离子的去除,而未考虑Ca²⁺的去除,本文首次在采出水预处理环节对除铁和除钙工艺进行复合,通过筛选适宜的除铁除钙剂,优化加药顺序、加药反应时间、静置时间等参数,开发出适用于气田采出水处理的复合除铁除钙工艺。结果表明,现场加药量为H₂O₂ 500mg/L、NaOH 500mg/L、PAC 50mg/L、PAM 4mg/L,除钙剂与Ca²⁺的摩尔比为1∶1,加药顺序为Na₂CO₃→H₂O₂→NaOH→PAC→PAM,反应时间7min以上,静置5h以上时,气田采出水中的总铁离子含量可由153.24mg/L降至0.3338mg/L,Ca²⁺由5495mg/L降至520mg/L,其中总铁离子降幅为99.8%,Ca²⁺降低了90.54%,矿化度大幅度降低可避免后续环节堵塞,从而保障气田采出水处理系统高效运行。     

旋流分离技术在工业水处理方面的应用

对旋流分离技术在油田中转站水处理同应用的工艺要求、流程及效果进行了详细分析,并结合油田生产实际,介绍了估旋流分离技术的研究与开发中应当注意的问题,最后得出了一些有益的结论。     

Direct conversion of water droplets to methane hydrate in crude oil

Water droplets suspended in a crude oil were converted to methane hydrate by pressurization in an autoclave cell. Droplet size distributions were monitored using a focused beam reflectance method (FBRM) particle size analyzer as the water converted to hydrate. The droplet size distribution did not change significantly during conversion of nearly all the water to hydrate. The preservation of the distribution during conversion indicates that water droplets act as individual reactors and supports a hydrate shell formation model. Water droplet size distributions were measured with the FBRM probe at multiple shear rates in four crude oils (Albacora Leste, Conroe, Petronius, and a West African oil) with various surface tensions and viscosities. The water droplet size distributions, and thus hydrate particle distributions, were found to be lognormal with breadth increasing with mean. A correlation model has been developed to predict the entire size distribution of water droplets in these oils as a function of viscosity, interfacial tension, and shear rate. The model has been extended to represent gas hydrate particle size distributions in oil after conversion.     

Electrocoalescence of binary water droplets falling in oil: Experimental study

The approaching movement and consequent coalescence of binary water droplets falling in stagnant oil and exposed to an external electric field are investigated using a high speed camera. Different situation of the droplets and electric field intensities are applied in the experiments. The qualitative results of the experimental observations are exhibited through the scaled images of the binary droplets snapshots in milliseconds. Furthermore, different approaching trends of the droplets are presented as quantitative plots and discussed based on the theoretical electrostatic and hydrodynamic models. The effect of the applied voltage amplitude, initial distance of the drop pair, and skew angle of the electric field are investigated. The experimental results prove the electrostatic theories; as acceleration in electrocoalescence demonstrated using a stronger electric field as well as closer distance between the droplets. It was also revealed that the skew angle of the electric field decelerates the electrocoalescence until alignment of the droplets.