输油管道用聚α-烯烃类减阻剂的研究进展

聚α-烯烃类减阻剂是一种广泛用于输油管道中的化学添加剂,属于油溶性减阻剂,只需要添加很少的量(一般以ppm计量),就可以有效减小油品在管道中的阻力,达到减阻增输的作用,从而显著提高了经济效益。文章中主要对于近年来聚α-烯烃类减阻剂的减阻机理、制备工艺(主要包括聚合方式和后处理方式)、以及主要的专利制备技术的研究进展进行了介绍,并对其在未来的发展前景进行了预测。     

含高比例疏水单体的降阻剂的合成及性能评价

使用3-溴丙烯和N,N-二甲基十八烷基叔胺合成水溶性阳离子疏水单体N,N-二甲基十八烷基烯丙基溴化铵(DOAB),仅使用水作为溶剂,合成了含有高摩尔分数疏水单体的部分水解聚丙烯酰胺型降阻剂,以核磁氢谱和元素分析得到降阻剂的结构为P(AM0.877-AA0.113-DOAB0.01);激光光散射法测得降阻剂摩尔质量为1.22×10~7 g/mol;黏度法测得临界缔合浓度(CAC)为2.8 g/L。测试了不同质量浓度下降阻剂稀溶液(即滑溜水)在不同流速下的摩阻,以清水为空白组计算降阻率,当降阻剂质量浓度为1.3 g/L时,降阻率最高可达72%;在盐水中,滑溜水降阻率下降,通过提高降阻剂质量浓度的方式可以提升降阻率,盐水中的降阻剂质量浓度为2 g/L时,降阻率最高达70.06%。由SEM得知,降阻剂在水中形成的网状结构是聚合物具有降阻性的直接原因。     

浅谈油品减阻剂的发展现状及趋势

油品减阻剂具有用量小、效果显著、对油品性质影响小等优势,因此对减阻剂的研究显得尤为重要,文章主要介绍了油品减阻剂的分类、减阻机理及其影响因素,同时对其发展趋势进行了展望。     

溶剂对聚合物减阻剂流变行为和减阻性能的影响

采用博力飞旋转粘度计测定了减阻剂在不同溶剂中溶液的流变性能,通过减阻剂室内模拟环道评价装置测定了不同溶剂合成的聚合物的减阻率。结果表明,减阻剂属于典型的剪切增稠型非牛顿流体;减阻剂在不同溶剂中溶液的粘度随着温度升高而降低;当环己烷与减阻剂的溶度参数相等时,减阻剂在环己烷中的溶解性能最好。并探讨了剪切增稠流体的减阻机理,分析了不同溶剂合成的减阻剂对减阻性能的影响。     

油溶性减阻剂三元共聚物的合成和表征

在管输油品中加入减阻剂是提高管线输送能力的有效方法。利用本体聚合法,在齐格勒 纳塔催化体系下,对1 辛烯/1 癸烯/1 十二烯进行三元共聚,用室内模拟环道评价装置测定了聚合物的减阻率,采用正交试验法考察了不同的聚合条件对减阻率的影响。结果表明,最适宜的反应条件如下：V（1 辛烯）∶V（1 癸烯）∶V（1 十二烯）为1∶4∶5,主催化剂TiCl4/MgCl2用量015 g,助催化剂三异丁基铝（TIBA）用量15 mL时,减阻率达到5325％。用乌氏黏度计测定聚合物的特性黏数并关联Mark Houwink方程计算出黏均相对分子质量为6 629 759,通过IR、XRD和1H NMR对聚合物进行表征,证明该方法所得聚合物聚合度较高,具有工业价值。     

Synthesis and performance evaluation of a new drag reducer based on acrylamide/12-allyloxydodecyl acid sodium

Hydraulic fracturing with slickwater is a field-proven stimulation technology used in tight reservoirs. Because of the high pumping rate associated with slickwater fracturing, drag reduction (DR) is critical in minimizing pressure drop and the success of oilfield operations. In this paper, a new type of drag reducer (SPR) was synthesized with acrylamide and 12-allyloxydodecyl acid sodium, and its drag reduction performance was evaluated. The results showed that the new drag reducer features low molecular weight, fast-dissolving rate and low interfacial tension. The algorithm of estimating the drag reduction rate of non-Newtonian fluid SPR was proposed and validated. Empirical or semianalytical models for estimating the friction ratio (σ) or friction factor (λ or f) were used to simulate the turbulence behavior of the SPR drag reducer under different Reynolds numbers (Re). The modified Virk's correlation could accurately model the turbulent behavior of the SPR drag reducer. A unified calculation formula was established in this study for different pipe diameters.     

Combined effects of temperature and Reynolds number on drag‐reducing characteristics of a cationic surfactant solution

The drag‐reducing characteristics in the turbulent channel flow of dilute cationic surfactant solution, cetyltrimethyl ammonium chloride (CTAC)/sodium salicylate (NaSal) aqueous solution, were experimentally investigated in a closed loop fluid flow facility at different temperatures. The mass concentrations of the surfactant solution ranged from 75 to 200 ppm, and the temperatures ranged from 15 to 55°C. The cationic surfactant solution showed a great drag‐reducing ability, which was greatly affected by concentration, temperature, and Reynolds number. It was found that there existed a critical temperature T_c in each solution at different concentrations. Above T_c, drag‐reduction level decreases and reaches the behaviour of water flow without drag‐reducing ability. A new temperature parameters T_f, was proposed, and the difference between T_c and T_f can represent the effective temperature range for the drag reduction at a certain Reynolds number. The variation tendency of T_f and T_c with Reynolds numbers can give the guidance of selecting effective drag reduction range to the practical application in the district heating systems (DHS). It was supposed that temperature and shear stress are two kind of energy applied on the surfactant microstructure, which can be helpful to the surfactant network formation or dissociation depending on their values. © 2011 Canadian Society for Chemical Engineering     

表面活性剂添加对歧管式微通道阻力特性的影响

歧管式微通道（MMC）热沉具有热阻小、结构紧凑、冷却液流量小、流速低、沿着流动方向温度分布均匀等优点,但其小尺寸所产生的较大压降却增加了泵功的损耗.本文研究了表面活性剂添加对其阻力特性的影响,实验选用了纯度为95%的阴离子表面活性剂十二烷基硫酸钠（SDS）和纯度为98%的新型绿色非离子表面活性剂烷基多糖苷（APG）作为减阻添加剂,浓度分别为100和300 mg·kg^-1,结果表明阻力减小率与流速和温度有关.在层流区内减阻效果不是特别明显;但是当流体进入紊流区后阻力减小率开始明显增大,尤其是进入充分发展的紊流区后减阻效果大大加强.此外,温度的提升也可增加阻力减小率,但添加SDS后减阻效果的改善却不及APG.通过对两种不同类型表面活性剂的实验比较,发现温度较高时APG比SDS具有更佳的减阻效果.     

Thermo‐responsive polymers for drag reduction in turbulent Taylor–Couette flow

The addition of a small amount of high molecular weight polymer to a solvent can substantially decrease friction losses by approximately 80%. This phenomenon known as drag reduction (DR) is used extensively in oil recovery during hydraulic fracturing and in many other applications to reduce the pumping costs. However, because of long chain length, these polymers get adsorbed on the surface of reservoir, diminishing the effectiveness of fracking. In the current study, a thermo‐responsive polymer, i.e., poly(N‐isopropylacrylamide) (PNIPAM) is investigated as a drag reducing agent (DRA), which collapses reversibly above 33 °C known as lower critical solution temperature (LCST), thereby preventing it from getting adsorbed beyond this temperature. Free radical polymerization was used to synthesize the PNIPAM and a Taylor–Couette (TC) setup with a rotating inner cylinder was utilized for measuring the DR. The effect of concentration, Reynolds number (Re), and temperature on DR were studied and a maximum of 50% DR was observed at 400 PPM concentration. PNIPAM demonstrated significant decrease in DR beyond LCST, validating its thermo‐responsive nature that could be beneficial for DR in oil recovery or in providing a control modality to DR technologies.DR versus temperature for PNIPAM solution (500 PPM) at Re = 100,000 demonstrating responsive behavior with temperature © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44191.     

EP减阻剂在输油管道中的应用

为了有效解决中俄原油管道投产以来满负荷运行问题,满足输量与压力的运行要求,进行了添加EP系列减阻剂现场试验,本次试验对漠河至加格达奇这段管道进行实验研究,试验结果表明:在10×10~(-6)加剂浓度下,漠大线输量可以由2 100 m~3/h增加到2 400 m~3/h,增输率可以达到14.29%,减阻率可以达到21%。添加EP系列减阻剂可以解决漠大线运行瓶颈问题。     

Water‐soluble polymers. LXXXIII. Correlation of experimentally determined drag reduction efficiency and extensional viscosity of high molecular weight polymers in dilute aqueous solution

The extensional viscosity for aqueous solutions of high molecular weight poly(acrylamide) copolymers and poly(ethylene oxide) homopolymers was measured using a laboratory‐designed screen extensional rheometer. A Bingham model was developed to estimate the average local polymer coil extensional viscosity (η_coil). A strong correlation was found between the measured η_coil values and the polymer extensional viscosity predicted by a bead‐spring model. The dilute aqueous solution drag reduction was measured with a rotating disk instrument under conditions minimizing the effects of shear degradation. Extensional viscosity and drag reduction measurements were performed in deionized water and in 0.514M sodium chloride. The relative drag reduction efficiency values (Δ) in both solvents were found to strongly correlate with measured η_coil values. This is the first report of the accurate prediction of drag reduction behavior for a wide range of polymer types in various solvents from the independently measured molecular parameters η_coil and [η]C. The often‐used relative drag reduction efficiency expressed as the product of [η]C and Δ can now be replaced by the absolute drag reduction efficiency [η]Cη_coil. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1222–1231, 2001     

Storage stability and solubility of poly(urea‐formaldehyde) microcapsules containing A‐olefin drag reducing polymer

Microcapsules containing α‐olefin drag reducing polymer were prepared by in situ and interfacial polymerization with urea, formaldehyde, and styrene as shell materials, respectively. IR spectrums of prepared shells indicated the formations of poly(urea‐formaldehyde) and polystyrene in the microencapsulating process. The morphologies of uncoated particles and microcapsules were observed by scanning electron microscopy (SEM) which proved that the α‐olefin drag reducing polymer particles were effectively coated. For the purpose of determining the stability of microcapsules in transportation and storage, the static pressure experiment was carried out and lasted for 6 months. In this process, microcapsules with polystyrene as shell material stuck together after 3 months; however, those with poly(urea‐formaldehyde) kept the state of particles. The thermal characteristics of uncoated particles (core), poly(urea‐formaldehyde) (shell), and microcapsules with that as shell material were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) which proved that thermal stable temperature of microcapsules containing α‐olefin drag reducing polymer with poly(urea‐formaldehyde) as shell material was below 225°C, and the mean heat absorbed by microcapsules in the temperature increasing process was 1.5–2.0 W/g higher than that by cores. The evaluation of drag reducing rate of microcapsules showed that the microencapsulating process had no influence on the drag reduction of α‐olefin drag reducing polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

天然气减阻剂减阻机理探讨

对现有天然气减阻剂减阻机理进行了较深入的分析,重点介绍了光滑减阻、粘弹减阻和光滑一粘弹减阻机理。从微观结构分析了输气管道近壁区阻力的成因,进一步证实了输气管道近壁区是实现湍流控制和减阻增输的关键区域;从实验研究和理论研究两方面对各个减阻机理进行了评述,并列举了各减阻机理的理论依据或事实依据。此外,简要介绍了天然气减阻剂的应用条件,并提出了减阻机理的研究重点。     

减阻型纳米流体在圆管内的流动和换热特性

实验测定了在Reynolds数4000～16000范围内,质量分数0～0.5%的石墨、多壁碳纳米管、Al₂O₃、Cu、Al、Fe₂O₃、Zn纳米粒子加入到100～400 mg·kg^-1浓度的十六烷基三甲基氯化铵(CTAC)减阻剂中所制备的减阻型纳米流体的摩擦阻力系数和对流传热系数。结果表明:在CTAC中加入水杨酸钠(NaSal)与去离子水所配制的减阻剂具有一定的稳定性和很强的减阻特性,当减阻剂浓度为200 mg·kg^-1时其减阻特性最优。石墨纳米粒子在增强对流换热和减少流动阻力方面具有较佳的综合性能,当石墨纳米颗粒质量分数为0.4%时,其综合性能因子K是去离子水的5倍。最后给出了减阻型石墨纳米流体在圆管内的流动阻力和换热关联式,其计算值和实验值吻合良好。     

表面活性剂添加对气液两相流摩阻压降特性的影响

研究了表面活性剂添加对水平管内气液两相流摩阻压降特性的影响.实验中选用了环境友好的纯度为95%的十二烷基硫酸钠(SDS)作为减阻添加剂,浓度为100 mg•kg^-1.结果表明阻力减小率与流型有关,分层流型的阻力减小率可达83.3%、塞状流型和弹状流型的阻力减小率可达83.2%、环状流型的阻力减小率可达31.2%.表面活性剂可以通过改变液体物性和改变流型两个方面来影响气液两相流摩擦压降.     

Bio-polymers for improving liquid flow in pipelines—A review and future work opportunities

Several decades following Tom's discoveries on polymeric drag reducing agents (DRA) continue to see research efforts to produce robust and shear-stable DRA. Most efforts revolve around established artificial polymers, but questions have been raised recently about their environmental impact and safety. As such, a large number of researchers are looking into natural materials especially bio-polymers as substitutes. Several bio-polymers are found to exhibit drag reducing capabilities in aqueous media. All these factors suggest that bio-polymers would make a suitable alternative to artificial DRAs. This paper aims to present several works to-date on bio-polymer DRAs, and expose new possibilities.     

溶液聚合制备油溶性减阻剂中溶剂的选择和聚合产物性能的表征

依据溶度参数理论预测溶剂和聚合物的相容性,为合成具有更高分子量的减阻聚合物提供理论指导。实验结果表明,使用脂肪烃溶剂（正己烷、正辛烷和环己烷）和芳香烃溶剂（甲苯、苯和氯苯）合成减阻剂黏均分子量的大小顺序与依据溶度参数理论预测不同溶剂合成减阻剂的分子量大小顺序吻合。脂肪烃溶剂是α-烯烃聚合的良溶剂,芳香烃溶剂是α-烯烃聚合的不良溶剂。良溶剂中环己烷是α-烯烃聚合的最佳溶剂,易合成分子量较大的减阻剂。同时,通过室内环道评价装置及XRD和1H-NMR测试手段对聚合产物的结构和性能进行了表征。     

长链α-烯烃本体聚合制备油溶性减阻剂的研究

以负载型TiCl4/MgCl2为引发体系,在微正压条件下采用本体聚合法引长链α-烯烃聚合,制备高减阻性能的油溶性减阻剂(DRA).采用正交试验法考察了各项因素对聚合反应的影响,最终确定最优化的工艺条件.聚合物环道减阻测试的结果表明,在环道中添加的质量浓度为0.01 kg/m3时,减阻率高达55％.用乌氏粘度计测定了特性...     

Synthesis,Characterization, and Application of Zn–Al Layered Double Hydroxide as a Nano-Sorbent for the Removal of Direct Red 16 from Industrial Wastewater Effluents

In this research, nano-structured zinc–aluminum layered double hydroxide (Zn–Al LDH) was successfully synthesized by a co-precipitation method and followed by thermal treatment. The structure and morphology of the obtained material was characterized by X-ray diffraction, transmission electron microscopy, nitrogen-adsorption–desorption isotherms, and Fourier transform infrared spectroscopy. The as-prepared LDH was applied as a solid phase extraction (SPE) sorbent for the removal of direct red 16 (DR16) from aqueous solutions. A spectrophotometric method was used for monitoring of the extracted DR16 at λ = 548 nm. The effect of several parameters such as pH, sample flow rate, amount of nano-sorbent, elution conditions, and sample volume on the removal percentage was investigated. The results showed that DR16 could be retained by Zn–Al(NO₃^?) LDH at pH 6 and stripped by 2.5 mL of 1.0 mol L^?1 NaOH. In the optimum experimental conditions, the limit of detection and relative standard deviation were 0.003 µg mL^?1 and 1.2%, respectively. The calibration graph using the presented SPE system was linear in the range of 0.01–2.00 µg mL^?1 of DR16 with a correlation coefficient of 0.9994. The method was successfully applied for the removal of DR16 from several industrial wastewater effluents.     

Drag reduction in co-current down flow packed column using xanthan gum

Drag reduction is one of the most important techniques for reducing energy consumption in a packed bed contactor. The present work involves an experimental investigation on flow regime transition for air-water system with and without drag reducing agent (DRA), two-phase pressure drop, friction factor and drag reduction using xanthan gum as DRA. Drag reduction was quantified from the two-phase pressure drop data. Based on the present observations it was found that the percentage drag reduction increases with an increase in the concentration of DRA and it is only effective in the range of 300 ppm to 800 ppm. The experimental results indicate that a maximum of 80% drag reduction was achievable using xanthan gum (800 ppm) as DRA. Furthermore, the experimental data were validated with the available literature correlations.