The Paraffin Crystallization in Emulsified Waxy Crude Oil by Dissipative Particle Dynamics

With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesoscopic dissipative particle dynamics method is used to study themechanism of the crystallization and deposition adsorbed on thewall.The results show that in the absence of water molecules,the paraffin molecules near the substrate are deposited on themetallic surface with a horizontalmorphology,while the paraffin molecules close to the fluid side are arranged in a vertical column morphology.In the emulsified system,more water molecules will be absorbed on the metallic substrate than paraffin molecules,which obstructed the direct interaction between paraffin molecules and solid surface.Therefore,the addition of watermolecules hinders the crystallization of wax near the substrate.Perversely,on the fluid side,water molecules promote the formation of paraffin crystallization.The research in this paper reveals the crystallization mechanism of paraffin wax in oil-water emulsions in the pipeline from the microscopic scale,which provides theoretical support for improving the recovery of wax-containing crude oil and enhancing the transport efficiency.

Experimental research on oil fi lm thickness and its microwave scattering during emulsifi cation

Synthetic Aperture Radar(SAR) plays a major role in identifying oil spills on the sea surface.However,obtaining information of oil spill thickness(volume) is still a challenge.Emulsification is an important process affecting the thickness and normalized radar cross section(NRCS) of oil film.Experiments of crude oil emulsification with C-band fully-polarized scatterometer were conducted combining airborne hyperspectral imaging spectrometer and 3 D laser scanner observation data,to provide experimental parameters and method to support accurate remote sensing monitoring on marine oil spill.It is further proved that through quantitative homogeneous emulsified oil spill experiments,to a certain extent,the NRCS of oil film increased during the emulsification process of crude oil.The backscattering mechanism of crude oil emulsification was explored using a semi-empirical model(SEM);the change of oil film NRCS was modulated by its dielectric constant and surface roughness,in which the dielectric constant showed a dominant effect.The relationship between thickness and NRCS of oil film was studied under two experimental conditions.The differences of NRCS between oil film and adjacent seawater(Δσ~0) and the damping ratio(DR) were found to have a linear relationship with oil thickness,which were best in the vertical polarization mode(VV) at 45° incident angle during the quantitative crude oil homogeneous emulsification process.In the natural emulsification process of continuous oil spill in which oil film was mixed with both crude oil and emulsified oil,an empirical equation of oil film thickness is preliminarily established.The Δσ~0,DR,and the empirical equation of oil film thickness were applied to the marine continuous oil spill incident on a 19-3 oil platform with spaceborne SAR image and successfully explained the distribution of the relative thickness of the oil film.

Hydrophobic and Magnetic Reduced Graphene Oxide Nanocomposite for Emulsified Oil Removal

Magnetic reduced graphene oxide(MRGO) nanocomposite was prepared by the chemical coprecipitation method and applied as adsorbent for removing emulsified oil from oily wastewater. SEM, TEM, XRD, FT-IR, VSM and other analytical methods were utilized to characterize the prepared MRGO. The adsorption performance of MRGO was evaluated under different initial adsorbate concentration, MRGO dosage, temperature, and pH value of the solution. The adsorption kinetics and isotherms were investigated. In addition, the MRGO repeatability was also tested. It was found that almost 65%of emulsified oil were removed by MRGO in the first 15 min. The MRGO adsorption capacity and efficiency for removal of adsorbate reached 335.85 mg/g and 92.52% within 60 min, respectively. The adsorption capacity reduced with an increasing MRGO dosage, while increased with the increase of emulsified oil concentration. The adsorption performance of MRGO in the alkaline environment was lower than that in the acidic environment. The adsorption data could well fit to the pseudosecondorder model. The Langmuir model could well describe the isotherm data. The MRGO adsorption capacity was still more than 236.1 mg/g at the sixth regeneration cycle.

Corn cob modified by lauric acid and ethanediol for emulsified oil adsorption

Corn cob is a naturally renewable material with developed micropore and hydrophobic characteristics, which enables it to show good oil adsorption capacity. In order to improve oil adsorption capacity, corn cob was modified with lauric acid and ethanediol. The structure of raw and modified corn cob was investigated using Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy(SEM), Brunauer-Emmett-Teller(BET) method, thermogravimetric analysis(TGA) and Ze Ta potential analyzer. The effects of p H level, adsorption time, adsorbent dosage, and initial oil concentration on oil absorbency of corn cob were studied. The results indicate that the modification significantly improved the lipophilicity of corn cob, making the modified corn cob with much better adsorption capacity on oil absorbency. Compared with raw corn cob, the maximum saturated adsorption capacity of modified corn cob is 16.52 mg/g at p H 5, and the increasing percentage is found to be 141%, which indicates that the modification causes a better adsorption capacity for oil removal. In addition, due to high oil adsorption capacity, affordable price and low secondary pollution, the modified corn cob could be considered promising alternative for the traditional oil adsorbent to clean up the emulsified oily water.

Development of key additives for organoclay-free oil-based drilling mud and system performance evaluation

Traditional oil-based drilling muds(OBMs) have a relatively high solid content, which is detrimental to penetration rate increase and reservoir protection. Aimed at solving this problem, an organoclay-free OBM system was studied, the synthesis methods and functioning mechanism of key additives were introduced, and performance evaluation of the system was performed. The rheology modifier was prepared by reacting a dimer fatty acid with diethanolamine, the primary emulsifier was made by oxidation and addition reaction of fatty acids, the secondary emulsifier was made by amidation of a fatty acid, and finally the fluid loss additive of water-soluble acrylic resin was synthesized by introducing acrylic acid into styrene/butyl acrylate polymerization. The rheology modifier could enhance the attraction between droplets, particles in the emulsion via intermolecular hydrogen bonding and improve the shear stress by forming a three-dimensional network structure in the emulsion. Lab experimental results show that the organoclay-free OBM could tolerate temperatures up to 220 ?C and HTHP filtration is less than 5 m L. Compared with the traditional OBMs, the organoclay-free OBM has low plastic viscosity, high shear stress, high ratio of dynamic shear force to plastic viscosity and high permeability recovery, which are beneficial to penetration rate increase, hole cleaning and reservoir protection.

表面活性剂对水驱普通稠油油藏的乳化驱油机理

为了研究乳化降黏驱油剂对不同渗透率的水驱普通稠油油藏的驱油效率和孔隙尺度增效机理,选取了烷基酚聚氧乙烯醚(J1)、α-烯基磺酸盐类表面活性剂(J2)、十二烷基羟磺基甜菜碱(J3)、J3与烷基酚聚氧乙烯醚羧酸盐复配表面活性剂(J4)作为驱油剂,开展了4种驱油剂一维驱油和微观驱油模拟实验,明确了乳化降黏驱油剂在孔隙尺度的致效机理。结果表明,降低界面张力对提高驱油效率的作用大于提高乳化降黏率。在油藏条件下,乳化降黏驱油剂需要依靠乳化降黏和降低界面张力的协同增效作用,才能大幅提高驱油效率。乳化降黏驱油剂的乳化能力越强、油水界面张力越低,驱油效率增幅越大。当化学剂乳化降黏率达到95%时,油水界面张力从10^(-1)mN/m每降低1个数量级,化学剂在高渗透和低渗透岩心中的驱油效率依次提高约10.0%和7.8%。乳化降黏驱油剂注入初期通过降低界面张力,使得高渗透岩心和低渗透岩心中的驱替压力分别为水驱注入压力的1/2和1/3,从而提高注入能力。注入后期大块的原油被乳化形成大量不同尺寸的油滴,增强原油流动性,提高驱油效率。乳化形成的界面相对稳定的稠油油滴,能暂堵岩石的喉道和大块稠油与岩石颗粒形成的通道。油滴的暂堵叠加效应,使高渗透和低渗透岩心的驱替压差分别为水驱压差的5.2倍和32.3倍,大幅提高了注入压力,从而扩大平面波及面积。降黏驱油剂驱油实现了提高驱油效率的同时扩大波及范围。研究结果为水驱稠油开发用驱油剂的研发提供参考,为大幅提高水驱普通稠油采收率奠定基础。

稠油乳化黏度测量曲线与乳液特性的关系

稠油化学驱过程中降黏剂浓度对稠油乳化影响明显,通过测量不同浓度降黏剂的稠油乳状液黏度-时间曲线,以黏度、降黏率为指标分析了黏度曲线与乳液特性的关系。结果表明,当降黏剂的浓度远大于临界乳化浓度时,形成稳定O/W乳状液,黏度低、降黏率大于95%。当降黏剂的浓度大于临界乳化浓度时,形成O/W乳状液,而后随着表面活性剂向油相的迁移,油滴聚并、分层。当降黏剂的浓度与临界乳化浓度相当时,乳状液油O/W转化为W/O,黏度大幅度提高。当降黏剂的浓度小于临界乳化浓度时,只能形成W/O乳状液。

纳米膨润土和非离子表面活性剂协同稳定乳化溶剂提高稠油采收率

针对水驱采收率低且经济上不适合热采的稠油油藏,以具有良好稠油降黏作用的混合芳烃为溶剂,通过纳米膨润土和烷基酚聚氧乙烯醚非离子表面活性剂协同作用构建混合芳烃乳化溶剂驱油体系。结果表明:纳米膨润土和烷基酚聚氧乙烯醚可以稳定乳化溶剂时间超过30 d,其协同机制是烷基酚聚氧乙烯醚通过氢键作用吸附在纳米膨润土颗粒表面实现部分疏水改性,促使其牢固吸附在油水界面提高界面膜的刚性强度,从而大幅度提高乳化溶剂体系稳定性;纳米膨润土吸附非离子表面活性剂后发生弱聚集作用,在连续水相中形成密集三维网状结构,提高乳化溶剂体系的体相黏度和界面黏弹性,增强乳化溶剂体系的流度控制能力;纳米膨润土强化乳化溶剂可以提高水驱稠油采收率超过25%,其主要机制是纳米膨润土增强了乳化溶剂的稳定性和流度控制能力,同时依靠乳化溶剂优异的混溶降黏作用,显著提高了稠油的流动能力,从而提高水驱稠油采收率。

乳化沥青提高原油采收率研究进展

乳化沥青具有注入性能好、封堵强度高等优点,作为一种选择性堵剂在油田提高采收率领域比其他化学剂体系更具应用潜力。本文总结了国内乳化沥青堵水体系的开发历程及现场选择性堵水的应用效果。通过调研近年来国内外文献,概述了乳化沥青堵水的作用机理,一种是作为乳液的作用机理,主要是乳液颗粒被变形捕获产生贾敏效应和乳液液滴的机械滞留使水的流动阻力增大;另一种是其分散相也就是乳液破乳后沥青的作用机理,主要是沥青黏附在岩壁上起到的堵水作用。同时,总结了乳化沥青稳定的主要影响因素,包括温度、水相中的电解质浓度和pH值以及分散相中的沥青质,并且论述了各因素影响乳化沥青稳定性的作用机理。最后,详细叙述了乳化沥青应用于油田调剖堵水领域的最新研究进展,研究表明乳化沥青不仅具有优异的封堵效果,还具有独特的封堵选择性。此外,乳化沥青还能与CO_(2)吞吐、泡沫调驱组成复合增产技术进行现场应用,并且指出了乳化沥青应用于调剖堵水领域存在的问题与未来展望。

油基钻井液乳化剂的制备与性能评价

钻井液乳化剂是油井钻探中的重要化学品之一,其性能评价对于钻井工程的成功进行具有重要意义。优秀的乳化剂能确保钻井液的稳定性和流变性能。在选择乳化剂时,应充分考虑其理化性能和体系综合性能,以确保钻井工程的成功进行。本研究以植物油酸、二乙烯三胺、马来酸酐为主要原料,制备了6种乳化剂产品,并对其进行理化性能评价和体系综合性能评价。实验结果显示,乳化剂PF-MOEMUL1、PF-MOCOAT1、PF-MOEMUL2、PF-MOCOAT2满足所有指标要求,在理化性能评价和体系综合性能评价的关键指标上有良好的性能,为钻井工程提供可靠的保证。而乳化剂PF-MOEMUL3、PF-MOCOAT3在倾点和塑性黏度方面未能达到指标要求。可能导致乳液不稳定、流变性能不佳等问题,从而影响钻井工程的顺利进行。通过对钻井液乳化剂的性能评价,对乳化剂的选择和应用提供了有效的参考指导。

环氧棉籽油制备工艺优化及其下游产品研究

旨在为环氧棉籽油的制备及其高附加值利用提供理论依据和技术支撑,分别采用无机强酸催化法和有机酸自催化法对棉籽油进行环氧化,考察了不同酸对环氧化反应的催化作用及乳化剂对环氧化工艺的影响。以环氧棉籽油为原料,采用开环一锅法制备羟基化棉籽油,并将其与己二酸发生酯化反应合成棉籽油聚酯,对产物进行了红外光谱和核磁共振氢谱表征。结果表明:无机酸中浓硫酸对棉籽油环氧化的催化效果最佳,其次是磷酸,有机酸中甲酸效果最优;乳化剂增加了油-水体系的均匀混合,可适当提高产品的环氧值,但需增加破乳工段;棉籽油聚酯中存在酯基,但仍有未酯化的羟基。综上,量化生产环氧棉籽油可优先考虑甲酸为催化剂,通过环氧棉籽油制备羟基化棉籽油,再与多元酸反应可制备棉籽油聚酯,但存在未酯化的羟基。

超声处理制备大豆油体复合乳液及运载β-胡萝卜素研究

本研究以大豆油体为原料,将其作为乳化剂,通过超声技术制备大豆油体复合乳液,优化超声处理条件,并将油体复合乳液用于运载脂溶性生物活性物质。通过对乳液的理化性质研究,揭示超声处理增强油体复合乳液稳定性的机理并考察油体复合乳液对β-胡萝卜素的运载效果。结果表明,通过超声处理成功制备大豆油体复合乳液,乳液氧化稳定性和贮藏稳定性在功率为450 W(10 min)时最好,此时乳液平均粒径为1537 nm,液滴形状呈圆形且分布均匀。傅里叶变换红外光谱结果表明,超声引起的空化效应增加了湍流和剪切力等物理作用,使油体蛋白的多肽链部分打开,蛋白中的氢键网络发生重新排列,蛋白质二级结构发生改变:α-螺旋结构相对含量减少,β-折叠结构相对含量增多。电泳结果表明蛋白质亚基组成没有显著变化,但随着超声强度的增加,增强了外源蛋白在液滴界面的吸附。贮藏结果显示经过功率为450 W的超声处理可以抑制乳液中氧化产物的产生,提高乳液的氧化稳定性。通过超声处理可成功制备大豆油体-β-胡萝卜素乳液,其中在450 W条件下β-胡萝卜素的包封率最高(94.9%),且经过11 d室温贮藏后保留率为81.8%。本研究为大豆油体作为乳化剂运载脂溶性生物活性物质的应用提供参考。

电化学体系下精准曝气对乳化油废水破乳机制研究

电化学体系下曝气对乳化油废水破乳除油具有显著效果,为响应国家“碳中和”政策号召,提出“精准曝气”概念,基于三相三维电极反应工艺,设计了针对曝气条件优化的试验,并进行能耗分析。试验结果表明,曝气强度缩减至1.5 L/min,曝气时间由90 min减少到60 min时,乳化油废水的COD和含油量分别为101 mg/L、4.98 mg/L,满足回注水标准,且达到了降低能耗的目的。利用COMSOL软件模拟乳化油滴聚集过程,探究破乳机制。在电场和气场作用下,加速削弱了油滴水油界面机械强度,促进了乳化油滴破乳、聚结、上浮去除的进程。

油水乳化胶凝作用对蜡沉积影响的定量表征

通过对乳液黏温曲线变化规律进行挖掘,对凝油团形成过程定量表征,推导得出凝油团形成的数学关系表达式,将胶凝过程细化为凝油团形成和黏附两个阶段。通过蜡沉积的温度条件,发现随着沉积管壁的温度降低,凝油团形成系数逐渐增大,胶凝作用逐渐显著,即在沉积初期蜡沉积的厚度迅速增加,这与蜡沉积实验结果相吻合。

乳化油对断奶仔猪生长性能、血清生化指标和血细胞分类计数的影响

本试验旨在探讨乳化油对断奶仔猪生长性能、血清生化指标和血细胞分类计数的影响。选用80头平均体重为(8.43±0.32)kg的25日龄健康“杜×长×大”断奶仔猪,随机分为对照组(基础饲粮中添加2%的大豆油)和乳化油组(基础饲粮中添加2%的乳化油),每组4个重复,每个重复10头仔猪。试验期为28 d。结果表明:1)2组之间断奶仔猪的平均日增重、平均日采食和料重比均无显著差异(P>0.05)。2)与对照组相比,乳化油组的血清总蛋白、白蛋白、尿酸含量和碱性磷酸酶活性显著下降(P<0.05)。3)与对照组相比,乳化油组的血液白细胞、中性粒细胞、淋巴细胞数量及血红蛋白、平均红细胞血红蛋白浓度显著升高(P<0.05)。由此可见,饲粮中添加乳化油对断奶仔猪生长性能没有影响,但可能促进机体蛋白质分解代谢,提高机体的免疫机能。

某作业区乳化油的破乳研究与应用

某作业区在生产运行中产生了大量乳化油,多次加药处理的效果不佳,导致乳化油存量积压,严重影响了生产运行和经济效益。本文分析了乳化油的成分和影响因素,发现胶质、沥青质和固体颗粒是导致乳化油的稳定性强的主要原因。为此进行了药剂筛选、反应条件优化以及药剂复配等实验,结果表明,SW-30和乳化油处理剂对该区乳化油的处理效果较好。用SW-30破乳剂进行处理,脱水量最高达到40.5%。将SW-30与杀菌剂复配使用,可进一步提高破乳效果,脱水量从40.5%增加到47%。现场处理乳化油110m^(3),获得了30.47t净化油,有效解决了乳化油的处置问题。

3种微藻中提取蛋白质的乳化特性

从钝顶螺旋藻(SPP)、小球藻(CPP)和拟微绿球藻(NOP)中分离到3种微藻蛋白,研究pH值(1,3,5,7,9)对其乳化能力和界面性质的影响,比较并评价用SPP、CPP、NOP稳定的DHA藻油乳液的稳定性、流变学特性和形貌结构。结果表明,SPP、CPP、NOP在等电点(pH=3)附近表现出最小的溶解度、乳化活性、乳化稳定性和最大的表面疏水性,NOP和SPP比CPP具有更高的溶解度和乳化稳定性,NOP和CPP具有更好的乳化活性,尤其是NOP。以pH值为7的微藻蛋白溶液为连续相,以油相比例为10%的DHA藻油为分散相,经超声乳化制备成纳米乳液,由显微图像和SEM图像可观察到明显的水包油结构,通过XRD和FTIR证实DHA藻油在3种微藻蛋白中实现成功包埋,DSC和TGA结果证明其热稳定性良好。其中NOP稳定的乳液平均粒径最小,分散最均匀,并且体系的流变特性、表观黏度和贮藏稳定性明显优于CPP和SPP,具备作为优质植物蛋白乳化剂的应用潜力。

MnO_(2)/Ti电催化膜的制备及其处理乳化油废水性能研究

通过简单可控的电沉积方法制备了一种高性能MnO_(2)包覆Ti基电催化膜(MnO_(2)/Ti)。系统地表征了所制备的MnO_(2)/Ti膜形貌、元素含量、价态分布和电化学阻抗以及循环伏安交流测试,并考察了流速和电流密度对MnO_(2)/Ti膜水处理性能的影响。结果表明,MnO_(2)均匀分布在Ti膜表面,电沉积MnO_(2)可以显著提高Ti膜电化学活性,增强Ti膜电催化氧化性能,从而提升Ti膜自清洁能力。在电流密度为10 mA/cm^(2),流速为1.5 mL/min的工作条件下,乳化油的去除率高达91%。此外,MnO_(2)/Ti膜具有良好的稳定性和可重复使用性能。氧化机理表明,MnO_(2)/Ti膜在电催化处理过程中具有直接和间接氧化活性,MnO_(2)涂层可提高Ti膜的直接氧化能力和·OH、O_(2)^(·-)产量。

含双子表面活性剂的新型油相材料制备与性能研究

为了增强乳化炸药的稳定性和爆炸性能,在传统基于失水山梨醇单油酸酯(Span80)和聚异丁烯丁二酰亚胺(T154)的复合油相材料中加入阳离子双子表面活性剂18-2-18,设计了一种新型复合油相材料,并以此制备了乳化炸药,测试了复合油相材料主要性能参数,考察了18-2-18含量对乳化炸药的乳胶基质粘度、内相粒径及爆炸性能的影响。结果表明:加入18-2-18的新型复合油相材料的酸值、水分、粘度、滴熔点等指标均达到工业生产标准;与传统复合油相材料相比,新型复合油相材料中的18-2-18含量为0.7%时,其乳化剂含量从38.0%降低至23.7%,降低了复合油相材料的生产成本;乳胶基质内相粒径由4.00μm减小到1.22μm,提高了乳胶炸药的稳定性;乳化炸药爆速达到5042 m·s^(-1),且20次高低温循环后仍然能够稳定爆轰,爆速为4512 m·s^(-1)。

乳化复合植物油粉对AA+肉鸡屠宰性能、肉品质和肌肉风味物质含量的影响

试验旨在探究乳化复合植物油粉对肉鸡屠宰性能、肉品质和肌肉风味物质含量的影响。试验选用120只1日龄健康AA+肉鸡(公母各半)随机分为2组,每组6个重复,每个重复10只。1~21日龄、22~42日龄肉鸡豆油组饲粮分别添加0.49%、2.45%豆油,植物油粉组饲粮分别使用1.00%、4.30%乳化复合植物油粉替代豆油组饲粮中的豆油,两组饲粮各营养成分含量一致。试验期42 d。结果显示:与豆油组相比,植物油粉组肉鸡42日龄体重、平均日增重显著提高(P<0.05),料重比显著降低(P<0.05);油脂类型与性别的交互作用对肉鸡屠体重有显著影响(P<0.05),公鸡屠体重显著高于母鸡(P<0.05),腹脂率和皮脂厚显著低于母鸡(P<0.05),植物油粉组屠体重和胸肌率显著高于豆油组(P<0.05),腹脂率显著低于豆油组(P<0.05);植物油粉组公、母鸡肌肉肉色(亮度L*、红度a*、黄度b*)、剪切力、滴水损失和蒸煮损失与豆油组相比无显著差异(P>0.05);油脂类型与性别的交互作用对肉鸡肌肉三磷酸腺苷(ATP)含量和胸肌肌内脂肪含量有显著影响(P<0.05),母鸡ATP含量显著高于公鸡(P<0.05),植物油粉组ATP含量显著高于豆油组(P<0.05),公鸡胸肌肌内脂肪含量显著低于母鸡(P<0.05),植物油粉组公、母鸡肌肉肌苷酸含量、其前体物和分解产物含量、肌内脂肪和游离氨基酸含量与豆油组相比均无显著差异(P>0.05)。研究表明,饲粮中乳化复合植物油粉替代豆油可显著提高肉鸡生长性能、屠体重,减少腹脂沉积,对肉品质和风味物质含量没有显著影响。