一种含β-环糊精和孪尾疏水结构的聚合物驱油剂的制备与溶液性能

以丙烯酰胺、丙烯酸、2-O-(烯丙基氧基-2-羟基丙基)-β-环糊精和N-烯丙基-N-十二烷基油酰胺为主要原料,制备一种含大位阻和孪尾疏水基团的新型共聚物驱油剂。该驱油剂表现出较好的增粘(2000 mg·L-1的驱油剂溶液表观粘度可达670.1 m Pa·s)、耐温(80℃下粘度保留率为93.70%)、抗盐(20000 mg·L-1的Na Cl、2000 mg·L-1的Ca Cl2或2000 mg·L-1的Mg Cl2下,溶液的粘度保留率分别为37.80%、35.14%或33.69%)及抗剪切(1000 s-1时,粘度保留率为7.69%)性能。在总矿化度为9964 mg·L-1、温度为70℃时,2000 mg·L-1的共聚物溶液能建立RF和RRF分别为14.39和5.58,可提高模拟原油的采收率达14.87%。     

一种咪唑啉结构疏水缔合聚合物合成与溶液性质

通过自由基胶束共聚法,在氧化还原引发体系下以丙烯酰胺(AM),丙烯酸钠(Na AA),二甲基二烯丙基氯化铵(DMDAAC)及1-(2-N-烯丙基氨乙基)-2-油酸基咪唑啉(NIPA)共聚合成了一种含咪唑啉结构的缔合聚合物。考察了单体配比、p H及引发剂浓度等条件对聚合反应的影响。通过FT-IR、1H NMR分析对聚合物进行了结构表征。实验发现:该聚合物具有较好的耐温性、抗剪切及抗盐性能(120oC:其粘度保留率达28.12%;1000 s-1:其粘度保留率达16.74%;16000 mg/L的Na Cl:粘度保留率为25.99%;2600 mg/L1的Mg Cl2:粘度保留率为22.48%;2600 mg/L的Ca Cl2:粘度保留率为18.10%)。在室内模拟岩芯驱替实验中,该聚合物可提高采收率16.65%。     

AM/AA/APEG/NANB共聚物的合成与性能研究

通过丙烯酰胺(AM),丙烯酸(AA),烯丙醇聚氧乙烯醚(APEG)和N,N-二烯丙基苄胺(NANB)制备共聚物P(AM/AA/APEG/NANB)。确定了最佳反应条件:m(AM)∶m(AA)=6.5∶3,APEG为5 wt%,NANB加量0.2 wt%,pH为7,反应温度40℃,引发剂0.4 wt%。通过IR和1H NMR确定了聚合物的分子结构,并对其进行性能测试。结果表明:2000 mg·L-1的AM/AA/APEG/NANB溶液具有较好的流变性能(120℃,粘度保留率:38.56%;1000 s-1,粘度保留率:17.93%)和抗盐性能(20 000 mg·L-1Na Cl,2000 mg·L-1Mg Cl2或Ca Cl2,粘度保留率分别为22.14%、18.34%和15.33%),且提高采收率可达16.12%。     

一种核-壳缔合聚合物的高效驱油特性研究

油田产出水直接配注聚合物是聚合物驱的发展趋势和必然,基于提升聚合物在产出水中的综合驱油性能的多级结构和超分子效应的思路,以聚酰胺-胺改性并功能化的纳米二氧化硅为核,甲基-N,N-二辛基丙烯酰胺为疏水单体制备水溶性核-壳形缔合聚合物SHPAM;IR、~1H NMR、SEM和TEM表征SHPAM的结构。SHPAM的核-壳结构及疏水基团的缔合效应协同增强高矿化度产出水配制聚合物溶液的增黏性、抗剪切性及长期稳定性能,SHPAM的零剪切黏度是梳形聚合物(KYPAM)的60倍。SHPAM比KYPAM少500 mg·L~(-1),SHPAM有更强的流度控制性能,对岩心渗透率有良好的兼容性;水驱至含水率98%,0.30 PV的SHPAM驱(浓度1500 mg·L~(-1))提高原油采收率达25%。结果表明产出水配注SHPAM表现高效的驱油效率。     

AM/AA/NAPA/NMQS两性离子共聚物的合成及表征

以丙烯酰胺(AM)、丙烯酸(AA)、N-烯丙基苯乙酰胺(NAPA)及N-甲基-N-烯丙基吗啉溴盐(NMQS)为原料,氧化还原体系下合成了一种水溶性两性离子共聚物AM/AA/NAPA/NMQS。最佳反应条件为:m(AM):m(AA)=4.0:6.0,NAPA 0.3 wt%,NMQS 0.15 wt%,引发剂0.1 wt%,pH=6,反应温度35℃,单体总浓度25wt%。对AM/AA/NAPA/NMQS四元共聚物进行了IR、1H NMR、SEM、特性粘数表征。当NaCl浓度为12000mg·L-1,CaCl2或MgCl2浓度为1200 mg·L-1时,溶液黏度保留率分别为13.7%、11.8%和12.7%;温度120℃时,溶液黏度保留率达到30.9%;当剪切速率在170 s-1时,溶液黏度保留率为24.6%。     

纳米埃洛石管对HPAM性能的影响

采用油酸改性纳米埃洛石管(HNTs)将部分水解聚丙烯酰胺(HPAM)与改性HNTs(O-HNTs)共混制备一种稳定的分散体系HPAM/O-HNTs。采用红外和接触角对O-HNTs的化学结构进行表征,并系统考察HPAM/O-HNTs的增黏性、耐温耐盐性、抗剪切性和驱油效果。结果表明：O-HNTs分子链中含有长烷基链、双键等疏水基团,具有疏水作用。加入O-HNTs后,HPAM/O-HNTs黏度明显提高,表现为优异的增黏性。HPAM/O-HNTs在30～90℃的NaCl(0～12000 mg·L^-1)和CaCl₂(0～12000 mg·L^-1)溶液中的黏度均比HPAM高,表现出优异的耐温抗盐性能。90℃条件下,随着剪切速率增大,HPAM/O-HNTs黏度逐渐减小。500 r·s^-1条件下溶液黏度大于17.2 mPa䦆Wingdings 2VB@s,表现出优异的抗剪切性能。在相同条件下,HPAM/O-HNTs的驱油采收率比HPAM高12.3%,驱油效果显著。     

水溶性AM/AA/AOCA/DANA四元共聚物驱油剂的合成及性能研究

以丙烯酰胺(AM),丙烯酸(AA),N,N-二烯丙基-3-吡啶甲酰胺(DANA)和N-烯丙基辛酰胺(AOCA)为单体,采用过硫酸铵-亚硫酸氢钠((NH_4)_2S_2O_8-NaHSO_3)氧化还原引发体系合成了一种新型水溶性四元共聚物AM/AA/AOCA/DANA。确定了最佳反应条件:m(AM)/m(AA)=6:4、DANA=0.16 wt%,AOCA=0.15wt%、pH值7、引发剂0.3 wt%、单体浓度20 wt%、聚合温度50℃。通过红外、核磁氢谱、环境扫描电镜以及特性粘数对AM/AA/AOCA/DANA进行了结构表征。该聚合物较部分水解聚丙烯酰胺相比具有明显的抗温(100℃,粘度保留率:31.55%)抗剪切(1000 s~(-1),粘度保留率:32.31%)以及抗盐性能(11000 mg·L~(-1)NaCl,粘度保留率:41.77%;1500 mg·L~(-1)MgCl_2,粘度保留率:39.83%;1500 mg·L~(-1)CaCl_2,粘度保留率:34.81%;);驱油实验表明该聚合物较水驱相比能够提高原油采收率达12.04%。     

油醇系浓缩缔合聚合物压裂液增稠剂的合成及其性能研究

以丙烯酰胺(AM),2-丙烯酰胺-2-甲基丙磺酸钠(AMPSNa)和甲基丙烯酸十六烷基酯(MPA)为单体[n(AM)∶n(AMPSNa)∶n(MPA)=35∶4.5∶0.5],0.1%过硫酸钾/亚硫酸氢钠为引发剂,于35℃聚合4 h合成了一种疏水缔合聚合物型压裂液增稠剂(AF),其形貌和增稠性能经TEM和流变仪表征。结果表明:AF在水溶液中可形成密集的空间网络结构;CACAF为1 200 mg·L-1。以白油为外相,甲醇为内相,AF为增稠剂,制备了油醇浓缩缔合聚合物压裂液增稠剂CAF,其性能经流变仪和表面张力仪表征。结果表明:0.65%CAF于140℃/170 s-1剪切1 h,表观黏度为77.1 m Pa·s,高温抗剪切性较好;于95℃破胶3 h,破胶液表观黏度,表面张力和残渣含量分别为1.32 m Pa·s,26.9 m N·m-1和25.8 mg·L-1,破胶返排性较好。     

AM/AA/DMDAAC/OAM疏水缔合的两性共聚物的合成及性能研究

以十八醇为原料,制备长链疏水单体N-十八烷基丙烯酰胺(OAM)。以丙烯酰胺(AM)、丙烯酸(AA)、二甲基二烯丙基氯化铵(DMDAAC)、N-十八烷基丙烯酰胺(OAM)为单体,通过胶束聚合法合成了水溶性疏水缔合两性四元共聚物。利用FT-IR、1HNMR、DTA-TG对聚合物的结构和热稳定性进行分析,考察了疏水基团摩尔分数、聚合物浓度对聚合物溶液表观粘度、储能模量、耗能模量等流变性能的影响,并对四元共聚物溶液的性能进行评价。结果表明,疏水两性共聚物具有很好的耐温、抗盐、耐剪切等优异性能。     

反相微乳液中疏水缔合型聚丙烯酰胺的合成及其性能研究

在反相微乳液体系中合成了疏水缔合型聚丙烯酰胺 (HAPAM ) ,用Brookfield旋转粘度计测定了其水溶液性能 ,并与传统胶束聚合法制备的HAPAM作了比较 .结果显示 ,前者有更优越的耐盐和抗剪切性能 ,这主要是因为前者的大分子链上疏水共聚单体呈无规分布而后者呈嵌段分布 ,其疏水分子链以分子间而不是分子内缔合为主     

Interfacial Tension Measurements Between Oil Fractions of a Crude Oil and Aqueous Solutions with Different Ionic Composition and pH

Dynamic and equilibrium interfacial tensions between crude oil fractions and aqueous solutions of various compositions and pH were measured. The basic oil components seemed to determine the interfacial tensions at pH 2, while the non-dissociated and dissociated acidic components governed the interfacial tension at the natural pH and pH 9, respectively. The ionic composition of the aqueous phase influenced the degree of dissociation of the acidic components at pH 9: Na⁺ ions in the aqueous phase promoted dissociation of the interfacial acidic components (compared to pure water), while Ca²⁺ ions resulted in complexation with the dissociated acids and most likely formation of stable interfacial films. The amount of Ca²⁺ determined which of these phenomena that dominated when both ions were present in sea water solutions. Generally, the interfacial tensions of the oil fractions were lower when measured against the high salinity aqueous solutions than against the corresponding low salinity solutions.      

High-molar mass acrylamide-co-diacetoneacrylamide graft copolymers as viscosity enhancer for polymer flooding oil recovery

One of the most widely applied enhanced oil recovery processes is the polymer flooding, in which aqueous solution of polymer viscosifier is introduced in oil reservoirs to increase the recuperation of the remaining oil. From the current challenges of this process, it can be referred to a high cost of materials regarding their substantially required amount and the low impact on the mobility ratio during the process due to the reduction of solution viscosity at high temperatures and high salinity environments. The purpose of this study is to investigate the concept of acrylamide-based thermosassociating copolymer (TAP), with a specific morphology and chemistry (hydrophilic main backbone made of polyacrylamide with grafted amide functionalized pending chains) as viscosity enhancer at harsh conditions of high temperature and salinity. For that aim, a specific TAP microstructure was targeted (very high molar mass linear polymer chains with improved copolymer homogeneity). It is achieved in this study throughout applying the reaction engineering approach, such as synthesis in semi-batch mode or/and in heterogeneous dispersed media. As a result, the synthesized TAP presented excellent behavior as viscosity enhancer especially under high temperature and salinity conditions with improved performance in comparison to TAP synthesized by a conventional solution polymerization approach and to actual commercial high molar mass acrylamide-based polymer.     

Experimental Validation of the Temperature-Resistant and Salt-Tolerant Xanthan Enhanced Foam for Enhancing Oil Recovery

Xanthan enhanced foam (XGF) is a newly developed chemical agent for enhanced oil recovery in high-temperature and high-salinity reservoirs. In this paper, laboratory experiments were performed to characterize the morphology and foam properties of XGF, to study its performance under different temperature and different salinity conditions, respectively. Based on simulate reservoir formation conditions of Xidaliya field, a series of research on XGF were conducted. The experimental results showed that the scanning electron microscopy of XGF reflected a more viscoelastic and stable nature of the foam system. High temperature had a great adverse impact upon the stability of XGF, and the increase of salinity in the solution helped to improve the stability of foam. The foam stability increased remarkably when XG4 is added, and an increase in ambient pressure made enhancement of foam stability became more noticeable. In the presence of crude oil, Xanthan could enhance the stability of emulsions and was more favorable to stabilize foam. XG4 enhanced foam had dramatic properties for mobility controlling and oil displacement in the porous media.     

Application potential of in situ emulsion flooding in the high-temperature and high-salinity reservoir

In this research, an emulsifier formulation named SC-18 for W/O system was screened out and evaluated for feasible application of in-situ emulsion flooding in high-temperature and high-salinity reservoir. Results showed that SC-18 could reduce interfacial tension to 10–2 order of magnitude and change rock wettability from oil-wet to water-wet, which was beneficial to decrease residual oil saturation and improve displacement efficiency. Meanwhile, rheological testing showed that emulsion produced by SC-18 exhibited good temperature tolerance and mechanical stability, which favored mobility control and sweep efficiency enhancement under harsh conditions. In addition, good viscoelasticity of produced emulsions could also improve sweep efficiency by strengthening plugging and diverting effects of emulsion droplets, namely enhancing “Jiamin effects.” By means of natural core flooding and visualized plate model, it was proved that in-situ emulsion flooding with SC-18 could improve both displacement efficiency and sweep efficiency for high-temperature and high-salinity reservoir.     

Protein foam application for enhanced oil recovery

Protein foam was explored as a foaming agent for enhanced oil recovery application in this study. The influence of salinity and oil presence on bulk stability and foamability of the egg white protein (EWP) foam was investigated. The results were compared with those of the classical surfactant sodium dodecyl sulfate (SDS) foam. The results showed that the EWP foam is more stable than the SDS foam in the presence of oil and different salts. Although, the SDS foam has more foamability than the EWP foam, however, at low to moderate salinities (1–3 wt% NaCl), both foam systems showed improvement in foamability. At a NaCl concentration of 4.0 wt% and above, foamability of the SDS foam started to decrease drastically while the foamability of the EWP foam remained the same. The presence of oil has a destabilizing effect on both foams but the EWP foam was less affected in comparison to the SDS foam. Moreover, increasing the aromatic hydrocarbon compound percentage in the added oil decreased the foamability and stability of the SDS foam more than EWP foams. This study suggests that the protein foam could be used as an alternative foaming agent for enhanced oil recovery application due to its high stability compared to the conventional foams.     

Ion-Chromatographic Determination of Low Concentrations of Nitrate in Solutions of High Salinity

The determination of low concentrations of inorganic anions in water samples of high salinity is one of the most difficult tasks in analytical chemistry. There is, however, an increasing demand for the exact and reliable determination of nutrients even at very low concentration levels in environmental samples of complex composition. We therefore present the development, quality control and application of an easy and rugged method that makes possible the determination of trace amounts of nitrate in solutions with high concentrations of chloride (>30 000 mg L⁻¹) and a hundred-fold excess of bromide ions, based on ion chromatography with UV detection at λ = 210 nm. While chloride ions show no absorbance at this wavelength, a bromide concentration >1500 μg L⁻¹ severely interferes with nitrate determination at the trace level. On the contrary, at nitrate concentrations of >500 μg L⁻¹, this bromide interference becomes negligible. Consequently, to overcome the impact of bromide on the trace level determination of nitrate, all samples are spiked with a definite volume of a nitrate standard solution to obtain an overall nitrate concentration of >500 μg L⁻¹ which allows the exact and reliable determination of nitrate concentrations down to 25 μg L⁻¹. We will report the successful application of the method to samples of high salinity.     

Synthesis of high oil‐absorption resins of poly(methyl methacrylate‐butyl methacrylate) by suspended emulsion polymerization

The synthesis of high oil‐absorption resins by suspended emulsion polymerization process for the first time with butyl methacrylate (BMA) and short‐chain methyl methacrylate (MMA) as the monomers was studied. And the effects of different polymerization technological parameters, such as the comonomer, initiator, crosslinker, emulsifier, dispersant agent, and the agitation rate, on the oil absorbency of high oil‐absorption resins were discussed in detail. The optimum polymerization conditions were obtained. With the increasing contents of these factors, the oil absorbency increased first, and then decreased. The highest oil absorbency to toluene was 17.6 g/g. The particle morphology of the high oil‐absorption resins was observed by scanning electron microscopy (SEM). The resins were determined by FTIR spectrometry. Compared with the high oil‐absorption resins prepared by suspension polymerization process and emulsion polymerization process, the high oil‐absorption resins prepared by suspended emulsion polymerization process had the higher oil absorbency, faster oil‐adsorbing rate, better oil‐retention, and regeneration property. Copyright © 2010 John Wiley & Sons, Ltd.     

柴油溶剂中脂肪酶催化高酸值废油脂酯化制备生物柴油

采用0＃柴油作为反应溶剂,利用固定化脂肪酶催化高酸值废油脂与甲醇酯化反应制备生物柴油。来源于Candida antarctica的固定化脂肪酶Novozym435在0＃柴油溶剂中具有极高的催化活性。以酸价高达157×10-3的废油脂为原料,废油脂质量比10%的Novozym435,甲醇与废油脂初始摩尔比2∶1,0＃柴油与废油脂质量比5∶1,摇床摇速170r/min,50℃下反应2h甲酯化率可达95.10%。0＃柴油作为反应溶剂有效地溶解了高酸值废油脂和甲醇,降低了反应体系的黏度和消除了甲醇对Novozym435的负面影响,提高了Novozym435的稳定性。同时,0＃柴油溶剂对未脱胶废油脂中残留的对脂肪酶有害的磷脂等胶类物质具有一定的稀释作用。该工艺省却了溶剂蒸馏的繁琐工序,直接得到脂肪酸甲酯和石化柴油的混合燃料。     

新型液体介质二苄基甲苯的研制

二苄基甲苯具有沸点高、凝固点低、无毒、热稳定性和绝缘性好等特点,可用作热交换剂、绝缘油、塑料添加剂和光电导体材料等,是一种很有前途的新型液体介质。早在本世纪四、五十年代就有其合成方法报导。本文以甲苯和氯化苄为原料,用自制的AC—80络合物为催化剂研制了二苄基甲苯,用它作高温化学反应溶剂、电容器浸渍剂和塑料增塑剂已取得良好结果。     

巯基棉分离富集-ICP-AES测定高盐体系中痕量的铅、镉

采用巯基棉富集分离,电感耦合等离子体原子发射光谱法（ICP-AES）测定了高盐水样中痕量的铅、镉。研究表明,pH值为7时,巯基棉同时富集铅、镉的效果最好,可成功分离基体元素,以盐酸（1.5mol/L）溶液洗脱,铅、镉的加标回收率在95.0%~105.0%,相对标准偏差RSD为3.8%~9.7%。