变黏酸的基本原理及发展概况

阐述了目前油田现场使用过的三种变黏酸(聚合物温控变黏酸、聚合物pH值控制变黏酸、黏弹性表面活性剂pH值控制变黏酸)的基本原理及发展概况。并通过分析三种变黏酸存在的缺陷,提出了变黏酸今后的研究方向。     

变黏分流酸流变性影响因素的研究

利用室内合成的甜菜碱型两性表面活性剂(VES-TCJ)制备变黏分流酸。首先测定酸液中VES-TCJ浓度对鲜酸表观黏度的影响。然后模拟酸-岩反应,考察pH、VES-TCJ浓度、剪切速率、温度等因素对变黏分流酸体系变黏特性的影响。实验结果表明,当剪切速率为170 s-1,25℃下鲜酸的表观黏度小于25 mPa.s,具有良好的泵入能力。酸液表观黏度在酸-岩反应过程中不断增大,pH值为3左右时,乏酸的表观黏度最大。表面活性剂是酸液变黏的关键,VES-TCJ浓度大于4%后,变黏分流酸具有较高的表观黏度。变黏分流酸表观黏度随剪切速率的增大和温度的升高而明显减小。     

新型非离子黏弹性表面活性剂自转向酸体系研究

研制了一种新型非离子黏弹性表面活性剂变黏酸(SDA-SL)体系。浓度为5%的变黏酸体系初始黏度在20mPa.s左右,在酸液浓度为21%~10%区间出现黏度变化。其变黏特性与盐离子存在无关而仅受酸度影响。配套使用的WWD-2缓蚀剂在5%表面活性剂变黏酸体系中腐蚀速率可达SY/T5405二级标准,缓蚀剂的加入对变黏酸体系的黏度没有明显影响。     

新型温控变黏酸的合成及配方研究

选取丙烯酰胺(AM)为主要单体,2-甲基-2-丙烯酰胺基丙磺酸(AMPS)和丙烯酰氧乙基三甲氯化铵(DAC)为功能改善单体,(NH4)2S2O8-NaHSO3为引发剂,通过水溶液聚合得到温控变黏酸稠化剂PAAD。并以该稠化剂为基础设计一种温控变黏酸配方:4%PADD+1%复合交联剂m(甲醛)∶m(硫酸铝)=1∶1),并通过分析该配方的交联和破胶性能得出90℃至120℃为其最佳使用温度。     

新型温控变黏酸的合成与性能研究

以丙烯酰胺、2-丙烯酰胺-2-甲基丙磺酸和甲基丙烯酰氧乙基三甲基氯化铵为共聚单体,引入各种功能性单体,以偶氮二异丁脒盐酸盐引发合成一种新型温控变黏酸稠化剂;研究了不同交联剂用量对温控变黏酸交联效果的影响,以及丙烯酰胺与2-丙烯酰胺-2-甲基丙磺酸重量比、甲基丙烯酰氧乙基三甲基氯化铵用量、丙烯腈用量对变黏酸温控变黏过程的影响,同时评价了温控变黏酸的交联与破胶降解能力。     

川东北高温碳酸盐岩储层自转向酸研究与应用

针对川东北元坝气田高温碳酸盐岩储层水平段均匀布酸的需求,研制出一种高温转向酸产品,开展了转向酸的pH值变粘、流变等性能评价,并在现场进行了应用。研究结果表明:该转向酸具有良好的pH值变粘特性,在140℃,170 S-1条件下粘度仍然保持在100 mPa·s以上,破胶液粘度为7 mPa·s,现场酸压施工过程中在排量不变的情况下油压压差最高达到6 MPa。     

Effect of melt extrusion-solid state polycondensation circulation treatment on properties of PET

将特性黏数为0.679 dL/g的纤维级聚对苯二甲酸乙二酯(PET)切片进行5次熔融挤出-固相增黏循环处理,对固相增黏后的PET切片进行纺丝,分析了处理后的PET切片的热性能,测试了PET纤维的断裂强度及色值.结果表明:随着PET熔融挤出-固相增黏循环处理次数的增加,固相增黏后PET切片的特性黏数下降,熔点降低,纤维断裂强度和断裂伸长率下降,色值b值增加,L值减小;5次固相增黏后PET切片的特性黏数均大于0.75 dL/g,但其可纺性变差,纤维力学性能下降.     

油田酸化转向剂研究进展

盐酸酸化、酸压是碳酸盐岩油气藏主要增产措施之一，为了保证在非均质地层中酸液能够均匀推进，必须添加酸化转向剂。本文介绍了三种酸化转向剂：泡沫，聚合物以及新型的粘弹性转向剂。     

聚胺酸修饰酵母对碱性品红和亚甲基蓝的吸附行为

用面包酵母作单体、戊二醛为变联剂,制备成交联酵母后用聚胺酸进行修饰,得到聚胺酸修饰酵母.研究了pH值、染料浓度、吸附时间、温度对聚胺酸修饰酵母吸附能力的影响.结果表明,聚胺酸修饰面包酵母可同时吸附碱性品红和亚甲基蓝.在pH值为4.0～11.0,酸度对吸附量的影响较小,吸附反应分别在40、20min达到平衡,过程符合Langmuir模型,最大吸附量分别为335.9、694.2mg·g-1.     

可逆交联聚合物压裂液黏弹性及变剪切性能研究

可逆交联聚合物压裂液的携砂能力不仅与黏度有关,而且与其黏弹性相关,因此研究可逆交联聚合物压裂液的黏弹性显得十分必要。文章对可逆交联聚合物压裂液进行了应力扫描和频率扫描实验,讨论了可逆交联聚合物压裂液的黏弹性,评价了压裂液的变剪切性能。结果表明:随着聚合物浓度的增加,可逆交联聚合物压裂液线性黏弹区的范围变宽,储能模量和耗能模量增加,黏弹性提高;当温度为120~160℃,经170s-1、剪切100 min后的平均尾黏分别为56、52和40mPa·s,说明体系具有良好的耐温耐剪切性能。     

Polymeric and non-crosslinked acid self-thickening agent based on hydrophobically associating water-soluble polymer during the acid rock reaction

Different from traditional crosslinked polymer diverting agents, a polymeric and non-crosslinked acid self-thickening agent (ZPAM) based on hydrophobically associating water-soluble polymer of acrylamide (AM), [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC) and N,N′-dimethyl octadecyl allyl ammonium chloride (DOAC) was synthesized. The apparent viscosity variation of ZPAM acid solutions in acid rock reaction and rheological properties of ZPAM spent acid solutions were studied. Results showed that ZPAM acid solutions demonstrated good uninterruptedly thickening ability from low apparent viscosity to high apparent viscosity during the acid rock reaction. Meanwhile, ZPAM spent acid solutions showed good shear resistance, viscoelasticity and high temperature resistance. The thickening mechanism of ZPAM acid solutions during the acid rock reaction was explained by apparent viscosity change, rheological properties of simulative ZPAM acid solutions, and ZPAM aqueous solutions with different concentrations of CaCl₂. The results showed increasing calcium chloride concentration enhanced the hydrophobic association strength of the thickener solution, resulting in increasing solution viscosity, in other words, the self-thickening agent showed excellent salt resistance and acid resistance. In addition, the change of association strength of ZPAM acid solutions during the acid rock reaction was further confirmed via environmental scanning electron micrographs and UV spectrum. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47907.     

振动技术在注射成型中的应用

介绍了振动技术在注射成型中扩应用及其特点,讨论了聚合物熔体粘度随振动频率变化的规律,表明通过控制振动条件可以控制聚合物的冷却速度,进而控制制品的最终凝聚态结构与性能。按振动装置所处的部位不同,分三类简要介绍了振动模塑装置,展望了振动技术的应用前景。     

Synthesis and characterization of a novel biodegradable polymer poly(lactic acid–glycolic acid‐4‐hydroxyproline)

The effect of certain preparative variables, such as the composition of the feeds, the reaction time, catalyst concentration, degrees Centigrade (°C), and the reaction temperature on the properties of prepared polymer poly(lactic acid–glycolic acid‐4‐hydroxyproline) (PLGA‐Hpr), was investigated via direct melt polymerization with stannous chloride as a catalyst activated by a proton acid. The new polymer had pendant amine functional groups along the polymer backbone chain. The results with regard to the inherent viscosity and yield of PLGA‐Hpr are discussed in relation to a recently proposed polymerization mechanism. The content of lactic acid, glycolic acid, and 4‐hydroxyproline (Hpr) in the copolymer was found to affect the surface and bulk hydrophilicity of various PLGA‐Hpr copolymers. The inherent viscosity of the copolymer and the yield of the reaction depended on the reaction temperature and varied with the reaction time. The higher the 4‐hydroxyproline content of the feedzaq, the lower the inherent viscosity of the copolymer and the yield of the reaction. When the glycolic acid content was more than 70% or the content of HPr was more than 10%, the polymer changed from hemicrystalline to amorphous. The in vitro degradation rate of the PLGA‐HPr copolymers is dependent on the feed ratios of lactic acid and glycolic acid in the polymer chain. Lactic acid‐rich polymers are more hydrophobic; subsequently they degrade more slowly. The structure of this polymer was verified by infrared (IR) spectroscopy, proton nuclear magnetic resonance (¹H‐NMR) spectroscopy, X‐ray diffractometry (XRD), and differential scanning calorimetry (DSC). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3585–3590, 2007     

聚酰胺酸纺丝溶液的流变性能研究

由均苯四酸二酐(PMDA)和4,4'-二氨基二苯醚(ODA)在N,N-二甲基乙酰胺(DMAc)中共聚合制得聚酰亚胺前驱体——聚酰胺酸的纺丝溶液,采用哈克流变仪研究了溶液的流变性能。结果表明:聚酰胺酸溶液属于切力变稀的非牛顿流体;溶液的表观黏度随溶液温度的升高而降低,随溶液浓度的升高或聚合物特性黏度的增大而增大。溶液温度的升高、浓度的降低或聚合物特性黏度的减小均使得聚酰胺酸溶液呈现切力变稀行为的临界剪切速率变大,使得溶液的非牛顿指数增大,同时使得溶液的结构黏度指数减小。溶液的黏流活化能随剪切速率的增加或随溶液浓度的增高而下降。     

污水配制聚合物溶液影响因素及增粘效果分析

针对大庆油田污水配制聚合物溶液存在严重粘度损失的问题,研究了污水中阴阳离子对聚合物溶液粘度的影响并提出改善措施。研究表明:对聚合物溶液粘度影响较大的是阳离子,其顺序是:Fe~(2+)Fe3~+Mg~(2+)(Ca~(2+))Na~+(K~+)。配置要求是Na~+、K~+含量3 000 mg·L-1,最好控制在1 000 mg·L-1以下;Ca~(2+)的含量200 mg·L-1,Mg~(2+)含量100 mg·L-1。Fe~(2+)、Fe~(3+)的影响严重,需严格控制含量;而阴离子对聚合物溶液粘度的影响可以忽略不计;该镁离子为该区块影响聚合物溶液粘度的主要因素。利用腐植酸钠吸附法去除溶液中的钙镁离子,经离子吸附处理后溶液增粘14.2 m Pa·s。腐殖酸钠混合液用量为8.0 m L时对钙离子的吸附率达到77.50%,腐植酸钠混合液用量为6.0 m L时对镁离子的吸附率达到83.60%,说明可以用腐殖酸钠对钙、镁离子进行处理,且增粘效果良好。     

A Novel Cinnamic Acid‐Based Organogel: Effect of Oil Type on Physical Characteristics and Crystallization Kinetics

Oil sources (canola, sunflower, and flax‐seed oil) characterized by unsaturated fatty acids are gelled by using cinnamic acid. The physical characteristics and crystallization kinetics of cinnamic acid‐based organogels are investigated. A phase diagram with cinnamic acid concentrations ranging from 1% to 7% (w/w) shows that both canola and sunflower oil organogels are formed at 3.0% (w/w) cinnamic acid at 5 °C. The flax‐seed oil organogels are formed at 4.0% (w/w) at 5 °C. Firmness is shown to be dependent on the fatty acid composition and viscosity of the oil. Flax‐seed oil with a higher degree of unsaturation and lower viscosity tends to produce harder organogels. This result is consistent with the observations of polarized light microscopy. The organogels have low solid fat content at 35 °C which is close to the human body temperature, and no effect of oil type is found. The X‐ray diffraction measurements show β'‐form crystal exists in three types of organogels. The thermal properties vary in different types of organogels. The crystallization kinetics results suggest that three types of organogels crystallize by 1D and 2D mixed growth and instantaneous nucleation. Practical Applications: These findings provide in‐depth characteristics of cinnamic acid‐based organogels, which are a substitute for solid fats.     

Comparison of UF synthesis by alkaline‐acid and strongly acid processes

This work discusses two processes for producing urea‐formaldehyde (UF) resins. One is the alkaline‐acid process, which has three steps: usually an alkaline methylolation followed by an acid condensation and finally the addition of a final amount of urea. The other process, the strongly acid process, consists of four steps, in which the first step involves a strongly acid condensation followed by an alkaline methylolation, a second condensation under a moderately acid pH and finally, methylolation and neutralization under a slight alkaline pH. Two resins were produced using the two above described processes. The molecular weight distribution (MWD) of the resins was monitored off‐line by GPC/SEC and the final resins were characterized by GPC/SEC and HPLC. These studies showed that the two resins differ greatly in chemical structure, composition, viscosity, and reactivity. The monitoring of MWD indicated that the first condensation under a strongly acid environment leads to the production of a polymer with a distinctly different chemical structure, therefore increasing the flexibility of polymer synthesis and opening the way to the improvement of end‐use properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The influence of the ionic concentration, concentration of the polymer, degree of neutralization and chain extension on aqueous polyurethane dispersions prepared by the acetone process

There are many variables in the preparation of aqueous polyurethane (PU) dispersions. Chemical and compositional variables such as carboxylic acid concentration, concentration of the polymer, degree of pre/post-neutralization of the carboxylic acids and chain extension that all impact solution properties such as particle size and viscosity. Another variable is the method by which the dispersion is prepared; two primary methods are currently employed in industrial manufacture, the prepolymer mixing process and the acetone process. This study evaluates the impact of the chemical variables on a given PU dispersion formulation prepared by the acetone process. Changes in carboxylic acid concentration, degree of pre/post-neutralization and chain extension were found to have the expected impacts on dispersion solution properties. Increased ionic concentration, and degree of pre-neutralization led to lower particle size and higher viscosity, increased degree of chain extension led to larger particle size and lower viscosity, increased post-neutralization increased both particle size and viscosity, and increased concentration of the polymer led to a viscosity increase without any change in particle size.     

A specific effect of alkali-metal iodides and thiocyanates on the viscosity of solutions of poly(methacrylic acid) in methanol

The solution properties of poly(methacrylic acid) (PMA) in methanol are specifically affected by thiocyanates and iodides of alkali metals. The relative decrease in the reduced specific viscosity of PMA in dilute methanolic solutions due to KSCN depends only on the ratio of concentrations of polymer and salt, and is independent of temperature and polymer molecular weight. With copolymers of methacrylic acid and 2-hydroxyethyl methacrylate, the effect is weaker.     

Morphology of poly(isoprene-co-styrene-co-methacrylic acid) latex prepared by two-stage seeded emulsion polymerization

Heterogeneous latexes were prepared by a two-stage seeded emulsion polymerization process at 80°C using potassium persulfate as the initiator and sodium dodecyl sulfate as the emulsifier. Poly(styrene-co-methacrylic acid) latexes containing varying amounts of methacrylic acid (MAA) were used as seeds. The second-stage polymer was poly(isoprene-co-styrene-co-methacrylic acid). By using different methods for the addition of the MAA and by varying the amount of MAA, the hydrophilicity of the polymer phases could be controlled. The morphologies and size distributions of the latex particles were examined by transmission electron microscopy. The latexes were in all cases unimodal, and had narrow particle size distributions. The particles displayed different morphologies depending on the polymerization conditions and monomer composition. The hydrophilic properties of the two phases in combination with the internal particle viscosity and crosslinking of the second phase during polymerization were found to be the major factors influencing the particle morphology. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1543–1555, 1997