耐温抗盐缔合聚合物的制备及性能评价

在丙烯酰胺、丙烯酸的基础上引入抗盐、耐温性能的N-芳基丙烯酰胺(N-AAM)和增粘、增溶性能的甲基丙烯酰氧乙基二甲基烷基溴化铵(MADA),从而实现聚合物耐高温高盐性能与其溶解性、增粘性的有机统一,其结构经红外光谱(FTIR)表征证实。评价了耐温抗盐聚合物(ATSP)的增粘、耐温、高温高盐长期稳定性、驱油等性能,并通过ESEM得到了其在高矿化度下的微观形貌。结果表明,耐温抗盐聚合物增粘、耐温性能优良,在高温高盐条件下稳定性好,聚合物驱及后续水驱的采收率为9.9%。     

耐温抗盐型丙烯酰胺共聚物的研究进展

根据分子设计原理,耐温抗盐型丙烯酰胺共聚物分耐温、耐盐单体共聚物、两性共聚物、疏水缔合共聚物、多元组合共聚物和梳形聚合物。综述了丙烯酰胺共聚物的耐温、抗盐的机理,介绍了驱油用耐温、抗盐型丙烯酰胺共聚物的研究现状及发展趋势,指出了丙烯酰胺共聚物在耐温、抗盐性能方面改进的关键是引入某些特殊结构。     

驱油用耐温抗盐聚合物研究进展

本文综述了国内外水溶性耐温抗盐单体聚合物、疏水缔合聚合物、两性聚合物、梳形聚合物、溶液复合型、交联聚合物等方面的研究进展,并对以上几类水溶性聚合物的耐温抗盐机理进行了阐述和分析,指出了部分类型聚合物存在的缺陷,提出了耐温抗盐聚合物交联体系和溶液复合型在驱油用耐温抗盐聚合物方面具有极大的研究价值和应用前景。     

耐温抗盐型聚丙烯酰胺研究进展

介绍了提高聚丙烯酰胺耐温抗盐性能的主要途径,综述了国内外耐温抗盐型聚丙烯酰胺的研究进展,指出了合成耐温抗盐单体共聚物和梳形聚合物是提高聚合物耐温抗盐性的有效途径.     

高温高盐油藏驱油聚合物的合成及应用

针对常规驱油用聚丙烯酰胺在高温高盐Ⅲ类油藏条件下热稳定性差和抗剪切能力弱的问题,以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)作为主要单体,引入自制的耐水解单体(APS-3),合成一种新型耐温抗盐聚合物。研究了引发剂、pH值和引发温度对驱油用聚合物黏均分子量的影响,对合成聚合物的耐温、抗盐、热稳定及抗剪切等应用性能进行测试。结果表明:在引发剂质量分数为0.40%,pH值为7～9,温度为25℃时能够合成黏均分子量达2.0×107以上的耐温抗盐聚合物。该聚合物在80℃、矿化度10×104 mg/L的条件下,老化100 d后黏度保留率为80.04%,满足高温高盐Ⅲ类油藏聚合物驱油的需求。该产品在中原油田6个井组开展应用,综合含水降低2.10%,采收率提高2.45%。     

AMPS对驱油用聚合物材料耐温抗盐性能影响

研究了含有2-丙烯酰胺基-2-甲基丙磺酸(AMPS)及无AMPS的适用于胜利Ⅱ类油藏聚驱的聚合物材料性能。结果表明,AMPS的引入未增加聚合物的疏水性及地层吸附,却明显地提高了聚合物的耐温抗盐性能及热稳定性。含有AMPS的聚合物溶液在高浓度钙离子水溶液中具有更高的表观黏度。     

高温高盐中渗油藏聚合物驱可行性研究

通过黏度测试方法,研究了温度、剪切作用等因素对2种耐温抗盐聚合物(高分子量部分水解聚丙烯酰胺HPAM和疏水缔合聚合物SSRAP)溶液性能的影响。并利用岩心驱替实验,研究了二者的渗流特征以及驱油效率。结果表明,SSRAP在高温高矿化度条件下仍具有较好的增黏能力,表现出较好的耐温耐盐抗剪切性能。在中渗多孔介质中,SSRAP溶液形成动态可逆的物理网络结构,具有良好的注入性,同时又能够建立较高的流动阻力,达到水驱流度控制的目的。在渗透率为200×10-3μm2左右的多孔介质中,1 750 mg/L的SSRAP溶液提高采收率幅度达到20%以上。因此,利用SSRAP在高温高盐中渗油藏开展聚合物驱具有较高的可行性。     

提高三次采油用聚合物耐温抗盐性的研究进展

综述了国内外三次采油用五大类驱油耐温抗盐水溶性聚合物的研究现状,提出一种提高聚丙烯酰胺类聚合物耐温抗盐性能的的新方法：即开发一种廉价高效二价金属离子络合剂。分析了二价金属离子络合剂的作用机理,并明确了以后的研究方向。     

耐温抗盐速溶型驱油用聚丙烯酰胺的制备及性能研究

为进一步改善驱油用聚丙烯酰胺的耐温抗盐性能,提高溶解速度,以丙烯酰胺粉末为单体,以有机硅过氧化物为偶联剂,以过硫酸钾和亚硫酸钠的混合溶液为复合引发体系共聚制得耐温抗盐速溶型驱油用聚丙烯酰胺,可应用于地层温度≥80℃,矿化度≥20000 mg/L,钙镁含量≥500 mg/L的环境中,溶解时间≤5 min,表现出良好的耐温抗盐性和溶解性能。与表面活性剂有良好的配伍性,深化了驱油剂加合增效,用于二元复合驱所用的驱油剂中。     

超低水解度抗盐聚丙烯酰胺的研究与应用

聚丙烯酰胺分子链上的羧基对盐极敏感,尤其在遇到高价金属离子时易发生相分离,长期在地层中稳定性较差,致使水溶液黏度大幅度降低.聚丙烯酰胺溶液在酸、碱条件下会发生迅速的水解反应,导致分子链发生卷曲,甚至产生沉淀,丧失驱油能力.如何改进聚丙烯酰胺的结构,使其具有良好的耐温抗盐性能,是目前需要解决的技术问题.通过研究低水解度抗盐聚丙烯酰胺的水解度对热稳定性的影响,从而解决目前常规聚合物存在热稳定性差的问题.超低水解度抗盐聚丙烯酰胺研究主要是在氧化还原及偶氮复合引发体系中,采用耐水解、耐盐基团2-丙烯酰胺-2-甲基丙磺酸AMPS与精制丙烯酰胺单体AM聚合,引入可抑制酰胺基水解的基团N-乙烯基吡咯烷酮NVP来抑制聚合物分子中的酰胺基的水解,在引发温度2～4℃下进行反应合成得到三元共聚物来提高耐温耐盐性能.     

三次采油用耐温抗盐聚合物的研究进展

概述三次采油用耐温抗盐聚合物的研究进展,特别是在超高分子量聚丙烯酰胺、丙烯酰胺与耐温抗盐单体的共聚物、疏水缔合聚合物、新型结构的聚丙烯酰胺共聚物等几个热门领域上总结了较新的研究结果。     

疏水缔合型聚丙烯酰胺驱油剂的合成与性能评价

针对聚丙烯酰胺的研究现状及其应用中存在的问题,研制出一种抗温、抗盐性能较强,具有一定增粘性能的新型疏水缔合水溶性聚合物。本文通过较为简易的酸醇直接酯化法合成了一种丙烯酸正辛酯,确定了最适宜的合成条件;将该疏水单体与丙烯酰胺采用胶束共聚法合成了一种新型疏水缔合水溶性聚合物,考察了聚合物浓度、盐及温度等对疏水缔合共聚物溶液表观粘度的影响,实验结果表明,合成的聚合物具有良好的耐温抗盐性能。     

Thermal behavior and morphological properties of novel magnesium salt–polyacrylamide composite polymers

Magnesium salt–polyacrylamide composite polymers have been prepared by blending magnesium chloride and magnesium hydroxide, respectively, with polyacrylamide aqueous solution. The thermal behavior of the dried magnesium salt–polyacrylamide composite polymers has been studied. Differential scanning calorimetric (DSC) analysis and thermal gravimetric analysis (TGA) were carried out to investigate the changes of the composite polymers' behavior with temperature. The kinetics of the thermal decomposition of magnesium salt–polyacrylamide composite polymers was investigated over temperature range of 35–800°C with three heating rates of 10, 20, and 40°C/min under nitrogen atmosphere. Flynn and Wall's model was usedto determine the activation energies of thermal decomposition for magnesium salt–polyacrylamide composite polymers. The activation energies needed to decompose 50 wt% of magnesium hydroxide‐polyacrylamide (MHPAM) composite polymer ranged from of 28.993–174.307 kJ/mol which are higher than the values for magnesium chloride–polyacrylamide (MCPAM) composite polymer (21.069–39.412 kJ/mol). Therefore, MHPAM composite polymer has a better thermal stability compared with MCPAM composite polymer. The morphological properties of magnesium salt–polyacrylamide composite polymers were studied using scanning electron microscopy (SEM). Energy‐dispersive X‐ray (EDX) spectroscopy was used to determine the composition of the chemical elements. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Evaluation of hydrophobically associated polyacrylamide‐containing aqueous fluids and their potential use in petroleum recovery

Acrylamide and tridecyl acrylate copolymers were synthesized by micellar copolymerization to obtain water‐soluble, hydrophobically modified polymers. Rheological properties of the obtained polymer solutions were evaluated and compared to those of solutions of a commercial polyacrylamide currently used in the petroleum industry. The behavior of the copolymer solutions was studied as a function of the variation of hydrophobic monomer content incorporated in the copolymer as well as the salt content of the aqueous medium, for diluted and semi‐diluted regimens. Comparative studies of such effects on the intrinsic viscosity and the critical concentration of those polymers were conducted. The increase in hydrophobic monomer content produced a sudden increase in the bulk and absolute viscosity of the polymeric solutions, a trend that was more intense from a certain concentration typical for each polymer. Salt addition led to lower bulk viscosity caused by a stronger interaction among hydrophobic groups, resulting from minimized exposure of such groups and water. The same effect was observed for the critical concentration. A comparison of the synthesized polymers with industrial polyacrylamide showed that the synthesized polymers were characterized by advantageously high shear strength and high salt resistance. However, in the absence of salts, higher copolymer amounts were needed to prepare solutions whose viscosity was the same as that of commercial polyacrylamide. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3686–3692, 2004     

高性能PAM类产品的研究 Ⅰ聚合产物分子量的提高

高性能聚丙烯酰胺(PAM)类产品的制备与开发是近年来丙烯酰胺(AM)聚合领域最热门的研究课题之一,其工作多集中在如何获得高分子量聚合产品,如何使产品更加耐温、耐盐和抗剪切等方面.本专论基于理论分析和前人研究结果.分两部分介绍和探讨了实现PAM类产品高性能化的若干途径和方法:I聚合产物分子量的提高;Ⅱ耐温、耐盐、抗剪切性能的改善.本文为第一部分,着重从聚合反应规律,聚合工艺方法和聚合引发体系等方面探讨了由AM聚合反应获得高分子量PAM的合成途径及方法.     

Thermal stability of polymers based on acrylamide and 2-acrylamido-2-methylpropane sulfonic acid in different temperature and salinity conditions

Partially hydrolyzed polyacrylamide (PHPA) is the most widely used polymer in enhanced oil recovery (EOR) applications. However, under conditions of high temperature and salinity, the PHPA molecules become hydrolyzed, causing a drastic reduction of the viscosity of the polymer solution due to the presence of negative charges, making the molecules more susceptible to interactions with cations. In this sense, in order to increase the stability of these polymers, an anionic monomer more resistant to cations such as 2-acrylamido-2-methylpropane sulfonic acid (AMPS) has been incorporated into the HPAM molecules. This work evaluated the thermal stability of a copolymer (acrylamide and AMPS - AN125) and a terpolymer (acrylamide, acrylate, and AMPS-FP5115) in the time course of 360 days. The tests were carried out in typical conditions of Brazilian offshore reservoirs, such as absence of oxygen, high temperature, and high salt concentration. The test method involved measurements of intrinsic viscosity in function of time and determination of the hydrolysis degree of the polymers by elemental analysis. The copolymer AN125 was more stable under the test conditions than the terpolymer FP 5115 due to the presence of a higher concentration of AMPS in the copolymer. The AMPS group was hydrolyzed to AA at a temperature of 100 °C, however, the increase in salt concentration delayed the onset of this degradation. The tests indicated that the presence of a higher AMPS content in the copolymer does not prevent the polymer from undergoing hydrolysis, but delays the polymer precipitation step in the solution.     

三次采油用聚合物驱油剂PL-2的合成与溶液性能研究

采用胶束聚合的方法合成了三次采油用聚合物PL-2,室内研究了表面活性剂的浓度、疏水单体、阴离子单体含量以及在盐水中聚合物溶液表观粘度的影响,并进一步评价了合成聚合物的抗剪切性与热稳定性。实验结果表明:疏水单体与阴离子单体含量分别在0.6%与10%时,该聚合物驱油剂PL-2具有很好的增粘效果,且抗剪切及热稳定性能优良,其性能可以满足高温、高矿化度油藏聚合物驱油的要求。     

甲基丙烯酰胺丙基三甲基氯化铵单体、聚合物合成及应用研究进展

甲基丙烯酰胺丙基三甲基氯化铵(MAPTAC)是一种具有耐酸碱耐温优点的季铵盐阳离子单体,其聚合物具有良好的应用前景.首先,该文分别介绍了MAPTAC单体及其聚合物的合成研究进展;其次,分别概述了MAPTAC聚合物在日化用品、石油开采、水处理、医学等领域的应用研究进展.最后,在提高MAPTAC聚合物相对分子质量、缩小MAPTAC聚合物的相对分子质量分布及拓展聚合物应用领域方面进行了展望.     

Viscosity and retention of sulfonated polyacrylamide polymers at high temperature

The viscosity and retention of several copolymers of acrylamide (AM) with sodium salt of 2‐acrylamido‐2‐methylpropane sulfonic acid (PAMS), and also hydrolyzed polyacrylamide (HPAM) have been studied under aerobic condition with and without the sacrificial agent, isobutyl alcohol (IBA) added at a temperature of 80°C. Parallel experiments have been performed in synthetic seawater (SSW) and 5 wt % NaCl. The viscosity at high temperature has been studied as a function of aging time, shear rate, sulfonation degree, molecular weight, and concentration of IBA. The retention in porous medium for sulfonated polyacrylamide polymers was measured in core floods using outcrop Berea sandstone. For the studied polymer sacrificial agent may protect polymer structure at high temperature. Higher sacrificial agent concentration gives better thermal stability in both 5 wt % NaCl and SSW solvents. Sulfonation degree also has a direct effect on thermal stability, i.e., higher sulfonation degree lead to better thermal stability in terms of viscosity. By increasing temperature, less relative reduction in polymer solution viscosity was observed for the polymer with lower molecular weight. The presence of divalent ions at high temperature leads to strong reduction of HPAM polymer solution viscosity, but the viscosity is better maintained for PAMS copolymer solution at high temperature. The precipitation of HPAM first occurred after 3 months at 80°C and for PAMS copolymer with lowest sulfonation degree precipitation started after 7 months. For the studied polymers the retention was found to be relatively independent of temperature and compared to HPAM a much lower retention is observed for the sulfonated copolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thermoviscosifying polymer used for enhanced oil recovery: rheological behaviors and core flooding test

Polymer flooding represents one of the most efficient processes to enhance oil recovery, but the poor thermostability and salt tolerance of the currently used water-soluble polymers impeded their use in high temperature and salinity oil reservoirs. Thermoviscosifying polymers (TVPs) whose viscosity increases upon increasing temperature and salinity may overcome the deficiencies of most water-soluble polymers. A novel TVP was studied in comparison with traditional partially hydrolyzed polyacrylamide (HPAM) in synthetic brine regarding their rheological behaviors and core flooding experiments under simulated high temperature and salinity oil reservoir conditions (T: 85 °C, and total salinity: 32,868 mg/L, [Ca²⁺] + [Mg²⁺]: 873 mg/L). It was found that with increasing temperature, both apparent viscosity and elastic modulus of the TVP polymer solution increase, while those of the HPAM solutions decrease. Such a difference is attributed to their microstructures formed in aqueous solution, which were observed by cryogenic transmission electron microscopy. Core flow tests at equal conditions showed an oil recovery factor of 13.5 % for the TVP solution versus only 2.1 % for the HPAM solution.