用深部处理剂JY-8提高注聚区残余聚合物的利用率

针对目前各油田聚合物驱转为水驱后,一般出现含水上升快,产油量大幅度下降的情况,以及油层内残余的大量聚合物未得到利用,而目前开发的残余聚合物再利用技术存在一些缺点,未得到推广应用,研制出新型复合处理剂JY-8。新型复合处理剂JY-8可与聚合物形成强度较高的凝胶体,将地层内残余聚合物有效地固定和絮凝,是很好的固定剂和絮凝剂,实现了“二剂合一”,达到对地层进行深部调剖、驱油的目的;同时,通过调整复合处理剂JY-8的加量等可调节成胶时间和凝胶强度。室内评价和现场应用表明,与以前的技术相比,复合处理剂JY-8可使油层内的残余聚合物利用率从原来的8％提高到15.65％,使聚合物驱后续水驱的采收率增加值从原来的10.33％提高到18.1％,在油井上起到了很好的增油、控水效果。     

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。     

电解质对聚合物分子尺寸、结构形态和渗流特性影响研究

利用动态光散射（DLS）、扫描电镜（SEM）、表观黏度和岩心流动实验等方法,研究了电解质对聚合物分子线团尺寸、结构形态和渗流特性的影响。结果表明,随电解质浓度增大,聚合物分子线团尺寸呈现“减小、增大和再减小”变化趋势。在Ca2+、Mg2+和Na+三种离子中,Ca2+和Mg2+离子对聚合物分子双电层压缩作用更强,因而对聚合物溶液黏度和线团尺寸及其分布影响更大。随着溶剂水电解质浓度的增加,聚合物分子结构形态逐渐由多层次立体无规网状向树枝状和支状转化。在聚合物驱后的后续水驱过程中,注入压力大小受滞留聚合物采出量和仍滞留聚合物分子线团膨胀两因素的影响。聚合物相对分子质量愈大,电解质对聚合物分子线团压缩或和膨胀作用愈强,后续水驱过程中压力升高幅度愈大。聚合物驱和后续水驱所用水的电解质浓度差异愈大,后续水驱阶段压力升高幅度愈大。因此在油田聚合物驱油方案设计时,建议适当增加聚合物驱和后续水驱所用水的电解质浓度差异,这对改善聚合物驱增油效果十分有利。     

黏弹性聚合物溶液在突扩孔道内的流动特性

采用上随体Maxwell本构方程,描述油藏条件下以第一法向应力差为主要特征的聚合物溶液的流变性.利用有限体积法对黏弹性聚合物溶液在突扩孔道内的流动特征进行数值模拟.绘制了流函数和速度的等值线图.研究了黏弹性的变化对微观波及效率的影响.数值模拟结果表明,聚合物溶液的黏弹性是影响波及效率的主要因素.凹角处的流动区域随着弹性的增加在不断增大,因此滞留区域不断减小,微观波及效率不断增大.具有黏弹特性的聚合物溶液相比于纯黏性的牛顿流体更利于提高驱油效率.这一结论有助于驱油工业上聚合物溶液的设计和优选.     

剪切作用对功能聚合物微观结构性能的影响研究

梳型聚合物和活性聚合物是目前常用驱油聚合物,其增黏性和黏弹性是评价其驱油能力的重要指标.为考察剪切作用对两种聚合物溶液性能的影响,分别研究了梳型聚合物和活性聚合物溶液经过模拟炮眼剪切前后的宏观和微观性能变化.结果表明,在高速剪切、拉伸应力作用下,梳型聚合物黏度损失率为40.73%,活性聚合物黏度损失率为70.10%;当剪切频率为0.02 Hz时,梳型聚合物界面扩张弹性降低了19.03%,而活性聚合物界面扩张弹性降低了68.03%;相比活性聚合物,梳型聚合物紧密的空间网状结构虽被部分破坏,但仍有疏松的网络结构,且以聚集体的形式紧密地分散在溶液中,通过DLS及AFM测定表明其粒径尺寸稍有变小;可见梳型聚合物抗剪切能力较活性聚合物强.     

含胍基抗菌聚合物的合成及应用

开发能与细菌非特异性结合的新型抗菌剂是解决细菌感染难题的方法之一。本文首先介绍了一种具有持久广谱高效抗菌性、无真核细胞毒性和细菌很难产生耐药性的含胍基抗菌聚合物;接着详细介绍了含胍基抗菌聚合物与细菌非特异性静电结合的抗菌机理;然后重点评述了主链含胍基抗菌聚合物、侧链含胍基抗菌聚合物以及表面接枝含胍基抗菌聚合物的设计理念、合成方法和抗菌性能;最后对新型含胍基抗菌聚合物的可控合成策略及应用前景进行了展望。     

聚(丙烯酰胺-丙烯酸)/聚(丙烯酰胺-二甲基二烯丙基氯化铵)分子复合型聚合物驱油剂的增粘作用

通过Brookfield粘度测定及室内岩心驱油试验评定,研究了聚(丙烯酰胺－丙烯酸)/聚(丙烯酸胺－二甲基二烯丙基氯化铵)[P(AM－AA)/P(AM－DMDAAC)]分子复合型聚合物驱油剂的增粘、抗温、抗盐性及其驱油效果.结果表明：聚合物组成一定时,其复合比影响溶液复合增粘效果;复合型聚合物溶液的抗盐性明显优于P(AM－AA)溶液的抗盐性;多价金属离子的加入是提高溶液抗盐性的有效途径.该驱油剂的最终采收率达61.91％.     

高温高矿化度条件下驱油剂中聚合物分子结构形态及其在中低渗油层中的渗流特性

利用动态光散射(DLS)、电镜扫描(SEM)和岩心驱替实验等方法, 对高温高矿化度条件下聚合物溶液和“聚合 物/表面活性剂”二元复合驱油体系中聚合物分子线团尺寸及其影响因素和在中低渗油藏环境下的渗流特性进行了实验研究, 并对其渗流规律进行了机理分析. 结果表明, 在高温高矿化度条件下, 随聚合物浓度增加, 聚合物溶液和“聚合物/表面活性剂”二元复合驱油体系中聚合物分子线团尺寸D_h都呈现“先增大后减小”的变化规律. 非离子型表面活性剂以胶束聚集体形式吸附在聚合物分子链上, 造成二元复合驱油体系中聚合物分子线团尺寸D_h大于聚合物溶液. 在溶剂水矿化度较高和岩心渗透率较低条件下, 后续注入水的冲刷和稀释作用造成岩心内滞留聚合物浓度降低, 聚合物分子线团尺寸D_h增加, 最终导致聚合物溶液和“聚合物/表面活性剂”复合体系的残余阻力系数大于阻力系数.     

阳离子抗菌聚合物

阳离子抗菌聚合物, 作为一种新型抗菌材料, 具有独特的抗菌机理和高效的抗菌活性, 并且能有效解决细菌耐药性问题, 引起了人们的广泛关注。阳离子抗菌聚合物具有有效的抗菌活性, 其抗菌活性受到亲疏水平衡、分子质量、烷基链长度和阴离子等因素的影响。抗菌活性是评价抗菌剂优劣的重要因素之一, 了解和掌握影响抗菌活性的因素, 对于优化或开发更安全、更高效的阳离子抗菌聚合物具有重大意义。本文总结了通过不同作用方式作用于细菌的多种抗菌策略, 依据影响阳离子抗菌聚合物抗菌活性的因素, 总结包括天然阳离子抗菌聚合物、季铵盐类聚合物、N-卤代胺类聚合物、膦盐和锍盐类聚合物、胍盐类聚合物和抗菌水凝胶的研究进展。最后, 对阳离子抗菌聚合物面临的挑战和未来发展方向进行了讨论。     

含钐金属有机聚合物的合成及其荧光性质研究

以合成的含双键的烷氧钐单体，与甲基丙烯酸甲酯，苯乙烯等共聚，所得聚合物用红外光谱进行了表征，用高效液相色谱测定它们的分子量及其分布、着重比较研究了这些聚合物的荧光性质。     

含芳香基团的梳状聚合物型降凝剂与沥青质协同改善合成蜡油的流变性

采用流变学实验、 差示扫描量热(DSC)分析、 显微观察及沥青质沉淀实验研究了聚丙烯酸十八酯-马来酸酐(POM)、 聚丙烯酸十八酯-马来酸酐-苯胺(POMA)及聚丙烯酸十八酯-马来酸酐-萘胺(POMN)梳状聚合物对合成蜡油的流变性能的影响规律. 实验结果表明, 这3种梳状聚合物降凝剂均能在一定程度上改善不含沥青质合成蜡油(MO-1)的低温流变性, 其中POM对MO-1蜡油的流变性改善效果最佳. 添加500 mg/kg POM后, MO-1的凝点从29 ℃降至23 ℃, 屈服值从627.20 Pa降至83.35 Pa. 而POM, POMA和POMN可以显著改善含0.3%(质量分数)沥青质的合成蜡油(MO-2)的低温流变性, 且添加500 mg/kg POMA后MO-2蜡油的流变改善效果最佳: 凝点降至3 ℃, 屈服值降至1.27 Pa. 可见, 本文制备的梳状聚合物降凝剂均能与沥青质协同改善MO-2蜡油的流变性, 并且向POM中引入芳香基团能进一步促进沥青质与降凝剂分子的相互作用, 进而增强梳状聚合物降凝剂与沥青质的协同作用.     

Preparation of hydrophobically-modified acrylamide copolymers using poly(ethylene imine) as a photoinitiator and its performance evaluation in Bohai oilfield

This paper presents copolymers of acrylamide, N,N-dimethyl-N-vinylnonadecan-1-ammonium chloride and N-(2,4-dimethylpentan-2-yl) acrylamide synthesized by photopolymerization using modified poly(ethylene imine) as initiator in water. These hydrophobically modified acrylamide copolymers were dissolved in the brine that was used in enhanced oil recovery in Bohai oilfield. It was found that when the content of N-(2,4-dimethylpentan-2-yl) acrylamide and N,N-dimethyl-N-vinylnonadecan-1-ammonium chloride were 0.1 mol % and 0.3 mol %, respectively, the resulting polymer could meet the demand of solution time and the polymer mechanical shear stability required in Bohai oilfield. The solution properties of synthesized copolymers were compared with the hydrophobically modified polymer currently used in enhanced oil recovery in Bohai oilfield.     

An experimental investigation of polyacrylamide and sulfonated polyacrylamides based gels crosslinked with cr(III)-acetate for water shutoff in fractured oil reservoirs

Abstract

Water injection as one of the most efficient and worldwide extensively employed approach in homogenous oil reservoirs suffers from early water breakthrough time as well as low oil sweep efficiency values in fractured oil reservoirs. This study investigates the potential application of Cr(III)-acetate based gel polymer system in a typical water injection process using one fractured micromodel. For this purpose, three sulfonated polyacrylamides, different in solfunation degree, and one hydrolyzed polyacrylamide were studied regarding gelation time, gel strength and stability to find the optimized conditions in terms of polymer type and concentration, and polymer/Cr(III)-acetate ratio, which were subsequently used for one dynamic test. Results illustrated the optimized conditions as AN 105 polymer with concentration of 5000?ppm and polymer/Cr(III) ratio of 5. Moreover, results showed that implementing such gel system yields an increased oil recovery value of 24.46% OOIP at 1.55 PV and delays the breakthrough time from 0.47 PV to 0.51 PV.     

Similarities and Differences of Low Salinity Polymer and Low Salinity LPS (Linked Polymer Solutions) for Enhanced Oil Recovery

Linked polymer solution (LPS) is nano-size particles made of hydrolyzed polyacrylamide (HPAM) cross-linked with aluminum citrate. The propagation of LPS has been compared to non-cross-linked polymers at low brine salinity condition. The possible differences in properties and potentials for oil recovery have been investigated using water-wet and intermediate-wet cores. The target oil for polymer flooding (PF) is assumed to be the portion of the reservoir that has been bypassed by water during waterflooding and not the residual oil saturation in flooded zones. Our recent studies have shown that a positive synergy can be obtained by combining low salinity and PF. It has been claimed in the literature that cross-linking polymer such as colloidal dispersion gels (colloidal dispersion gels (CDG), micron-size aggregates) or LPS (nano-size particles) would extend the application of polymers to also include change in residual oil saturation. The results of this study indicated higher pressure buildup when low salinity LPS was propagated through brine saturated cores compared to low salinity polymer solution. The pressure buildup was even stronger for high salinity LPS injection. In two phase flow experiments, both polymer and LPS under low salinity condition, showed approximately similar propagation and oil recovery potential when injected into water-wet and intermediate-wet cores.     

油田采出液中微量羧酸盐表面活性剂分析方法研究

油田采出液中化学剂浓度的检测是三元复合驱动态评价的重要指标之一。本文针对现场提出的对微量羧酸盐表面活性剂的检测问题,建立了一种用紫外分光光度法测定微量羧酸盐表面活性剂分析的新方法。该法简便、准确快速,线性范围宽,回收率在94.4-103.1%之间,相对标准偏差为1.38%。并根据油田生产的实际情况,探论了碱、聚合物、原油等干扰因素对测定的影响,结果满意。     

Formation and rupture mechanisms of visco-elastic interfacial films in polymer-stabilized emulsions

Considering the need for low oil price, polymer flooding has been demonstrated to be vitally important for enhanced oil recovery (EOR) in the oil industry. However, polymer-stabilized emulsions form during the displacement process, causing severe challenges in oilfield surface production, including separation performance, high operation and maintenance costs, pollution of facilities, and human health and environmental threats. In this paper, the formation and rupture of visco-elastic interfacial films are described. The emulsification structure of the polymer-stabilized emulsions is emphasized, and the film thickness is both measured and calculated. Furthermore, the thinning behavior of the interfacial films is presented based on the established destabilization process with a pulsed electric field. The emulsion stability theory is in good agreement with experimental results. The concentration of back-produced polymer is responsible for the increase in the elastic modulus of the interfacial films and dominates the formation and stability of the interfacial films. The rupture mechanism of the films and their ability to overcome droplet coalescence primarily depends on the thinning characteristics of the films in polymer-stabilized emulsions. By understanding the destabilization process, an improved thinning rate can be achieved for visco-elastic interfacial films, and the rupturing rate of high-strength films can be promoted.     

Synthesis and performances for treating oily wastewater produced from polymer flooding of new demulsifiers based on polyoxyalkylated N,N‐dimethylethanolamine

Usually, oily wastewater produced from polymer flooding (OWPF) was treated by cationic polymer in oilfield. In this paper, six block copolymers of ethylene oxide and propylene oxide were prepared by using N,N‐dimethylethanolamine (DMEA) as the acceptor (DMEA‐mnp and DMEA‐mnpq, n:m:p:q represented the weight ratio of different blocks). Most of DMEA products could perform well for treating OWPF, especially DMEA1231. Their performances were mainly affected by temperature. The reason of increasing oil removal performance of DMEA1231 with temperature was the decrease of interfacial dilational modulus (ε) with increasing temperature. When temperature raised up to 55°C, the ε of DMEA1231 had the minimum (1.5 l mN/m). Therefore, the OiW had the minimum (90 mg/l). Because DMEA1231 had the best performance, its flocculation kinetics was studied systemically. The results showed that the optimum condition for DMEA1231 was as follows: dosage was 300 mg/l, temperature was 55°C, stirring speed was 200 rpm and stirring time was 5 min. At last, the offshore oil field test was carried out to check the DMEA1231 performance. The result showed that at the optimum condition, DMEA1231 could perform as well as the cationic polymer. The most important thing was that flocs of DMEA1231 were not viscous and floated on the surface of the water. The results obtained by this paper provide a good choice for the treatment of OWPF in offshore oilfield to avoid the formation of viscous flocs. Copyright © 2014 John Wiley & Sons, Ltd.     

超稠油供氢水热裂解改质降黏研究

通过超稠油水热裂解反应前后黏度、沥青质、硫质量分数等性质的变化，研究了超稠油进行水热裂解的主要影响因素及规律。结果表明，超稠油中含有一定量的硫是地层注蒸汽温度下进行水热裂解反应的前提。温度和时间对反应有很大影响。供氢剂中四氢萘对超稠油水热裂解影响最大。四氢萘供氢剂与硫酸镍催化剂复配使用对超稠油水热裂解有协同效应。水热裂解物理模拟实验表明,胜利单家寺油田超稠油通过供氢催化水热裂解降黏率可达70%以上。胶质、沥青质、硫质量分数降低，H/C原子比提高，超稠油得到一定程度的改善。     

Polysiloxanes polymers with hyperbranched structure and multivinyl functionality

Hyperbranched polysiloxane polymers with multivinyl functionality were designed and synthesized through a “one‐step and one‐pot” deactivation enhanced atom transfer polymerization (DE‐ATRP) approach from the copolymerization of polydimethylsiloxane (PDMS) macromonomers and divinylbenzene (DVB). Various feed ratios of siloxane‐based monomer and divinyl monomers were investigated. We showed that even at DVB concentrations as high as 80 mol % in the feed, 65% yield of hyperbranched polymer could be obtained without gelation because the DE‐ATRP suppressed the rapid formation of macronetwork structures. The molecular weight, polydispersity, macromolecular structure of hyperbranched poly(DVB‐co‐PDMS) as well as its viscosity in silicone oil were characterized by GPC‐MALLS, ¹H NMR and rheometer. By tracking the relationship between the radius of gyration, elution volume and molecular weight from MALLS analysis, solid evidences of the highly branched and condensed structure of the polymers were obtained. Furthermore, the oil thickening experiments demonstrate that this hyperbranched polymer can act as a well‐controlled viscosity‐modifier for Silicone oils, which potentially will have important application in coating, cosmetic and pharmaceutical products. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Studies on Novel Polymer Materials Prepared through Intermacromolecular Complexation

The basic feature of polymers is their multi-order structure. Structure change at each level offers a possibility tomodify polymer properties and to develop new polymer materials. Therefore,novel polymer materials can be developed by tailoring their chain structure through chemical bonding among atoms, i.e., via the traditional molecular chemistry methods, e.g., polymerization of new monomer, controlling chain length (molecular weight and molecular weight distribution) and stereoregularity, copolymerization of different kinds of monomers, controlling sequence distribution,block of graft length of copolymer, etc., which have been the focus of polymer chemistry for several decades, as well as by tailoring specific supramolecular architecture using molecules as building block through intermolecular interactions, i.e., via supramolecular science methods, e.g., molecular self-assembly, intermacromolecular complexation, etc., which is a modern and fast-developing academic research field.This paper reports novel polymer materials prepared through intermacromolecular complexation,e.g., a new polymer solid electrolyte poly(metyl methacrylate-methacrylic acid)[P(MMA-MAA)]/poly(ethylene oxide) (PEO)/A2-LiClO4 developed by intermacromolecular complexation through hydrogen bonding, which has enhanced ambient ionic conductivity and fairly good mechanical and film-forming properties, a new polymer microcomposite poly(acrylonitrile-acrylamide-acrylic acid) [P(AN-AM-AA)]/poly(vinyl alcohol) (PVA) reinforced by the twin molecular chain microfibrils formed through intermacromolecular complexation of P(AN-AM-AA) with PVA through hydrogen bonding, which exhibits much better mechanical properties than its constituents and could be used to manufacture PVA based complexed fibers with higher modulus and better dyeability, a new polymer flooding agent poly(acrylamide-acrylic acid)[P(AM-AA)]/poly(acrylamide- dimethyldiallylammonium chloride) [P(AM-DMDAAC)] developed by intermacromolecular complexation of the oppositely charged polyions through Coulomb forces,which shows much higher viscosity and better resistance to temperature, shear rate and salt than its constituents, and has potential application in enhanced oil recovery.