表面改性SiO_2对PP基复合材料性能的影响

分别采用正辛基三乙氧基硅烷、正十二烷基三甲氧基硅烷对纳米SiO2晶须表面接枝改性,并制备了改性PP/nano-SiO2复合材料,探讨了偶联剂种类与复合材料性能间的关系。研究发现:改性PP/nano-SiO2复合材料弯曲强度、拉伸强度和弯曲模量略低于未改性的PP/nano-SiO2复合材料,但冲击强度和断裂标称应变更优;改性PP/nano-SiO2复合材料具有更好的耐磨性能和耐刮擦性能;正十二烷基三甲氧基硅烷改性纳米SiO2能够明显提高复合材料的热变形温度,且耐刮擦性能和耐磨性能优于正辛基三乙氧基硅烷改性纳米SiO2和未改性SiO2,能够在车用内饰件领域得到更好的应用。     

硅烷防护材料的分子动力学模拟及试验

通过分子动力学模拟三种硅烷材料在水泥毛细孔隙中的传输过程,并通过毛细吸水试验、接触角测定进行试验验证.模拟发现,硅烷羟基部分通过离子键与C-S-H界面连接,烷基部分指向孔道中心,降低界面亲水性.同时硅烷分子之间会形成团簇体,抑制通道中水分子传输.试验结果与模拟结果基本吻合.接触角测试表明,涂覆硅烷材料后,水泥试块的接触角增大,其中涂覆辛基三乙氧基硅烷的试块接触角达到130°左右.毛细吸水试验结果表明,涂覆辛基三乙氧基硅烷的试块在48 h后的吸水量仅为165 g·m-2,比未处理的试块吸水量(789 g·m-2)降低了79％左右.甲基三乙氧基硅烷和乙烯基三乙氧基硅烷也具有一定的防水效果,但吸水量比涂覆辛基三乙氧基硅烷的试块稍多.     

新型纳米活性流体协同改变油湿性砂岩表面润湿性的机理

以带正电的碳酸钙纳米颗粒和阳-非离子双子表面活性剂为原料，制备了一种纳米活性流体。通过Zeta电位、红外光谱（IR）、石英晶体微天平（QCM）、接触角测量和自发渗吸实验等方法研究了制得纳米活性流体中碳酸钙纳米颗粒和阳-非离子双子表面活性剂协同改变油湿性砂岩表面润湿性的机理。结果表明，纳米活性流体处理后的油湿性砂岩表面红外光谱中，原油的羰基吸收峰强度低于阳-非离子双子表面活性剂处理后的砂岩表面羰基吸收峰强度；当阳-非离子双子表活剂质量分数均较高时（>0.003%），纳米活性流体中的碳酸钙颗粒促进了双子表面活性剂和原油羧基离子对的形成和解吸附过程，使得纳米活性流体处理过的砂岩表面共振频率变化量（Δf）比阳-非离子双子表面活性剂处理过的砂岩表面Δf小；接触角测定结果进一步确认，纳米活性流体改变油湿性砂岩表面润湿性的效果比单一阳-非离子双子表面活性剂和碳酸钙纳米颗粒效果更好，纳米活性流体中的两种组分起到协同效应。     

阳离子表面活性剂对纳米SiO2流体稳定性的影响

通过研究纳米SiO2/水纳米流体的稳定性建立了差示透光率法,并利用差示透光率法和重力沉降法研究了阳离子表面活性剂十四烷基三甲基溴化铵(TrAB)、十六烷基三甲基溴化铵(CTAB)和十八烷基三甲基溴化铵(OTAB)对纳米SiO2流体稳定性的影响.结果表明:阳离子表面活性剂吸附在纳米SiO2颗粒表面后促使纳米流体形成凝胶,且不同阳离子表面活性剂对2.5wt％ SiO2纳米流体稳定性的影响均存在三个临界浓度C1、C2和C3,这三个临界浓度的大小与阳离子表面活性剂疏水链长密切相关,碳链越长,相应临界浓度越低,并提出了阳离子表面活性剂在纳米SiO2表面吸附后纳米颗粒之间的疏水缔合作用理论.     

一种新型纳米渗吸剂合成与压驱工艺研究

以顺丁烯二酸酐、脂肪醇聚氧乙烯醚为原料,合成一种新型纳米渗吸剂(N-SA),用红外光谱仪、核磁氢谱仪对产物进行表征,用表面张力仪测定cmc,用Zeta电位及纳米粒度分析仪和透射电镜检测粒径分布及形态,用光学接触角测量仪和旋转界面张力仪测试对岩心的润湿性能改变,使用具塞渗吸瓶和岩心流动仪对纳米渗吸剂(N-SA)的性能进行测试。结果表明,纳米渗吸剂(N-SA)的cmc为0.042 g/L,在水溶液中以球形胶束存在,0.1%的粒径为91.2 nm,与煤油的界面张力低于1×10^(-3)mN/m,可以使亲油性岩心转变为亲水性,对于低渗岩心,静态渗吸效率为45.3%,可提高动态水相相对渗透率。将纳米渗吸剂(N-SA)与压裂相结合,提出压驱工艺,并在X井取得良好效果,具有推广前景。     

聚丙烯酸酯原位乳液聚合包覆SiO2的研究

用经甲基丙烯酰氧基丙基三乙氧基硅烷（MAPS）处理过的纳米SiO2作种子，进行聚丙烯酸酯（ACR）的原位乳液聚合，制成了MAPS－SiO2/ACR复合物；探讨了种子乳液聚合的过程，分析了包覆机理，讨论了SiO2的用量对聚合反应速率及残渣率的影响，结果表明：在以纳米SiO2为种子的ACR乳液聚合中，单体的转化率及聚合反应速率随SiO2用量的增加而下降；当SiO2的用量为10％时，复合物与聚氯乙烯共混后，其拉伸强度和冲击强度最高。     

羧基改性单分散二氧化硅纳米球的制备与表征

以浓氨水为催化剂、四乙氧基硅烷(TEOS)为原料,利用Stober溶胶-凝胶法制得二氧化硅(SiO2)微球。粒度仪测试结果表明,SiO2微球粒径为30～100nm,其平均粒径随着催化剂用量的增加而增大。进一步用γ-氨丙基三乙氧基硅烷对SiO2纳米球进行表面改性,后与苯偏三酸酐反应,得到羧基改性的SiO2纳米球。利用TEM、FT-IR对羧基改性纳米球进行表征。结果表明,改性过程对SiO2纳米球的粒径无影响,羧基通过化学键结合在SiO2纳米球表面。     

乙烯基三乙氧基硅烷改性SiO2纳米粒子的研究

本文利用乙烯基三乙氧基硅烷对SiO2纳米粒子表面进行改性，考察了偶联剂的用量对粒子表面润湿性的影响，同时利用红外光谱、透射电镜对改性前后的纳米粒子进行了表征。     

乙烯基三乙氧基硅烷改性SiO2纳米粒子的研究

本文利用乙烯基三乙氧基硅烷对SiO2纳米粒子表面进行改性，考察了偶联剂的用量对粒子表面润湿性的影响，同时利用红外光谱、透射电镜对改性前后的纳米粒子进行了表征。     

高亲水性纳米二氧化硅颗粒稳定Pickering乳液

用未修饰的高亲水性纳米二氧化硅颗粒(SiO2 NPs)在其等电点附近制备Pickering乳液。结果表明,等电点(pH 2.7)条件下SiO2 NPs借助高能均质与油水界面剧烈混合,并在范德华引力的驱动下以弱吸附的状态在界面处负载,从而稳定得到O/W型Pickering乳液。增加SiO2 NPs的浓度或减小油相体积分数可提高单位油滴界面的颗粒负载率,增大连续相黏度并促进乳液液滴之间形成三维网络结构从而提高乳液稳定性。通过调节连续相的pH以促进SiO2 NPs表面的硅烷醇发生质子化与去质子化的转变,实现乳液多次pH响应循环。     

裂缝性致密油藏润湿性提高采收率技术研究

在裂缝性致密储层中,水驱效率往往由水自发吸入含原油基质块控制。当基质是原油润湿或中性润湿时,原油很难通过自发渗吸采出。研究目的是确定可以添加到注入水并提高深吸效率的表活剂组合。通过评价几种表活剂在储层温度和矿化度下的水稳定性并在富含粘土的砂岩上测量接触角,对储层岩心进行渗吸试验。结果表明使用一定浓度的表活剂溶液可实现矿物板的润湿反转。之后通过在致密油湿或中性润湿砂岩岩心上进行的自发吸入试验获得较润湿反转前68%的渗吸增量。同时数值模拟的研究也证实随着润湿性的变化,原油回收率也发生明显改变,且与断裂密度和原油粘度相关。     

Stabilizing silica nanoparticles in high saline water by using polyvinylpyrrolidone for reduction of asphaltene precipitation damage under dynamic condition

In this study, the performance of stable nanofluid containing SiO_2 nanoparticles dispersed and stabilized in high salinity brine for asphaltene inhibition in dynamic condition is evaluated. In the first stage of this work, the stability of silica nanoparticles in different range of water salinity(0–100000 mg·L~(-1)) is investigated. Next, stable nanofluid containing highest salinity is selected as asphaltene inhibitor agent to inject into the damaged core sample. The estimated values of oil recovery for base case, after damage process and after inhibition of asphaltene precipitation using nanofluid are 51.6%, 36.1% and 46.7%, respectively. The results showed the reduction in core damage after using nanofluid. In addition, the relative permeability curves are plotted for the base case, after damage process and also after inhibition of asphaltene precipitation using nanofluid. Comparison of relative permeability curves shows, relative permeability of oil phase decreased after damage process as compared with the base case. But after using nanofluid the oil relative permeability curve has shifted to the right and effective permeability of oil phase has been improved.     

纳米SiO2在有机硅涂料中的分散性研究

利用纳米SiO2粒子所具有的特殊性能,研制出新的有机硅基纳米SiO2防护涂料.纳米SiO2粒子在有机硅中的分散和稳定性问题是制备纳米SiO2有机硅涂料的关键.为了解决纳米SiO2粒子在有机硅中的分散性和稳定性,对纳米SiO2粒子进行了表面改性处理,从而改变了纳米SiO2粒子表面的理化性能,同时利用物理分散和化学分散相结合的方法进行纳米SiO2在有机硅涂料中的分散,采用适合的制造工艺制备纳米SiO2有机硅涂料.通过透射电镜(TEM)、傅立叶变换红外光谱(FTIR)等技术分析了纳米SiO2粒子在有机硅涂料中的分散性和稳定性.     

Laboratory Studies to Determine Suitable Chemicals to Improve Oil Recovery from Garzan Oil Field

Garzan oil field is located at the south east of Turkey. It is a mature oil field and the reservoir is fractured carbonate reservoir. After producing about 1% original oil in place (OOIP) reservoir pressure started to decline. Waterflooding was started in order to support reservoir pressure and also to enhance oil production in 1960. Waterflooding improved the oil recovery but after years of flooding water breakthrough at the production wells was observed. This increased the water/oil ratio at the production wells. In order to enhance oil recovery again different techniques were investigated. Chemical enhanced oil recovery (EOR) methods are gaining attention all over the world for oil recovery. Surfactant injection is an effective way for interfacial tension (IFT) reduction and wettability reversal. In this study, 31 different types of chemicals were studied to specify the effects on oil production. This paper presents solubility of surfactants in brine, IFT and contact angle measurements, imbibition tests, and lastly core flooding experiments. Most of the chemicals were incompatible with Garzan formation water, which has high divalent ion concentration. In this case, the usage of 2-propanol as co-surfactant yielded successful results for stability of the selected chemical solutions. The results of the wettability test indicated that both tested cationic and anionic surfactants altered the wettability of the carbonate rock from oil-wet to intermediate-wet. The maximum oil recovery by imbibition test was reached when core was exposed 1-ethly ionic liquid after imbibition in formation water. Also, after core flooding test, it is concluded that considerable amount of oil can be recovered from Garzan reservoir by waterflooding alone if adverse effects of natural fractures could be eliminated.     

纳米SiO2对动态硫化EPDM/PP热塑性硫化胶性能的影响

采用不同硫化体系动态硫化制备三元乙丙橡胶/聚丙烯热塑性硫化胶(EPDM/PP TPVs),并在制备的过程添加不同量的纳米SiO2。结果表明酚醛树脂2402动态硫化得到的EPDM/PP TPVs性能最佳。随着纳米SiO2添加量的增加,EPDM橡胶粒子的粒径先减小后增大,当纳米SiO2的添加量为10份时,EPDM橡胶粒子的粒径达到最小。流变性能研究表明添加纳米SiO2使EPDM/PP TPVs的加工性能变差。动态机械分析仪(DMA)研究表明纳米SiO2提高了TPVs中PP相的玻璃化转变温度。当纳米SiO2的添加量为10份,TPVs的拉伸强度达到最高为23.7MPa,提高了19.1%,断裂伸长率达到最大为431%,提高了11.1%。纳米SiO2使EPDM/PP TPVs的热稳定性和耐热老化性能变好。     

表面活性剂对特低渗油藏的适用性及应用

为评价表面活性剂WLW对特低渗油藏的适用性,研究了WLW的渗吸特性、乳化性能和界面张力及其在特低渗油藏物理模拟岩心驱油实验和现场中的应用。室内实验结果表明,WLW对注入水的渗吸效率有促进作用;注入质量分数0.2%的WLW溶液,可在水驱基础上提高驱油效率5%左右;WLW在特低渗岩心中提高驱油效率的幅度明显高于中低渗岩心。2011—2013年在长庆靖安油田A1和A2井组开展注WLW现场试验,累计增油4 781 t,WLW对于特低渗油藏提高采收率效果明显。     

平面非均质油藏水气交替驱提高采收率室内实验研究

水气交替(WAG)驱提高采收率技术和应用研究在我国处于起步阶段。借助室内驱替实验,明确了WAG驱在平面非均质油藏的适应性及其提高采收率的作用机理。将并联式填砂管替代常规岩心夹持器,进一步减弱了长岩心驱替产生的末端效应和应力敏感现象,模拟真实的平面非均质油藏条件。实验结果表明,WAG驱可减缓气窜,改善吸水剖面。注入N2可加强三相分子之间的交换、扩散、渗吸作用。对于非均质性严重的储层,水气交替注入后水驱封堵高渗带,气驱驱扫小孔隙,帮助形成稳定的驱替前缘,提高低渗储层的驱油效率。     

Superior enhancement of imbibition recovery by novel surfactant mixtures with a large hydrophobic group combined with nanosilica

Low interfacial tension (IFT) drainage and imbibition are effective methods for improving oil recovery from reservoirs that have low levels of oil or are tight (i.e., exhibit low oil permeability). It is critical to prepare a high efficient imbibition formula. In this work, a novel 2,4,6-tris(1-phenylethyl)phenoxy polyoxyethylene ether hydroxypropyl sodium sulfonate (TPHS) surfactant was synthesized and evaluated for imbibition. Its structure was confirmed by Fourier transform infrared spectroscopy and the interfacial tension (IFT) of the crude oil/0.07% TPHS solution was 0.276 mN/m. When 0.1 wt% TPHS was mixed with 0.2 wt% alpha olefin sulfonate (AOS), the IFT was lowered to 6 × 10⁻² mN/m. The synergy between nanoparticles (NPs) and TPHS/AOS mixed surfactant was studied by IFT, contact angle on sandstone substrates, zeta potential, and spreading dynamics through microscopic methods. The results show that the surfactant likely adsorbs to the NP surface and that NP addition can help the surfactant desorb crude oil from the glass surface. With the addition of 0.05 wt% SiO₂ NPs (SNPs), the imbibition oil recovery rate increased dramatically from 0.32%/h to 0.87%/h. The spontaneous imbibition recovery increased by 4.47% for original oil in place (OOIP). Compared to flooding by TPHS/AOS surfactant solutions, the oil recovery of forced imbibition in the sand-pack increased by 12.7% OOIP, and the water breakthrough time was delayed by 0.13 pore volumes (PV) when 0.05% SNPs were added. This paper paves the way for enhanced oil recovery in low-permeability sandstone reservoirs using novel TPHS/AOS surfactants and SNPs.     

纳米SiO2改性醇溶性蓖麻油-聚氨酯树脂的制备与表征

利用端氨基偶联剂KH-550对纳米SiO2进行表面改性,在超声场作用下制备疏水性纳米SiO2粒子,并将其均匀分散到蓖麻油(CO)-聚氨酯溶液,通过红外光谱(IR)、热重分析(TGA)和扫描电镜(SEM)等测试方法,探讨醇溶性聚氨酯的热稳定性、铅笔硬度和胶膜力学性能等。红外分析表明,PU大分子和纳米SiO2之间形成化学键,形成了Si—O—Si结构。当蓖麻油添加量为多元醇总质量的10%时,拉伸强度由原来的6.8 MPa增加到16.2 MPa,吸水率降低至原来的1/2。纳米SiO2颗粒掺杂量由0%增加到2%时,PU涂膜的失重速率最高点温度由原来的345℃提高至369℃,热分解温度也有所提高。涂膜热重曲线出现右移。     

聚合物微球提高低渗油藏渗吸效率微观实验研究

为了研究聚合物微球对低渗油藏渗吸采收率的作用效果,通过物理模拟实验和微观实验的方法分析了聚合物微球对剩余油的动用情况,研究了岩心自发渗吸的最佳效果。结果表明:带有聚合物微球的溶液与未加入聚合物微球的溶液相比对提高采收率起到了一定的作用,采收率在14%~15%,渗吸过程主要靠重力的作用凭借逆向渗吸的方式将原油置换出来。从微观实验可以看出聚合物微球对动用簇状剩余油有明显效果,对孔道进行了封堵,提高了渗吸液的波及体积,进而提高了采收率。