双子型VES清洁泡沫压裂液稳泡性能

针对双子型黏弹性表面活性剂(VES)泡沫压裂液不同于常规泡沫压裂液的稳泡机理,采用微观气体扩散测定、低温冷冻电镜透射、界面流变测试、微观可视化等研究手段,对排液速度、液膜强度、气体扩散速度等进行测试分析。研究结果表明:VES泡沫压裂液的液相中形成互相缠绕的蠕虫状胶束,减缓液膜排液速度,促使泡沫析液半衰期相对单一表面活性剂泡沫延长2~3个数量级;VES泡沫气液界面上吸附达到饱和状态的表面活性剂分子以及体相中互相缠绕的蠕虫状胶束抑制了气体扩散作用;VES泡沫液膜具有较高的界面扩张黏弹模量,这有助于增强气泡抵抗变形及自我修复的能力,进而提高泡沫适应压力波动的能力。这些特性使双子型VES清洁泡沫压裂液具有比常规泡沫压裂液更良好稳泡性能。     

纳米复合纤维基表面活性剂压裂液性能评价

黏弹性表面活性剂(VES)压裂液因为具有低伤害的特性,在煤层压裂中得到广泛应用。针对煤层割理裂隙发育、对表面活性剂吸附量大的特点,在阴离子表面活性剂压裂液中引入功能性纳米复合纤维,形成纳米复合纤维基表面活性剂压裂液体系。通过实验确定纤维的最佳质量分数为0.4%～0.7%,最佳长度为6～12 mm。对压裂液体系开展了室内评价,结果显示此压裂液体系在预防支撑剂回流、缓解煤粉聚集、降低滤失、增强携砂性能、降低摩阻等方面效果显著,且对支撑剂层的导流能力伤害较小。此体系对于中国煤层气开发具有一定参考价值。     

黏弹性表面活性剂压裂液的合成与性能

合成了黏弹性阳离子表面活性剂,以此为主剂配制出不同浓度的黏弹性表面活性剂(VES)压裂液体系,考察其主要性能.结果表明:VES压裂液体系具有很好的低黏度特性、耐剪切性和黏弹性.在室温下,剪切速率180,s-1,黏度均小于20,mPa.s,且不随时间变化;高速剪切(996,s-1)后体系的黏度能得到快速恢复;在应力扫描范围内,弹性模量一直大于黏性模量,属于弹性流体;破胶后黏度小于3,mPa.s,表面张力小于35,mN/m,无残渣,破胶效果好,易返排,对地层伤害小.     

添加纳米SiO_2颗粒的泡沫表面性质及调剖性能

泡沫驱在三次采油中取得了很好的开采效果,但是泡沫的稳定性制约其应用,在表面活性剂中加入纳米SiO_2以提高泡沫的稳定性。利用Tracker全自动界面流变仪测量复配体系的表面张力和界面扩张黏弹模量;利用微观驱油试验模型分析添加纳米SiO_2泡沫体系的驱油机制并与普通泡沫体系进行对比;利用岩心试验研究纳米SiO_2含量对泡沫体系驱油效果的影响。结果表明:随着纳米颗粒质量分数的增加,泡沫的稳定性和界面扩张黏弹模量均增加;泡沫稳定性的增强可以有效避免气液分离现象,使气泡更好地圈闭气体,提高泡沫的封堵效率,增加波及体积;界面扩张黏弹模量增强可以加强对孔道壁面油的挤压和携带作用;随着纳米SiO_2质量分数的增加,含油岩心的采收率及压差均上升,与普通泡沫驱比采收率可提高25%以上。     

一种新型纳米复合清洁压裂液的研究与应用

研发了一种新型表面活性剂,与助表面活性剂组成复合表面活性剂体系(VES-M)。优选了疏水缔合高分子聚合物(HMPAM)和纳米材料颗粒ZnO,形成纳米复合清洁压裂液体系,具有表面活性剂用量低、添加剂种类少的特点。室内试验表明,与常规黏弹性表面活性剂清洁压裂液相比,该体系具有更好的耐温性能及耐剪切性能,较好的降滤失性、黏弹性及携砂性;且破胶彻底、速度快,破胶后无残渣,岩心伤害率仅为9.3%。2014年在苏里格气田东二区进行现场应用,试气无阻流量均值约为其相同地质条件邻井的2.0倍,为致密气藏低伤害高效改造提供了一条有效途径。     

SiO_2纳米颗粒强化的CO_2泡沫压裂液体系

随着CO_2泡沫压裂技术的发展,传统聚合物增稠型泡沫强化剂暴露出难破胶、高残渣、伤害地层等问题。将SiO_2纳米颗粒作为CO_2泡沫压裂液的新型强化剂,系统研究强化泡沫的界面流变性、生成及稳定性、黏度、滤失及伤害性。结果表明:SiO_2纳米颗粒吸附在泡沫气液界面上增大了界面粗糙度,并提升了高温高压下界面黏弹模量,增强了泡沫液膜抵抗及恢复形变能力;虽然强化泡沫的生成能力减弱,但泡沫在高温高压下的稳定性获得显著提升,且其生成能力随压力增大而增强;泡沫质量分数为50%～93%时,0.5%的SiO_2纳米颗粒将泡沫有效黏度提高了2.2～4.8倍,同时泡沫滤失控制能力增强,气、液相滤失系数对渗透率的敏感性减弱;强化泡沫具备低伤害性。     

纳米复合纤维基表面活性剂压裂液研究

粘弹性表面活性剂(VES)压裂液因为具有低伤害的特性,在煤层压裂中得到广泛应用。针对煤层割理裂隙发育、对表面活性剂吸附量大的特点,在阴离子表面活性剂压裂液中引入功能性纳米复合纤维,形成纳米复合纤维基表面活性剂压裂液体系。通过实验确定纤维的最佳质量分数为0.4%～0.7%,最佳长度为6～12mm。对压裂液体系开展了室内评价,结果显示此压裂液体系在预防支撑剂回流、降低滤失、增强携砂性能、降低摩阻等方面效果显著,且对支撑剂层的导流能力伤害较小。此体系对于国内煤层气开发具有一定参考价值。     

纳米SiO_2改性环氧-聚三唑胶黏剂体系研究

为改善改性聚三唑胶黏剂(E-PTA)高温粘接性能和耐湿热老化性能,将纳米SiO_2引入E-PTA中制备E-PTA-SiO_2胶黏剂。研究纳米SiO_2含量对E-PTA-SiO_2粘接性能、高温性能和耐湿热老化性能的影响。利用傅里叶变换红外光谱仪(FT-IR)、激光粒度分析、电子扫描显微镜(SEM)、差示扫描量热法(DSC)、动态力学热分析(DMA)和热质量分析仪(TGA)对纳米SiO_2改性情况、在胶黏剂中的分散情况以及E-PTA-SiO_2的固化行为和热性能进行研究,同时研究了E-PTA-SiO_2对7075铝合金试样的粘接性能和耐湿热老化性能。结果表明:玻璃化转变温度T_g随着纳米SiO_2质量分数的提高先升高后降低;E-PTA-SiO_2胶黏剂与7075铝合金试样有较好的黏结性,纳米SiO_2的引入对常温剪切强度影响不大,对高温剪切强度有显著影响,随纳米SiO_2质量分数的增加,200℃剪切强度先升高后降低,当纳米SiO_2质量分数为2%时,200℃剪切强度最高,为(20.5±0.4) MPa,强度保留率95.35%,另外,E-PTA-SiO_2胶黏剂耐湿热老化性也较E-PTA有所提高。     

阴离子清洁压裂液性能评价

阴离子表活剂压裂液是新型清洁压裂液,为了深入了解该压裂液的作用机理,进行了多项实验研究,包括压裂液的配方优化,液体配制,耐温抗剪切性能,黏弹性及悬砂性,压裂液的滤失及岩心伤害实验,压裂液的破胶特性等等。实验结果证明,压裂液黏度可调性强,在100℃条件下,压裂液的黏温、黏时性能及悬砂性好,压裂液遇到原油破胶,温度越高破胶越彻底,破胶后无残渣,伤害小。     

SiO_2/SDS复合体系CO_2泡沫驱油性能实验研究

以无机SiO_2纳米颗粒与SDS协同稳定的CO_2泡沫为研究对象,研究了该复合体系泡沫的耐温、耐油性能,并通过物理模拟实验研究了其驱油机理及性能。结果表明:复合体系中SDS质量分数为0.25%、SiO_2纳米颗粒质量分数为1.5%时,CO_2泡沫在80℃条件下半衰期可达25.3 min,相比较单一SDS体系CO_2泡沫半衰期延长23.8 min;原油体积分数10%时,复合体系CO_2泡沫半衰期相较于单一SDS体系CO_2泡沫延长18 min;复合体系CO_2泡沫对于附着在岩石壁面上的原油具有更为明显的"擦除"作用,这种作用与泡沫在多孔介质中的快速反复运动相结合能够进一步提高洗油效率;随着复合体系质量分数的增加,采收率增幅逐渐增加,当SiO_2纳米颗粒质量分数达到1.5%时,可提高采收率30.3%;22~80℃实验温度范围内,复合体系CO_2泡沫提高采收率均达到20%以上。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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