从科研中提炼出的精细化工专业实验:新型疏水缔合聚合物的制备、表征及性能测定*

结合教师科研项目,推荐一个精细化工专业实验:疏水缔合聚合物的制备、表征及性能测定。通过该实验可以使学生掌握自由基共聚法制备聚合物的基本原理,掌握一些大型仪器的基本操作、聚合物常用的表征手段及结构分析方法,理解疏水缔合聚合物结构与性能之间深层次的理论联系。该实验项目来源于科研,服务于实践,集聚合反应、结构表征、大分子溶液理化性能测试于一体,具有综合性、前沿性、研究性等特点。本实验的开设有利于提高精细化工方向学生的专业实验水平,提升学生的综合探究素质、创新意识及动手能力。     

水中爆炸激波对水泥试样作用的数值模拟分析

通过对水中爆炸激波在水泥净浆试样中传播的数值模拟,再现了爆炸激波的传播过程,采用对典型单元受到的激波作用和应力进行分析的方法,得出了水泥试样各个区域损伤破坏的成因,数值模拟结果和实验现象吻合。     

高速通道压裂裂缝的高导流能力分析及其影响因素研究

高速通道压裂是近年在非常规致密油气资源开采中出现的新工艺, 已在世界范围内推广实施, 并取得了良好的增产效果. 该技术可使支撑剂在人工压裂缝中形成簇团式分布, 从而形成油气高速流动通道, 提高裂缝的导流能力. 但目前对于高速通道压裂裂缝高导流能力的形成机理及其影响因素尚不清楚. 对此, 本文从流体力学理论出发, 首先将高速通道压裂裂缝内形成的支撑剂簇团视为渗流区域, 簇团间的大通道视为自由流动区域; 然后基于Darcy-Brinkman方程建立了裂缝内的流动数学模型, 采用均匀化理论对该流动数学模型进行了尺度升级, 推导得到了高速通道压裂裂缝的渗透率, 揭示了其高导流能力的形成机理; 并以此为基础, 分析了不同支撑剂簇团形状、大小以及分布方式等因素对其导流能力的影响, 可为高速通道压裂工艺参数设计与优化提供基础.     

水平井变质量流研究进展

综述了水平井筒沿管壁具有流体流入的变质量流动的最新研究 进展.内容包括:考虑油藏流体流入时井筒流动压力及产量的计算,具 有不同流入时管壁摩擦系数的经验计算公式,以及流体径向流入井筒 后流动阻力损失产生的机理分析等.重点介绍了水平井筒变质量流动 阻力系数的计算,同时文中还介绍了井筒两相变质量流动损失产生的 机理和数值模拟研究进展.     

Flow-induced polymer degradation probed by a high throughput microfluidic set-up

A complex fluid submitted to strong flows can endure irreversible changes in its structure. This is the case for long chain polymer additives that are commonly used as viscosity enhancers in industry, notably for oil recovery. These polymers break in solution when submitted to high deformation rates, eventually causing a serious viscosity loss. This problem of practical importance is though difficult to handle from a fundamental point of view given its complexity. We introduce here a new tool, based on microfluidic technology, for the screening of the degradation of solutions in the model situation of the flow through a constriction. We integrate two functions in a single set-up, a micro-fabricated constriction and an on-chip viscosimeter. This tool enables us to probe rapidly the viscosity loss imparted by flowing through the constriction at a given flow rate. Thanks to microfluidics, the sample preparation and measurement time are significantly lower than those implied by classical measurement protocols (reduction by up to two orders of magnitude). In addition, confinement provides control of the flow in terms of inertia. To illustrate the potential of this approach in a screening perspective, we use this tool to study the degradation of a series of semi-dilute aqueous solutions of PEO of varying molecular weights and concentrations. For each solution we identify a threshold flow rate for polymer degradation. The corresponding critical deformation rate decreases with molecular weight and concentration, as expected (the mass dependence is in line with previous reports and theories for dilute solutions). In addition we characterize the viscosity loss for larger deformation rates and find that, despite the polydispersity of our solutions, the observations for the various solutions can be roughly recast on a master curve by renormalization of the imposed deformation rates according to a law $M_w^{?1.7\pm 03}{c}^{?0.7\pm 03}$.     

THE LIE SYMMETRIES AND CONSERVED QUANTITIES OF VARIABLE-MASS NONHOLONOMIC SYSTEM OF NON-CHETAEV''''S TYPE IN PHASE SPACE

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Split least‐squares finite element methods for non‐Fickian flow in porous media

In this article, we introduce two least‐squares finite element procedures for parabolic integro‐differential equations arising in the modeling of non‐Fickian flow in porous media. By selecting the least‐squares functional properly the presented procedure can be split into two independent subprocedures, one subprocedure is for the primitive unknown and the other is for the flux. The optimal order convergence analysis is established. Numerical examples are given to show the efficiency of the introduced schemes. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013     

稠油油藏试井理论研究

分析研究国内外稠油热采模型文献资料,总结归纳了9种稠油热采模型,主要包括非牛顿流体均质地层模型、二区复合模型、三区复合模型、多区复合模型、考虑重力超覆的数学模型以及干扰分析等,并对部分压力变化曲线及压力导数变化曲线做了简要的分析.比较各模型的优缺点,并指出目前的模型存在的问题以及稠油试井的发展趋势.     

不同喷嘴组合超高压射流破岩钻进特性分析

本文对不同喷嘴组合方式时超高压射流井底流场特性进行数值模拟.根据得出的井底流场的速度矢量图和井底压力分布图,分析超高压钻头喷嘴组合形式对流场结构及钻进效果的影响.结果表明,三个垂直的边喷嘴组合破岩效率较高,但清洗井底效果不佳,冲蚀井壁严重;中心加一个喷嘴可解决清洗井底及冲蚀井壁的问题,但要求高压流体排量增加;两个垂直边...     

高等数学多媒体课堂教学浅议

从使用多媒体讲授高等数学的经验出发,分析高等数学教学中应用多媒体教学手段的优势,同时给出在多媒体教学条件下进一步提高教学效果的几点建议,指出教师必须用现代化的教学思想为指导,综合运用各种教学手段提高高等数学教学效果,适应现代化教学的发展.