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胜利油田滨南采油厂到2011年已经连续12年上产,刚靠老区挖潜已无法保障上产的需要,所以滨南油田逐渐转向寻找隐蔽性油藏和深层低渗透油藏作为上产的主力阵地,但这些油藏开发难度很大,出油量少,必须进行油层的改造技术,所以压裂技术是油水井增产、增注的主要措施。 相似文献
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在低渗透砂岩储层中,识别微裂缝发育井段对于评价储层的意义很大。实验资料及已有的文献资料表明:在低渗透砂岩地层中微裂缝发育区井段的渗透性相对较好,井壁上能形成一定厚度的泥饼。基于此条件,利用泥饼的存在会使井壁反射的超声波能量降低原理。通过数值计算分析了四种典型低渗透砂岩地层条件下,在无泥饼时,及有泥饼时在不同泥饼厚度下超声波能量的降低程度;分析了采用分辨率高的声成像测井资料识别低渗透砂岩地层中的微裂缝发育区可行性;对比分析了在低渗透砂岩地层中的微裂缝发育区实际声成像资料的特征。并利用实际资料验证了相应的理论计算结果,初步论证了利用声成像测井资料可定性分析微裂缝的发育程度,定量分析有待进一步研究。 相似文献
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本文选择了十余种高分子聚合物制备了单一材料的均质膜,并在此基础上研究了五种不同的高分子材料共混体系的成膜以及气体渗透性能。 相似文献
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考古发掘出土的风化骨质文物通常疏松多孔、力学强度低、质地脆弱,易出现翘曲、开裂、酥粉化等现象,亟需探索脆弱骨质文物加固保护的新方法。本研究采用羟基磷灰石前驱材料氧化钙-磷酸氢钙的醇分散液渗入脆弱骨质内部,再用蒸馏水渗入引发氧化钙与磷酸氢钙反应而生成羟基磷灰石连续相。该连续相能填充脆弱骨内部的孔隙和裂缝,并通过桥连黏接而加固骨质。利用电镜、能谱、XRD、色差、质量、孔隙率、密度和断面强度等研究考察了悬浮分散液中氧化钙与磷酸氢钙的质量配比(1:1、1:3、1:4、1:5、1:6、1:7)和施加方式(刷涂、滴渗和浸泡)对加固效果的影响,结果表明,悬浮分散液中氧化钙和磷酸氢钙的质量配比为1:3,且施加方式为刷涂时,加固处理效果最佳。经加固处理后,脆弱骨的孔隙率下降了17.3%,质量、密度和表面强度分别提高了38.39%、34.49%和16.32%,且其色差△E也小于3.0,符合文物保护要求。本研究为脆弱骨质文物的加固保护提供了新的有效方法。 相似文献
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随着油田的勘探开发,多数油田已进入高含水开发期,采收率低,开发效果差,为保持油田的稳产、高产,特别需要对老油田进行精细油藏描述,对剩余油进行调整和挖潜,而砂岩储层极细颗粒粒度的精确测定,对未来老油田的挖潜,特别是对低渗透油藏提供了可靠的依据。 相似文献
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为了更好地揭示饱和细粒砂岩在不同孔隙水压力作用下的损伤本构关系,基于损伤力学/概率统计方法和有效应力原理,采用MC强度准则假定微元强度服从对数正态分布,建立了基于统计损伤理论的饱和细粒砂岩本构模型,修正了统计损伤模型参数F_0、S_0与孔隙水压力之间的关系表达式,建立了能够更加客观地反映饱和细粒砂岩损伤状态的本构模型。理论与试验对比研究表明所建立的模型具有一定的可靠性,在此基础上,研究了统计损伤模型参数F_0、S_0对饱和细粒砂岩物理特征的影响,探讨了饱和细粒砂岩在不同围压、不同孔隙水压力下的损伤演化规律,为实际工程案例中饱和细粒砂岩的损伤变化提供了参考。 相似文献
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ZHENG Qiang ZUO Min PENG Mao SHEN Lie FAN Yurun 《Frontiers of Materials Science in China》2007,1(1):1-6
Rheological measurement has been a preferred approach in the characterization of the formation and evolu-tion of microstructures for multi-component or multi-phase polymeric material systems owing to i... 相似文献
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In this paper we consider the structure and properties of polymeric materials possessing spatial gradients as well as potential applications of such materials.These gradients may be generated by varying the chemical nature of the monomers, the molecular constitution of the polymers and the supramolecular structure or morphology of the polymers. Gradients in each of these categories are possible for single-phase as well as heterophase systems. Such gradients are associated with gradients in properties.The properties considered are chemical, mechanical, biomedical and transport properties. Structural gradients in the polymeric system may lead to a desired gradient in a single property, or to a combination of more than one property which may assume optimum values in different regions of the material. In the latter case, one of the properties is frequently related to mechanical integrity.Possible applications of gradient polymeric systems include platic gasoline tanks, biomedical implants, and damping materials for a wide frequency range. 相似文献
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We present excellent polymeric buffer materials based on the poly(9,9-dioctylfluorene-co-N, N-di(phenyl)-N,N-di(3-carboethoxyphenyl)benzidine) (BFE) for highly efficient solution processed organic light emitting diodes (OLEDs). Doped BFE with 3,5-dinitrobenzonitrile (35DNBN), a strong electron acceptor results in significant improvement of current flow and driving voltage. Maximum current- and power-efficiency value of 7.2 cd/A and 5.5 lm/W are demonstrated from blue OLEDs with these doped polymeric anode buffer system. The 40 nm thick anode buffer material showed a similar current density-voltage (J-V) behavior to that of PEDOT:PSS based device. Results reveal a practical way to fabricate the highly efficient solution processed devices for low cost production of printing devices for the future. 相似文献
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Nanoporous polymeric materials are porous materials with pore sizes in the nanometer range (i.e., below 200 nm), processed as bulk or film materials, and from a wide set of polymers. Over the last several years, research and development on these novel materials have progressed significantly, because it is believed that the reduction of the pore size to the nanometer range could strongly influence some of the properties of porous polymers, providing unexpected and improved properties compared to conventional porous and microporous polymers and non-porous solids.In this review, the key properties of these nanoporous polymeric materials (mechanical, thermal, dielectric, optical, filtration, sensing, etc.) are analyzed. The experimental and theoretical results obtained up to date related to the structure–property relations are presented. In several sections, in order to present a more compressive approach, the trends obtained for nanoporous polymers are compared to those for metallic and ceramic nanoporous systems. Moreover, some specific characteristics of these materials, such as the consequences of the confinement of both gas and solid phases, are described. Likewise, the main production methods are briefly described. Finally, some of the potential applications of these materials are also discussed in this paper. 相似文献
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导热高分子材料研究进展 总被引:32,自引:0,他引:32
讨论了提高聚合物导热性能的途径-合成高导热系数的结构聚合物,用高导热无机填料对聚合物进行填充复合。综述了导热高分子材料的研究成果:聚合物导热的基本概念和影响其导热性能的因素及导热系数的预测理论;聚合物基导热复合材料的选材、复合技术及其应用。指出了导热高分子材料的研究方向--纳米导热填料的研究和开发;聚合物树脂基体的物理化学改性;聚合物基体与导热填料复合新技术的研究和开发;复合材料导热模型的建立、导热机理(特别是聚合物基体与导热填料界面的结构与性能对材料导热性能的影响)及导热通路的形成等;探索高导热本体聚合物材料的制备方法和途径等。对导热高分子材料的研究和开发有重要意义。 相似文献
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We have considered the problem of the dynamic stress redistribution in fibrous materials brought about by the failure of a single element. Our model consists of a number of aligned adjacent chains of harmonically coupled masses. Neighboring masses on adjacent chains are also coupled by shear-carrying springs. Depending upon the scope and assignment of parameters, the model might apply to aligned polymer chains in a crystal or amorphous environment, to filaments in a fiber, or to a fibrous composite material. At time t = 0, an intra-chain spring is broken and the motion of the masses in the local environment is followed by molecular dynamics. The dynamic loads carried by bonds in chains neighboring the defect oscillate with decreasing amplitude, ultimately reaching asymptotic values that can also be calculated exactly by harmonic analysis. We find that the maximum of the excess load carried by a spring in a chain adjacent to a defect is about two times the asymptotic value for two-dimensional arrays of chains and somewhat larger for three-dimensional arrays. The dependence of these quantities on the magnitude of the shear carrying spring constant is explored. These results have implications for a number of theoretical approaches to fiber and composite strength which use load-sharing models based on asymptotic values. 相似文献
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Abrasive wear behaviour of polymeric materials 总被引:2,自引:0,他引:2
In this study the abrasive wear behaviour of aliphatic polyketone (APK), polyoxymethylene (POM), ultrahigh molecular weight polyethylene (UHMWPE), polyamide 66 (PA66), and 30% glass fibre reinforced polyphenylenesulfide (PPS + 30%GFR) engineering polymers at room temperature were studied. Pin-on disc arrangement wear tests were carried out at 1 m/s test speed and load value of 10 N. Tests were carried out for 50, 100, 150 and 200 m sliding distances. Emery paper grid varying from 150 to 1200 grade were used as an abrasive disc surface. After each test the mass loss of the pin was recorded. Finally the specific wear rates were deduced from wear volume of the pin for test duration distances of 50, 100, 150 and 200 m. The results showed that the highest wear rate is for POM with a value of 8.5 × 10−4 mm3/N m and the lowest wear rate is for UHMWPE with a value of 3.36 × 10−5 mm3/N m. Furthermore, for all materials the wear rate increases linearly with increasing wear duration distance. 相似文献
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S. T. J. Peng 《Journal of Materials Science》1985,20(6):1920-1928
In a previous paper, a constitutive equation of relaxation behaviour of time-dependent chemically unstable materials has been developed by employing the irreversible thermodynamics of internal variables and Eyring's absolute reaction theory. In that paper, a theoretical expression for the effect of chemical crosslink density,v, on the relaxation rate has been developed. In this paper the creep behaviour of a network polymer undergoing a scission process has been developed. The temperature effect using the WLF equation on the coupled chemomechanical behaviour has also been incorporated into the equation. 相似文献