低渗低温低压水敏性储气层压裂改造技术研究与应用

低渗低温低压水敏性储气层因压裂液快速破胶困难、黏土膨胀水敏伤害严重和压后压裂液返排动力不足等因素，使得压裂增产面临诸多难题。针对上述难题进行了技术攻关，形成了弱交联、低温活化剂与超量破胶剂的低温储层快速破胶技术、有机盐与无机盐双元体系复合防膨技术以及高比例液氮全程助排的排液技术。该压裂增产改造技术使牛101井头屯河组首次获得工业油气流，扩展了三塘湖盆地勘探空间。     

致密低渗透气田的试井特征分析--以新场气田为例

经对新场气田的试井资料处理,建立了不同类型储层典型井试井解释范例,得出低渗透试井判别式和判别图版,对该区具有低渗透特征的试井曲线进行了讨论。根据试井结果,可识别气藏(气层)储集类型,确定产层物性参数,为气藏动态分析提供基础资料。为开发致密低渗砂岩气藏、保持稳产高产奠定基础。     

特低渗透油藏驱替及开采特征的影响因素

应用非达西渗流理论和非线性弹性渗流理论，分析了影响特低渗透油藏驱替及开采特征的主要因素。研究结果表明，启动压力梯度和毛细管压力是影响特低渗透油藏驱替特征的主要因素；而影响特低渗透油藏开采特征的主要因素是储层的弹塑性，即储层的压力敏感性。在特低渗透油藏的开发中应适当缩小注采井距提高驱替压力梯度，采取整体压裂措施减小启动压力梯度，通过气驱或活性水驱油减小毛细管压力，及时补充地层能量以减少压力敏感性对储层的伤害。     

钌基厚膜电阻传导模型初探

介绍钌基厚膜电阻的三种传导模型。三种模型都可以得到较满意的R—V曲线，不足处是链模型得出电阻率和导电相粒子形状及尺寸的关系和实验事实不符；有效介质模型不能反映厚膜电阻形成过程中众多因素的影响；渗透模型很多参数的获得有赖经验公式。渗透模型能反映烧结过程中更多因素的影响，并可解释方阻与导电相粒度及峰值温度的变化关系。     

安塞低渗油田孔隙结构对渗流特征曲线的影响

渗流曲线的测定是认识油藏流体渗流规律的基础。实验发现安塞油田储集层岩心渗流曲线在低有效净围压下近似表现为两段直线，通过压汞实验和毛管压力曲线数据分析，认为这种特征与储集层孔隙结构有关。在分析渗流特征时应综合考虑孔隙结核特征、流体与孔隙介质的相互作用等因素。     

TiB2与BN复相陶瓷的渗流模型

试验结果证实,TiB₂与BN复相陶瓷的导电性能符合渗流理论,原料粉粒度配比下,其渗流阀值为V_c%=22.9%;原料粉粒度比的改变将改变渗流阀值,从而改变各配比下的电阻率值;TiB₂与BN在SPS系统中快速烧结,晶粒的尺度比与原料粉的粒度比基本保持一致。     

Magnetic properties of high-temperature superconductors: Analysis within the framework of the impurity mechanism

The impurity mechanism proposed earlier is used to interpret the magnetic properties of hightemperature superconductors. The appearance of superconductive granules and the existence of weak bonds in grains of ceramics and in single crystals is explained. The irreversibility line is obtained and its new interpretation as the line of thresholds of appearance of infinite nonsuperconductive cluster is given. The relaxation time of the magnetic susceptibility in alternating magnetic fields is calculated. The decrease of the Meissner fraction with increase in magnetic field and decrease in doping, and other magnetic properties are explained.     

Effect of the particle size ratio on the conductivity of conductor-insulator powder composites: Numerical simulation

A theoretical method for determining the percolation limit and effective conductivity of composites based on polydisperse mixtures of insulator and conductor powders is proposed. The effect of the particle size ratio between the insulator and conductor on the percolation limit and effective conductivity is studied. Numerical simulation of the microstructure, effective properties, and percolation limit in composites is discussed. __________ Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 1–2(453), pp. 31–40, 2007.     

Two-Dimensional Whisker Percolation in Ceramic Matrix–Ceramic Whisker Composites

A computer model that treats ceramic-powder matrix–ceramic whisker composites as a percolative network of whiskers has been developed. The model calculates the critical fraction of whiskers at the percolation threshold for a two-dimensional random network of whiskers. The computed critical fraction was found to display an inverse dependence on whisker aspect ratio. In addition, the computed critical fraction (27 vol% for a whisker aspect ratio of 7) agreed well with the zero-shrinkage whisker fraction of 30 vol% in the densification of a colloid-pressed alumina–silicon carbide composite that exhibited a two-dimensional orientation of such whiskers.     

大规模认知无线电网络的时延分析

时延作为无线网络的最基本的性能之一,对网络信息分发、路由协议设计、节点部署等都具有重要意义。与传统的无线网络不同,认知无线电网络的频谱资源具有动态变化性,该特性会对网络时延产生极大的影响。因此,如何对动态频谱环境下的大规模认知无线电网络进行时延分析,是一项很具挑战性的课题。为此,首先对动态频谱环境进行建模,将认知用户的频谱接入过程建模为一个连续时间的马尔可夫链,并建立认知用户的生存函数来量化授权用户活动以及信道数量对频谱环境的影响;其次,将上述模型与首次通过渗流理论结合起来,研究了大规模认知无线电网络时延的伸缩规律,并获取了更为精确的时延与距离比的上限值。理论分析及仿真结果表明,动态频谱环境与密度一样会对时延产生极大影响。研究结论对认知无线电网络的设计具有重要的指导意义。