用不稳定试井资料研究油藏储集层流动系统模式：以准东油区为例

从不稳定试井Ｈｏｒｎｅｒ曲线形态分类入手，结合油藏动态特征对油藏储集层流动系统进行分类，并初步确定出各类流动系统的特征参数及其相应的开采特点。根据不稳定试井Ｈｏｒｎｅｒ曲线形态，可以把相应的储集层流动系统划分为三大类（孔隙流动系统、双重介质流动系统、裂缝流动系统）五个亚类。特别提出了双重介质孔缝串并流动系统组合模式。这无论对新区开发方案的编制，还是老区开发政策的制定都具有重要的借鉴参考价值。     

岩石爆破的逾渗模型

本文在分析几种典型的岩石爆破损伤模型的基础上，发现岩石爆破损伤演化具有明显的逾渗效应。采用逾渗来描述岩石爆破损伤断裂这一动态过程是可行的，并提出了进一步可能的研究途径。     

Influence of polymer modulus on the percolation threshold of latex-based composites

Monodispersed copolymer emulsions with different glass transition temperatures were synthesized to investigate the effect of room temperature polymer matrix modulus on the electrical properties of carbon black (CB) filled segregated network composites. The emulsion with the highest modulus at room temperature produced composites with the lowest percolation threshold. The threshold for a composite made from a copolymer latex containing an equal ratio of butyl acrylate and methyl methacrylate (BA5) is 1.5 vol%, while the percolation threshold for the much lower modulus BA7 (7:3 BA/MMA ratio) is 4.93 vol%. The microstructure of each composite shows significant differences in the level of CB dispersion within the polymer matrix. Higher modulus polymer particles push the CB more efficiently into the interstitial space between them, resulting in a lower percolation threshold. This modulus effect was confirmed by increasing the drying temperature, where the moduli of latexes (BA5, BA5.5, and BA6) were more similar and the percolation thresholds for three composites also become closer to one another.     

Preparation and rheology of polyamide-6/attapulgite nanocomposites and studies on their percolated structure

The polyamide-6/attapulgite nanocomposites were prepared via an in situ polymerization route with attapulgites pre-modified with cetyltrimethylammonium bromide (CTAB) and toluene-2,4-diisocyanate (TDI). Morphology observation showed that the exfoliated attapulgite fibers were well dispersed in the polyamide-6 matrix on a nanometer scale and formed a percolation network structure. The rheological behaviors of such polymer/fibrous clay nanocompostie samples were investigated by an ARES rheometer with parallel plate geometry. The storage moduli (G′), loss moduli (G″), and dynamic viscosities of these samples increased monotonically with attapulgite content at low frequencies. The presence of attapulgites caused these nanocomposite melts to have solid-like behaviors and slower relaxation. This behavior can be explained in terms of the development of a grafting-percolated fibrous-silicate network structure. Monte Carlo simulations were performed to determine the critical threshold for attapulgites fibers in 3D. The calculated critical threshold from simulations fitted the results of our rheological experiments very well.     

Mesoscale models of conductivity in polymeric electrolytes—A comparative study

The studies of conductivity behavior of composite polymeric electrolytes (CPE) have been widely realized for about 15 years. There is, however, a lack of a versatile and efficient model of conductivity in these systems. The effective medium approach was introduced to predict the conductivity of systems according to some previously defined mixing rules. The main limitation of this method, however, is the fact that each new composite microstructure forces a new mixing rule development. This paper presents the random resistor network approach as an alternative method to the effective medium theory based approach. The presented comparison of both methods is based on both dc and ac simulated conductivity data. Some experimental data are introduced to compare the models with the conductivity values obtained for real samples.     

Percolation and the resistive transition of the critical temperature Tc of Nb3Sn

The relationship between the distribution of the critical temperature, the percolation function, and the resistive transition of the critical temperature is explored for polycrystalline Nb₃Sn. In the neighborhood of the critical temperature, Nb₃Sn is assumed to be a random mixture of superconducting and normal grains. Percolation concepts are applied to a study of the resistivity. A general analysis is made showing that the onset and shape of the resistive transition for composite conductors are determined by the percolation function and the distribution of the critical temperature. An approximate form of the percolation function is determined based on a linear FEM analysis. Example resistive transitions are calculated for an assumed normal distribution of the critical temperature. An argument is presented that relates grain orientation and strain dependence in Nb₃Sn. It is noted that a dependence of the distribution of T_c with strain, in addition to the usual shift in T_c with strain, would be the result of a strain dependence that is a function of grain orientation. The analysis shows the extent to which the slope of the resistive transition is a measure of the distribution of the critical temperature, and therefore a measure of the grain orientation strain sensitivity. Finally, a method is described to determine the percolation function experimentally.     

Enhanced dielectric properties of bismuth titanate/silver composites

Bismuth titanate (BiT) based composites containing silver particles are fabricated by a solution chemical process. Incorporation of silver particles does not result in unwanted reaction phase. SEM micrographs reveal fine silver particles distribute at BiT grain boundaries and into larger BiT plate-like grains. With the addition of silver, the dielectric constant increases up to ∼10 times higher than that of pure BiT ceramic, which can be attributed to the effective electric fields developed around the dispersed metal particles and the percolation effect. Additionally, the dielectric losses are significantly reduced by incorporating silver particles, and the values of BiT/Ag composites are lower than 0.5%. The dielectric properties of BiT/Ag composites are nearly frequency independent in the measured frequency range (1 kHz to 1 MHz).     

A new method for recovering valuable metals from low-grade nickeliferous oxide ores

A new method, the concentrated sulfuric acid acidolysis and water leaching (SAWL) of nickeliferous oxide ores, is proposed and the optimal conditions for recovery of nickel, cobalt and copper from a low-grade Chinese nickeliferous oxide ore are presented. A series of experiments were conducted which examined the effect of acid charge, acid curing temperature and acid curing time. Recoveries of up to 95%, 83% and 95% for Ni, Cu and Co, respectively were obtained with only the sulfuric acid at ambient temperature and atmospheric pressure. Comparing the percolation leaching with agitation leaching showed that percolation leaching was capable of extracting the valuable metals with water. The SAWL method was scaled to three-stages counter-current leaching tests using 1 kg of ore. The results indicate greater than 90% extraction for nickel and cobalt.     

具有井筒相分离和层间窜流的层状油藏渗流井底压力精确解

关于具有窜流的多层油藏井底压力解，国内外有不少学者进行了研究，Ｄ．Ｂｏｕｒｄｅｔ提出的双渗模型最具实用性，但该模型在表皮系数为负时，数值计算极不稳定，应用受到限制，本文首次用有效井径概念，导出了一个数值计算相当稳定的双渗模型，另外还考虑了井筒相分离影响，本模型解大大扩大了Ｂｏｕｒｄｅｔ模型的应用范围。     

指进,剩余油形成与分布的物理模拟

在所建立的渗流平面物理模拟实验装置上，进行了不同油水粘度比，不同驱替速度下的水驱油实验。分析了指进、剩余油形成规律及对采出程度的影响。首次提出由于指进发育造成注入端及排液端附近的剩余油开采潜力，阐述了开采速度对采出程度影响的临界特性、回流现象、不规则渗流场中指进的自相似性，出口端油流量的波动等。对相关的剩余油开采措施及在生产中提高采出程度提出了一些新的建议。