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31.
Y.M. Al-Wahaibi C.A. Grattoni A.H. Muggeridge 《Journal of Petroleum Science and Engineering》2006,53(3-4):239-253
The changes in gas and oil relative permeabilities as miscibility is approached are of particular importance in multi-contact miscible displacements. These changes are a function of the detailed phase behaviour of the fluids and their physical properties as well as the properties of the porous medium itself.In this work, we investigate the behaviour of two-phase drainage and imbibition relative permeability curves of four, different, equilibrated fluid pairs from a three component, two-phase system (cyclohexene, isopropyl alcohol and water) that exhibits a critical point at ambient conditions. The tie-lines of these fluid pairs are at varying distances from the system's critical point. Equilibrium phase compositions and interfacial tensions (IFT) were determined for each of the four fluid pairs. Dynamic displacements were then performed in a linear two dimensional, bead-pack. Unsteady state, drainage and imbibition relative permeabilities were determined for the various pre-equilibrated mixtures. The experimental results show a clear change in relative permeability as the fluid pairs approach the critical point. As the interfacial tension decreases the non-wetting phase relative permeability increases more rapidly than the wetting phase relative permeability and hysteresis becomes less important.Two correlations [Coats, K.H., 1980. An equation of state compositional model: SPE J, 20 (5): 363-376.; Whitson, C.H., and Fevang, Ø., 1997. Generalized pseudo pressure well treatment in reservoir simulation. In Proc., IBC Conference on Optimization of Gas Condensate Fields.], commonly used to model the changes in relative permeability with interfacial tension, and the development of miscibility, were compared with the experimental data. The Coats correlation, which uses a single adjustable parameter to model the changes in both relative permeabilities and residual oil saturation as a direct function of the IFT, yielded an unacceptable match to the experimentally determined fractional flow. However the Whitson–Fevang correlation, which relates the changes in relative permeability to the capillary number using two adjustable weighting functions, presents a satisfactory match. 相似文献
32.
通过适当的工艺措施,采用Bridgman法生长了直径为30mm的X射线及γ射线探测器级的Cd.9Zn0.1Te晶锭.测试结果表明:该晶锭结晶质量良好,位错密度低,成分均匀,杂质含量低,红外透过率和电阻率都十分接近本征Cd.9Zn0.1Te的值.并从晶体的生长特性、缺陷和杂质的角度,分析了生长高性能晶体的条件,研究了生长Cdl-xZnxTe晶体的x值与缺陷和杂质浓度之间的关系. 相似文献
33.
The interfacial microstructures of 96 and 98% polycrystalline alumina joined with single crystal sapphire have been investigated in relation to the joining parameters. Joining has been evaluated based on either using a thin spin-on silica interlayer or by placing the alumina and sapphire in direct contact. The materials were joined by placing the coated or uncoated surfaces in contact and heating in the range of 1340–1475 °C with minimum external load. With the aid of a silica interlayer, sapphire and 98% polycrystalline alumina were successfully joined in 180 min at 1400 °C and above, while samples without a silica interlayer failed to join under these conditions. However, sapphire and 96% polycrystalline alumina were joined both with and without the use of silica interlayer. A variety of interfacial morphologies have been observed, including amorphous regions, fine crystalline alumina, and intimate contact between the sapphire and polycrystalline alumina. 相似文献
34.
文章对国内外开展微区薄层电阻测试的方法进行了综述,特别对改进范德堡四探针技术方法的测试原理、测试过程与测试结果进行了论述与分析,对微区电阻测试方法的进一步发展提出了一种可操作的方法,并研制出新型四探针测试样机。 相似文献
35.
做为一种耐磨性能很好的材料 ,SiC颗粒增强铝基复合材料切削加工表面具有分形特征。实际研究表明SiC颗粒增强铝基复合材料切削加工表面分形维数与抗磨损性能有密切关系 ,本文还分析了表面分形维数越大其抗磨损性能越强的机理。 相似文献
36.
Modified Imidazoles: Degradation Inhibitors and Adhesion Promoters for Polyimide Films on Copper Substrates 总被引:1,自引:0,他引:1
Polyimide films on copper substrates that are exposed to elevated temperatures and an oxidizing environment will be subject to degradation. In order to halt this degradation without changing the properties of the system, a polymeric agent could be placed between the polyimide and the copper. This paper will investigate three such materials that will not only slow down the degradation of the polyimide and the oxidation of the copper, but will also improve adhesion within the system. Fourier transform infrared reflection-absorption spectroscopy (FTIR-RAS) will be used to investigate the polyimide/polymeric agent/copper system. 相似文献
37.
By using scanning polarization force microscopy,the deliquescence process and the atomic steps on the cleavage surface of CaCO3 in air were studied in situ.Under an exposure to medium umidity(-57%),the sloiw step movement has been observed. 相似文献
38.
39.
Two thermoplastic and two thermosetting fibrereinforced plastic composites were subjected to dynamic tests over a wide range of temperature, covering both cryogenic and hot environments. The thermal behaviour of each composite, as indicated by its dynamic mechanical properties, was assessed individually, and was compared collectively with that of the other composites. 相似文献
40.
本文介绍了采金船渡汛时的停泊方向及采金船在洪水中可能产生拖曳力的估算方法,为了防止采金船汛期发生溜船事故,建议采用缆绳牵拉固船的措施,以保障采金船的汛期安全。 相似文献