Abstract This paper presents an experimental study of gas condensate flow in porous media at pressures above the dewpoint pressure. Experimental studies of steady-state flows show that the gas flow rate starts to increase when the pressure significantly exceeds the dewpoint pressure (P = 1.74 Pс). The gas flow rate reaches its peak and is almost 30% higher than that near the critical point (P=Pc) at P = 1.5 Pс. Furthermore, the dependence of the gas flow rate on the pressure is non-monotonic and increased flow rates are reached when P = 1.4–1.74 Pс. The effect of wettability on the steady-state flow is considered. Changes in wettability do not increase the gas flow rate in the oleophobic porous media. A significant reduction of the hydraulic diffusivity of the porous medium occurs during unsteady-state flow when the pressure decreases. The observed effects are thought to be driven by formation of stable subcritical condensate nuclei, along with a slippage effect and changes in compressibility. The mechanism of stabilization of subcritical nuclei via combined action of the surface and electrical forces is considered and mathematical models that describe the experimental results are proposed.

中文翻译：

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多孔介质凝析气流中露点压力附近气体滑脱效应的产生机理

摘要 本文介绍了压力高于露点压力的多孔介质中气体冷凝液流动的实验研究。稳态流动的实验研究表明，当压力显着超过露点压力 (P = 1.74 Pс) 时，气体流速开始增加。气体流速达到峰值，比临界点 (P=Pc) 附近的气体流速高出近 30%（P = 1.5 Pс）。此外，气体流速对压力的依赖性是非单调的，并且当 P = 1.4–1.74 Pc 时达到增加的流速。考虑润湿性对稳态流动的影响。润湿性的变化不会增加疏油多孔介质中的气体流速。当压力降低时，在非稳态流动期间，多孔介质的水力扩散率会显着降低。观察到的效应被认为是由稳定的亚临界凝析油核的形成以及滑动效应和可压缩性的变化驱动的。考虑了通过表面力和电力的共同作用稳定亚临界核的机制，并提出了描述实验结果的数学模型。