多孔介质内泡沫稳定性定量评价实验

Quantitative Evaluation Experiment of Foam Stability in Porous Media

为了克服常规泡沫稳定性评价方法难以模拟高温高压多孔介质环境的不足,基于激光探测技术,根据激光透过不同衰变阶段泡沫时的透射性能差异,首次提出了一种高温高压条件下定量评价多孔介质内泡沫稳定性的实验方法。此外,为验证激光法评价结果的准确性,同时开展了泡沫粒径微观可视化实验,研究了压力、温度、多孔介质对泡沫稳定性的影响及其机理。结果表明,相同条件下,较无多孔介质,泡沫在多孔介质中的稳定性更好,且在高压条件下,多孔介质更有利于稳泡。原因是压力升高,孔隙受压缩其水力半径减小,空气与表活剂疏水链的分子间作用力增强,二者均会导致泡沫粒径减小,稳定性增强;升高同样温度,多孔介质中泡沫稳定性下降的幅度更大。是由于多孔介质中的固态颗粒导热系数比纯泡沫更高,单位时间内辐射出的热量更多,加剧了气泡膨胀及液膜排液,使泡沫粒径增大,稳定性降低。

In order to overcome the shortcomings of conventional foam stability evaluation methods that are difficult to simulate the high temperature and high pressure porous media environment, based on the laser detection technology, according to the difference in the transmission performance of the laser through the foam at different decay stages, an experimental method for quantitative evaluation of foam stability in porous media under high temperature and high pressure conditions is proposed for the first time. In addition, in order to verify the accuracy of the evaluation results of the laser method, the microscopic visualization experiment of foam particle size was carried out at the same time, the effects of pressure, temperature, and porous media on foam stability and their mechanism were studied. The results show that under the same conditions, the foam has better stability in the porous medium than no porous medium, and the porous medium is more conducive to bubble stabilization under high pressure. The reason is that the pressure increases, the hydraulic radius of the compressed pore is reduced, and the intermolecular force between the air and the hydrophobic chain of the surface activator is enhanced, both of which will lead to a decrease in the foam particle size and increased stability, increasing the same temperature, the foam stability decline in the porous medium is greater. It is because the thermal conductivity of solid particles in porous media is higher than that of pure foam, and more heat is radiated per unit time, which aggravates the expansion of bubbles and liquid film drainage, so that the foam particle size is increased and the stability is reduced.