Laboratory Experiments and Simulations on the Significance of Non-Equilibrium Effect in the Capillary Pressure-Saturation Relationship
Laboratory Experiments and Simulations on the Significance of Non-Equilibrium Effect in the Capillary Pressure-Saturation Relationship
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DOI：
10.1007/3-540-26736-0_1
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Hassanizadeh;O. Oung;Sabine Manthey
中科院分区：
文献类型：
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作者：
S. Hassanizadeh;O. Oung;Sabine Manthey
最近的理论表明，毛管压力可能不仅是饱和度的函数，而且还可能取决于饱和度的时间变化率。这就是所谓的动态或非平衡效应。文献中有令人信服的实验证据表明，非平衡效应是可观察的，可量化的，而且很重要。然而，几乎所有报道的实验都涉及不饱和系统。在这项工作中，我们报告了最近一系列的实验，涉及水和PCE。准静态以及动态毛管压力曲线的主要排水，主要排水，和主要的吸胀，测量。利用这些数据估算了非平衡毛管压力系数。最后，一个连续尺度的两相流模型已被用来模拟实验。计算了平均压力和平均含水饱和度随时间的变化，并与实测曲线进行了比较。据发现，位移过程发生得更快，在模拟比在实验中。据信这是由于存在数值模型未捕捉到的动态效应。
Recent theories indicate that capillary pressure is perhaps not only a function of saturation but may also depend on the time rate of change of saturation. This is known as the dynamic or non-equilibrium effect. There is compelling experimental evidence reported in the literature that the non-equilibrium effect is observable, quantifiable, and significant. However, almost all reported experiments relate to unsaturated systems. In this work, we report on a recent series of experiments involving water and PCE. Quasi-static as well as dynamic capillary pressure curves for primary drainage, main drainage, and main imbibition, are measured. The data are used to estimate the non-equilibrium capillary pressure coefficient. Finally, a continuum-scale two-phase flow model has been employed to simulate the experiments. Variations of average pressures and average water saturation with time are calculated and compared with measured curves. It is found that the displacement process takes place much faster in simulations than in experiments. This is believed to be due to presence of dynamic effects not captured with the numerical model.