Various error sources exist in the specified relative permeability (k_r) curves for numerical modeling of CO₂/water core flooding process, including model selection, parameter estimation, and heterogeneity setting. In this study, we quantitatively investigate their effects on model predictions by a numerical sensitivity analysis. Numerical simulation results indicate: (1) The errors in residual gas saturation (S_gr) and residual liquid saturation (S_lr) could significantly influence the estimation of the total volume (TPV) of injected CO₂ when CO₂/water displacement reaches a steady state. A change of S_gr or S_lr by 0.1 can induce deviation in TPV up to 0.5 pore volume. (2) The change in S_gr could cause a bigger predictive deviation in local CO₂ saturation ( $S_{{\mathrm{CO}}_2}$) than that in S_lr. In the case of the same degree of change, the deviation of the former is almost twice as much as that of the latter. (3) The model predictions remain fairly consistent when utilizing either Corey's curve or Brooks–Corey curve, but become significantly different if changing to van Genuchten curve. In this case, the difference in TPV is greater than that caused by the errors in S_gr or S_lr. The maximum deviation in the predicted local $S_{{\mathrm{CO}}_2}$ exceeds 0.3, influencing the analysis of CO₂ local trapping behavior. Comparatively, the local $S_{{\mathrm{CO}}_2}$ buildup is only slight if van Genuchten curve is used, but obvious using Corey's curve. (4) k_r heterogeneity only presents a small effect on the local $S_{{\mathrm{CO}}_2}$ and could be reasonably ignored compared to the effects of the heterogeneity in capillary pressure and permeability. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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CO2岩心驱替数值模拟的相对渗透率曲线的不确定性和敏感性分析

在指定的相对渗透率（k _r）曲线中，存在各种误差源，用于CO ₂ /水芯驱替过程的数值模拟，包括模型选择，参数估计和非均质性设置。在这项研究中，我们通过数值敏感性分析定量研究了它们对模型预测的影响。数值模拟结果表明：（1）当CO ₂ /水驱替量达到a时，残余气体饱和度（S _gr）和残余液体饱和度（S _lr）的误差会显着影响注入的CO ₂总体积（TPV）的估计。稳定状态。的改变小号_克或S _lr达0.1会导致TPV偏差直至0.5孔体积。（2）S _gr的变化可能导致局部CO ₂饱和度的较大预测偏差（${\mathrm{小号}}_{{\mathrm{一氧化碳}}_2}$）比S _lr。在变化程度相同的情况下，前者的偏差几乎是后者的两倍。（3）当使用Corey曲线或Brooks–Corey曲线时，模型的预测仍然相当一致，但是如果更改为van Genuchten曲线，则模型的预测将显着不同。在这种情况下，TPV的差异大于S _gr或S _lr的误差所引起的差异。预测局部最大偏差${\mathrm{小号}}_{{\mathrm{一氧化碳}}_2}$超过0.3，影响对CO ₂局部捕集行为的分析。比较而言，本地${\mathrm{小号}}_{{\mathrm{一氧化碳}}_2}$如果使用van Genuchten曲线，则积聚很小，而使用Corey曲线则明显。（4）k _r异质性仅对局部影响很小${\mathrm{小号}}_{{\mathrm{一氧化碳}}_2}$与毛细管压力和渗透率异质性的影响相比，可以忽略不计。©2020年化学工业协会和John Wiley＆Sons，Ltd.