CO₂ sequestration in deep saline aquifers is a promising method to reduce atmospheric CO₂. The on-going CO₂CRC Otway project aims to demonstrate the effectiveness of large-scale CO₂ storage in deep saline formations and to develop new monitoring technologies in Australia. The relative permeability curves are essential for predicting the movements of CO₂ and estimate residual trapping in the aquifer during and after injection through numerical simulations. However, studies of relative permeability curves for the Paaratte sandstone at the in situ conditions are limited. In addition, different rock types in the Paaratte formation can behave differently when CO₂ displaces brine. This work reports four relative permeability experiments of CO₂/brine systems using the unsteady-state core flooding method for different types of rock collected from various depths of Paaratte formations at near-reservoir conditions. The relative permeability results calculated from the analytical Johnson, Bossler, and Naumann (JBN) method and the numerical history matching method are compared. The JBN method does not calculate the relative permeability accurately for CO₂/brine systems due to the assumptions of incompressible flow, since the CO₂ relative permeability results calculated from the JBN method are similar for all the cases. The history matching results show that the brine (water) relative permeability of the core samples with a high fraction of macropores is similar to the measurements for Paaratte formation reported in the literature over a large range of brine (water) saturation. In contrast, the brine relative permeability of the core samples with a high fraction of micropores is considerably higher than that of the core samples with macropores, suggesting better connectivity for the samples with a high fraction of micropores. The new findings will be useful in reservoir-scale numerical modelings of the Paaratte formation to more accurately predict the movement of CO₂ during and after the injection. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

---

近储层条件下Paaratte地层CO2-盐水多相流体相对渗透率测量

深部咸水层中的CO ₂封存是减少大气 CO _{2 的}一种很有前景的方法。正在进行的 CO ₂ CRC Otway 项目旨在证明在深部盐层中大规模封存CO ₂的有效性，并在澳大利亚开发新的监测技术。相对渗透率曲线对于预测 CO ₂的运动和通过数值模拟估计注入过程中和注入后含水层中的残余捕集是必不可少的。然而，对于原位条件下Paaratte砂岩的相对渗透率曲线的研究是有限的。此外，Paaratte 地层中的不同岩石类型在 CO ₂取代盐水。这项工作报告了 CO ₂ /盐水系统的四个相对渗透率实验，使用非稳态岩心驱替方法对从近储层条件下从不同深度的 Paaratte 地层收集的不同类型的岩石进行了实验。比较了从解析 Johnson、Bossler 和 Naumann (JBN) 方法和数值历史匹配方法计算的相对渗透率结果。由于不可压缩流的假设，JBN 方法不能准确计算 CO ₂ /盐水系统的相对渗透率，因为 CO ₂JBN 方法计算的相对渗透率结果在所有情况下都相似。历史匹配结果表明，具有高比例大孔隙的岩心样品的盐水（水）相对渗透率与文献中报道的在大范围盐水（水）饱和度范围内对 Paaratte 地层的测量结果相似。相比之下，具有高微孔比例的岩心样品的盐水相对渗透率明显高于具有大孔的岩心样品的盐水相对渗透率，这表明具有高微孔比例的样品具有更好的连通性。新发现将有助于 Paaratte 地层的储层规模数值模拟，以更准确地预测 CO ₂的运动注射过程中和注射后。© 2021 化学工业协会和 John Wiley & Sons, Ltd.