Abstract Brazilian pre-salt reservoirs represent the discovery of large amounts of light oil, but at high pressures and containing high concentration of CO2. Proper parameter estimation procedures are essential to perform more accurate predictions of their thermodynamic properties. Therefore, two new methodologies for such calculations have been implemented here: by applying simultaneously VLE and LLE to the metric; and by handling water content in dew point conditions. Utilizing the Cubic-Plus-Association (CPA) EoS, they were employed to obtain new parameters for water. Also, new parameters were obtained for H2O + CO2 mixtures, whose average absolute deviation in water content at high pressures fell from 24% to 3% compared to previous publications. The same procedure was performed for other aqueous mixtures containing H2S and light hydrocarbons. Finally, this study has been applied into a natural gas compressing simulation with CO2, studying streams properties comparing the parameters obtained in this work with the literature.

中文翻译：

---

EoS 中参数估计的计算工具：新方法和天然气相平衡计算

摘要 巴西盐下油藏代表了大量轻质油的发现，但处于高压和含有高浓度 CO2 的状态。正确的参数估计程序对于对其热力学性质进行更准确的预测至关重要。因此，这里实施了两种用于此类计算的新方法：同时将 VLE 和 LLE 应用于度量；并通过处理露点条件下的水含量。利用 Cubic-Plus-Association (CPA) EoS，他们被用来获得水的新参数。此外，还获得了 H2O + CO2 混合物的新参数，与以前的出版物相比，高压下水含量的平均绝对偏差从 24% 下降到 3%。对含有 H2S 和轻质烃的其他水性混合物进行了相同的程序。