中文摘要：

该文将段振豪及合作者建立的单气体溶解度模型推广到混合气体系，建立了能够计算CO2-CH4-N2-C2H6-H2S混合气体在电解质水溶液中溶解度的热力学模型。本模型将DMW92方程扩展到上述多组分混合气体系并使用其计算气体组分的逸度系数，采用Pitzer活度系数模型描述液相并沿用段振豪及合作者以前确定的纯CO2、CH4、C2H6和H2S的溶解度模型参数，而纯N2的溶解度模型参数由本研究确定。由于本模型不包含依赖混合气体溶解度实验数据确定的参数，因此对混合气体溶解度的计算是预测性的。通过与实验数据的对比，证实了本模型能够在宽广的温度、压力范围内准确预测CO2-CH4-N2-C2H6-H2S混合气体在水溶液中的溶解度（对于CO2和CH4的摩尔百分数超过90%的混合气体，本模型适用于273~523 K和0~2000×105 Pa的温压范围）。本模型的计算表明，相对于纯CO2气相，少量CH4、N2或H2S的加入会降低CO2的溶解度。对于CO2-H2O-NaCl型流体包裹体，少量CH4的加入会增大流体包裹体的均一压力。相关的计算程序可从通讯作者处获得。

英文摘要：

This study extends the solubility model developed by Duan and coworkers for pure CO2, CH4, C2H6, and H2S to the CO2-CH4-N2-C2H6-H2S gas mixture. The DMW92 equation of state （EOS） was extended to the CO2-CH4-N2-C2H6-H2S gas mixture by evaluation of interaction parameters between dissimilar molecule pairs from experimental VLE or PVTx data of binary gas mixtures. The extended DMW92 EOS was used in this model to calculate fugacity coefficients of components in gas mixture. The Pitzer model was used to calculate activity coefficients of gas dissolved in aqueous solutions. Solubility parameters determined by Duan and coworkers for pure CO2, CH4, C2H6 and H2S were followed and solubility parameters for pure N2 were determined in this study. Because this model contains no parameters evaluated from solubility data of gas mixtures, it is predictive for solubility of gas mixtures. Comparison with experimental data available shows that this model can predict solubility of CO2-CH4-N2-C2H6-H2S gas mixtures in aqueous solutions with high accuracy over a wide P-T range （For CO2 and CH4 dominant gas mixtures, the P-T range of this model is from 273 to 523 K and from 0 to 2000×105 Pa）. Calculations of this model indicate that the solubility of CO2 decreases with adding small percentage of CH4, N2 or H2S. The homogenization pressure of CO2-H2O-NaCl fluid inclusions will increase with adding CH4. The computer program based on this model can be obtained from the corresponding author.