水合物共存体系中气体溶解度预测模型  

Predictive model on gas solubility in water-rich phase coexisted with gas hydrates

作　　者：汤涵 蔡进[1] 覃海航 陈光进[1] 孙长宇[1] TANG Han;CAI Jin;QIN Haihang;CHEN Guangjin;SUN Changyu(State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)重质油全国重点实验室,北京102249

出　　处：《化工学报》2024年第11期4348-4358,共11页CIESC Journal

基　　金：国家自然科学基金项目(22127812,21908243,U20B6005)。

摘　　要：准确预测气体在液相中的溶解度对研究气体水合物的稳定性和分解动力学具有重要意义。采用Valderrama-Patel-Teja状态方程和Wong-Sandler混合规则关联了CH4和CO_(2)在水相中的溶解度数据。为了进一步扩展至电解质溶液体系,考虑了Debye-Hückel静电力作用;由汽液相平衡数据和低压盐析系数拟合了气体-水、气体-电解质的交互作用参数。基于扩展的Patel-Teja状态方程与Chen-Guo水合物模型,预测了水合物共存体系下CH4和CO_(2)在纯水和电解质溶液中的溶解度。结果表明,理论模型计算结果与实验数据具有较好的一致性,纯水体系下二者的平均相对偏差分别为5.740%和3.530%;对于NaCl水溶液体系,其预测的气体溶解度平均相对偏差分别为2.340%和1.990%。模型可为海底CO_(2)水合物法固态封存、CO_(2)置换开采天然气水合物等技术开发提供理论参考。Accurate prediction of gas solubility in liquid phase is of great significance for studying the stability and decomposition kinetics of gas hydrates.In this work,the Valderrama-Patel-Teja equation of state in conjunction with the Wong-Sandler mixing rule was adopted in correlating methane and carbon dioxide solubility data.In order to improve the predicting ability of gas solubility for saline solutions,the Debye-Hückel electrostatic contribution was taken into account.Moreover,the gas-solvent interactive parameters were evaluated via experimental data of gas solubility in water and the ion-gas interactive parameters were obtained by fitting low-pressure salting-out constants.The modified Patel-Teja equation of state was then integrated with the Chen-Guo hydrate model and was employed to predict gas solubility in water and saline solutions in the presence of hydrate.Comparing with experimental data,the empirical or semi-empirical correlations indicates that the proposed model is capable of predicting methane and carbon dioxide solubility in water and salt containing systems in equilibrium with their hydrate.The average relative deviations of predicted solubility for CH4 and CO_(2)in water coexisting with hydrate are 5.740%and 3.530%,respectively.When the proposed method is used for saline solutions,the average relative deviations of calculated solubility for CH4 and CO_(2)are 2.340%and 1.990%,respectively.The proposed model,

关 键 词：气体水合物 热力学模型 溶解度 状态方程 电解质 

分 类 号：TE37[石油与天然气工程—油气田开发工程]