钻井液与完井液2025，Vol.42Issue(1)：90-101,12.DOI:10.12358/j.issn.1001-5620.2025.01.010
考虑盐浓度的天然气水合物三维相平衡曲面热力学预测模型
A Thermodynamic Model for Predicting 3D Phase Equilibrium Surface of Natural Gas Hydrates Considering Salt Concentration
摘要
Abstract
Accurate prediction of the thermodynamic stability of gas hydrates in salt-bearing systems is of great significance for predicting the accumulation range and determining the decomposition domain of hydrate.Therefore,considering the non-spherical characteristics of hydrate crystal cavity and the electrolyte interaction in the salt-containing system,a thermodynamic model of gas hydrate phase equilibrium considering salt concentration was established,and compared with the experimental data.The results show that the established three-dimensional phase equilibrium surface can effectively predict the thermodynamic stability of NGH,and the absolute mean relative deviation of temperature is only 0.08 in pure water,and no more than 0.15 in salt.When the molar fraction of chloride is greater than 0.02 and the pressure is higher than 20 MPa,the chemical factors cause the p-T curve to shift.When the pressure is small,the equilibrium temperature changes dramatically along the gradient of salt concentration,and the p-T curve no longer has translation characteristics.At the same time,AlCl3 has stronger inhibitory effect on CH4 hydrate than other chlorine salts when the molar fraction is the same.The lnp-X-1/T three-dimensional surface of CH4 hydrate exhibits better Clausius-Clapeyron linear behavior locally,and the surface as a whole has certain nonlinear characteristics.Moreover,the better the inhibition effect of chloride electrolyte on CH4 hydrate,the stronger the nonlinear characteristics.关键词
天然气水合物/热力学模型/相平衡/Clausius-Clapeyron线性特征Key words
Natural gas hydrate/Thermodynamic model/Phase equilibrium/Clausius-Clapeyron linear behavior分类
石油、天然气工程引用本文复制引用
张更,李文拓,黄洪林,罗鸣,马传华,吴艳辉,李军..考虑盐浓度的天然气水合物三维相平衡曲面热力学预测模型[J].钻井液与完井液,2025,42(1):90-101,12.基金项目
国家自然科学基金青年科学基金项目"超深水超浅层气钻井溢流井下智能识别与井筒压力控制方法"(52104012) （52104012）
中国博士后科学基金资助项目"超深水超浅层气钻井地层-井筒耦合多相流动机理与溢流风险防控"(2024M753615) （2024M753615）
国家资助博士后研究人员计划"特超深井井筒多相流动机理与井下风险调控方法"(GZC20233105) （GZC20233105）
中国石油大学(北京)科研基金资助"超深油气井溢流早期智能监测与定量反演方法"(2462024XKBH006). （北京）
