油气藏评价与开发 ›› 2026, Vol. 16 ›› Issue (1): 61-73.doi: 10.13809/j.cnki.cn32-1825/te.2025313

• 方法理论 • 上一篇    下一篇

深部咸水层CO2地质封存相平衡参数修正模型

杨龙1,2,3(), 许寻1,3(), 郭立强1,3, 张艺钟4, 王坤1,3, 郑晶晶1,3   

  1. 1.中国石化中原油田分公司勘探开发研究院,河南 濮阳,457001
    2.中国石化中原油田分公司博士后科研工作站,河南 濮阳 457001
    3.中国石化酸性气田开发重点实验室,河南 濮阳 457001
    4.长江大学石油工程学院,湖北 武汉 430100
  • 收稿日期:2025-07-07 发布日期:2026-01-06 出版日期:2026-01-26
  • 通讯作者: 许寻(1974—),男,硕士,正高级工程师,从事油田开发、开发实验、提高采收率研究等工作。地址:河南省濮阳市华龙区中原东路360号,邮政编码:457001。E-mail:xvx.zyyt@sinopec.com
  • 作者简介:杨龙(1992—),男,博士,工程师,主要从事油气田开发研究工作。地址:河南省濮阳市华龙区中原东路360号,邮政编码:457001。E-mail:yanglong_ytze@163.com
  • 基金资助:
    中国石化科技部重点科研项目“中高渗油藏高含水期CO2驱多元防窜增效技术研究与应用”(P25138)

Correction model for phase equilibrium parameters of CO2 geological storage in deep saline aquifers

YANG Long1,2,3(), XU Xun1,3(), GUO Liqiang1,3, ZHANG Yizhong4, WANG Kun1,3, ZHENG Jingjing1,3   

  1. 1.Research Institute of Exploration and Development, Sinopec Zhongyuan Oilfield Company, Puyang, Henan 457001, China
    2.Postdoctoral Research Station, Sinopec Zhongyuan Oilfield Company, Puyang, Henan 457001, China
    3.Sinopec Key Laboratory of Acid Gasfield Development, Puyang, Henan 457001, China
    4.School of Petroleum Engineering, Yangtze University, Wuhan, Hubei 430100, China
  • Received:2025-07-07 Online:2026-01-06 Published:2026-01-26

摘要:

在咸水层CO2地质封存数值模拟中,气-水相平衡计算是获取气-水物性参数的核心环节,其准确性直接影响模拟结果的可靠性。目前的气-咸水相平衡模拟未充分考虑离子效应且未继承成熟的气-水相平衡框架,导致模拟可靠性不足。本研究旨在构建高精度CO2-咸水相平衡模型。基于摩尔守恒定律与逸度相等原则,创新性地构建考虑离子效应相平衡模型。通过对比实验数据验证模型准确性,并分析不同地层条件下深部咸水层CO2地质封存相平衡规律研究。研究结果表明:修正的物性参数可精准表征CO2在单盐-混盐溶液中的溶解度;建立的模型可以量化表征CO2-咸水相平衡计算关键指标(液相摩尔密度、气相摩尔密度、各组分摩尔组成、饱和度等);离子的存在导致液相中H2O摩尔分数上升而CO2摩尔分数下降,同时导致液相摩尔密度增大而液相饱和度降低;气相中组分组成和摩尔密度基本保持不变,但气相饱和度呈现上升趋势;离子浓度越大,对相平衡计算结果影响越明显,且Ca2+、Mg2+离子对于相平衡计算的影响明显大于Na+、K+。本研究构建的模型通过继承气-纯水体系框架并创新引入离子修正,突破传统模型局限,为深部咸水层CO2封存数值模拟提供高精度基础数据,对推动碳封存技术进步具有重要理论价值。该模型由气-纯水体系模型演化而来,具有良好的可拓展性。

关键词: 深部咸水层, 气-水相平衡, 摩尔守恒, CO2地质封存, 摩尔密度

Abstract:

In numerical simulations of CO2 storage sequestration in saline aquifers, calculating the gas-water phase equilibrium is a critical step for determining the physical property parameters of the gas-water system, and their accuracy directly affects the reliability of simulation results. Current simulations of CO2-brine phase equilibrium often inadequately account for ionic effects and fail to build upon established gas-water phase equilibrium frameworks, thereby compromising result reliability. This study aims to establish a high-precision CO2-brine phase equilibrium model. Based on the law of molar conservation and fugacity equality principles, an innovative phase equilibrium model incorporating ionic effects was established. The model accuracy was validated through comparison with experimental data, and phase equilibrium patterns during CO2 storage in deep saline aquifers under different formation conditions were analyzed. The results indicated that the modified physical property parameters could accurately characterize CO2 solubility in both single-salt and mixed-salt solutions. The established model could quantitatively describe key indicators in CO2-brine phase equilibrium calculations, including liquid-phase molar density, gas-phase molar density, component molar fractions, and saturation. The presence of ions increased the mole fraction of H2O while decreasing that of CO2 in the liquid phase. It simultaneously increased the liquid-phase molar density but reduced liquid-phase saturation. Gas-phase component composition and molar density remained essentially unchanged, while gas-phase saturation exhibited an upward trend. Higher ionic concentrations exerted more significant effects on phase equilibrium calculations. Notably, Ca2+ and Mg2+ ions exerted substantially stronger effects than Na+ and K+ ions. This model established in this study overcomes the limitations of traditional models by inheriting the framework of the gas-pure water system and innovatively introducing ionic correction. This study provides high-precision fundamental data for numerical simulation of CO2 storage in deep saline aquifers, offering significant theoretical value for advancing carbon storage technology. This model is derived from the gas-pure water system model and demonstrates good extendability.

Key words: deep saline aquifers, gas-water phase equilibrium, molar conservation, CO2 geological storage, molar density

中图分类号: 

  • TE375