咸水层封存条件下CO2/盐水/岩石体系平衡润湿性的基础研究

The wettability of CO2/brine/rock system has decisive influence on key parameters and processes during CO2 dynamic migration such as capillary pressure and relative permeability. The study of equilibrium wettability is the beginning to investigate the wettability of CO2/brine/rock system. Under conditions for CO2 sequestration in saline aquifers, equilibrium wettability of CO2/brine/rock system is affected by multi sequestration parameters such as temperature, pressure, ions type, salinity and rock type. However, the law and the mechanism of the affection are still open to questions. In the current proposal, experiments will be performed to measure the equilibrium wettability of CO2/brine/rock system under different storage conditions to build a model to express the relationship between storage conditions and equilibrium wettability. Using this model, the law of the effects of storage conditions on equilibrium wettability of CO2/brine/rock system will be analyzed. Molecular dynamics simulation methods will be applied to capture the features how storage conditions modify equilibrium wettability of CO2/brine/rock system on molecular level. By analyzing these features, the mechanisms how storage conditions affect the equilibrium wettability of CO2/brine/rock system will be discovered. The successful actualization of this proposal will provide theoretical and data accumulation for solving the key scientific problem as law of CO2 dynamic migration and storage mechanism with multiple physical and chemical interactions and provide knowledge repertory for large scale CO2 sequestration in saline aquifers in future.

CO2/盐水/岩石体系的润湿性对毛细压和相对渗透等CO2动态运移过程中的关键参数和过程具有决定性影响，而平衡润湿性是研究CO2/盐水/岩石体系润湿性的基础。咸水层封存条件下，CO2/盐水/岩石体系的平衡润湿性受到温度、压力、离子种类、盐度和岩石种类这些封存条件的多重影响，但影响规律和影响机理不明。本项目采用实验方法研究不同封存条件下CO2/盐水/岩石体系的平衡润湿性，建立封存条件与CO2/盐水/岩石体系平衡润湿性的关系模型，分析封存条件对CO2/盐水/岩石体系平衡润湿性的影响规律，采用分子动力学模拟方法捕捉封存条件改变CO2/盐水/岩石体系平衡润湿性的分子尺度特征，阐明封存条件影响CO2/盐水/岩石体系平衡润湿性的机理，为解决多重物理、化学作用的CO2动态运移规律和封存机理这一关键科学问题提供理论和数据积累，为最终实现规模化咸水层CO2封存提供知识储备。

CO2/盐水/岩石体系的润湿性对毛细压和相对渗透等CO2动态运移过程中的关键参数和过程具有决定性影响。本项目采用实验和数值模拟方法研究了不同封存条件下，CO2/盐水/岩石体系的平衡润湿性，捕捉了封存条件改变CO2/盐水/岩石体系平衡润湿性的分子尺度特征。主要研究内容包括：（1）温度、压力、离子种类、盐度对CO2/盐水/岩石体系平衡润湿性的影响规律；（2）CO2/盐水/岩石体系分子动力学模拟模型的构建；（3）温度、压力、离子种类、盐度和岩石种类对CO2/盐水/岩石体系平衡润湿性的影响机理。项目研究工作圆满完成，并取得了显著的成果。人才培养方面，在本项目资助下，1名硕士研究生顺利完成答辩并获得学位，2名硕士研究生预计2016年6月答辩。国际合作交流方面，项目组负责人赴美国劳伦斯伯克利国家实验室学术访问交流一年，与国际顶尖研究团队建立了良好的合作关系，并合作发表论文1篇。共发表期刊论文3篇：《Environmental Science & Technology》（领域TOP期刊、中科院一区、影响因子5.33）、《International Journal of Greenhouse Gas Control》（中科院二区、影响因子3.946）、《Molecular Physics》（影响因子1.72）。构建了高温高压下CO2/盐水/岩石体系润湿性研究平台，并针对实验过程中及文献中遇到的问题，设计了能够调节温度探针及岩石表面测点位置的新系统，并申请国家发明专利1项。