中文摘要：

为揭示咸水环境中CO2与方解石相互作用的特点,选取方解石作为研究对象,设计在不同温压条件下（85℃,5.0MPa;135℃,5.7MPa;185℃,8.8MPa）进行了3组CO2-咸水-方解石的系列实验研究,重点探讨了方解石溶解现象的成因和温度对于方解石溶解程度的影响。实验前后岩样扫描电镜观察、反应液离子变化分析表明,实验后,3组实验中的方解石均表现出溶蚀坑、溶蚀带和溶蚀晶锥的溶解现象;方解石的溶解度在85℃时最低,185℃次之,135℃最高。研究结果表明,在含CO2的咸水中,方解石的溶解现象有溶蚀坑、溶蚀带和溶蚀晶锥,各自的分布规律及规模与温度有关。在含CO2的咸水中,方解石也具有各向异性的溶解特点。使方解石产生最大溶解度的温度峰值可能出现在135～185℃之间。超过这一温度,温度的升高会使方解石的溶解度下降。实验再现了方解石在咸水环境中的溶解、沉淀过程,对于CO2地质封存示范工程具有非常重要的意义。

英文摘要：

In order to reveal the features of the interactional function between the CO2 and calcite in saline water,this paper focuses on the cause of calcite dissolution and the impact of temperature on the extent of calcite dissolution,taking calcite as the object of study and carrying out three groups of experiment studies of CO2-saline water-calcite in different conditions of temperature and pressure.Before and after the experiment,the samples are observed with scanning electron microscope and the study of ion changes in the reaction liquid shows： after the experiment,the calcites in the three experiments all show the dissolution phenomena of corroded pits,corroded ridge and corroded cone.The solubility of calcite is the lowest at 85℃,higher in 185℃ and highest in 135℃.The above results indicate that in the saline water containing CO2,the calcite has the dissolution phenomena of corroded pits,corroded ridge and corroded cone,and each of their distribution law and scale is related to the temperature.In the saline water containing CO2,the calcite has an anistropic dissolution feature.The highest temperature resulting in the highest dissolution of the calcite may range between 135℃ to 185℃.If the temperature is above this value,the increasing temperature will lead to the decrease of the dissolution of the calcite.These experiments reproduce the process of the dissolution and precipitation of the calcite in the saline water environment and have significant effects on the demonstration project of CO2 geological storage.