中文摘要：

作为一种非常规能源,天然气水合物,俗称“可燃冰”,是一种重要的能源载体.国外在海底和永久冻土层都发现了天然气水合物藏,我国也在神狐海域和祁连山冻土区获得了含天然气水合物的岩芯.然而,天然气水合物资源的安全高效开采方式已成为天然气水合物藏开发利用的“瓶颈”,也是天然气水合物开采研究的热点和难点问题.本文在全面综述国内外天然气水合物开采研究的基础上,重点关注了CO2置换开采天然气水合物的研究进展,提出了采用CO2置换开多年采冻土区天然气水合物中CH4的设想,并分析了该方法的热力学和动力学可行性;最后,指出了CO2置换开采冻土区天然气水合物尚存在的问题和今后的发展方向.

英文摘要：

Natural gas hydrate,a kind of non conventional energy,known as the “Flammable Ice”,is an important energy carrier having good prospect of energy potential.Natural gas hydrate has been discovered overseas in permafrost region onshore and sea？ oor sediments.Core of rock containing natural gas hydrate has also been discovered in the Shenhu marine area and Qilian permafrost of China.However,the safe and highly effcient exploitation method has become the “bottleneck” in the exploitation of natural gas hydrate resource and has received much research interest.This paper summarizes the existing exploitation methods of natural gas hydrate,and focuses on the research progress of the exploitation method of CO2 replacement.Then the idea of replacing CH4 from methane hydrate with CO2 in exploiting natural gas hydrate in frigid permafrost region onshore is presented,and the feasibility of this method is analyzed based on kinetics and thermodynamics.Lastly,the potential problems and development directions in CO2 replacement of natural gas hydrate in permafrost region are presented.