利用地热开采海底天然气水合物

天然气水合物在资源、环境和全球气候变化中具有重要意义，因而引起各国的高度重视，已成为当代地球科学和能源工业研究的一大热点。近年来，能源短缺日益严重，油气价格居高不下，使得很多国家都更加关注具有能量密度高、储量大和分布广等特点的天然气水合物，纷纷加大天然气水合物勘探和开发研究的力度。海域中发现的水合物数量占绝大多数，因此开采海底天然气水合物是未来研究的重心。现有的多种天然气水合物开采方案，如热激法、减压法、化学抑制剂法、置换法和混合开采法等，都不同程度地存在一些问题。文章在对这些开采方法优缺点进行分析的基础上，提出了利用干岩地热开采海底天然气水合物的设想，并给出了相应的简单生产模型。只要解决好漏失、循环通道和换热面等人工地热储构建问题，利用地热开采海底天然气水合物将是未来商业生产的一个不错选择。

UTILIZING GEOTHERMAL ENERGY TO EXPLOIT MARINE GAS HYDRATE

Natural gas hydrate (NGH) plays important role in resource, environment and even global weather change, which has attracted great attention by many countries in the world. How to extract NGH has become the highlight for study on geosciences and energy industry. Especially in recent years because energy seems severely short and oil & gas price is higher and higher in the fast developing world, many countries have turned their attention to NGH with the traits of high energy density, large reserves, and wide-ranging distribution, trying every means to study on how to discover and extract NGH. Because most of NGH have been found in the sea area, exploitation of them under the sea has been concentrated in the future. Several exploitation methods for tapping NGH have been suggested, such as thermal activation, pressure releasing, chemical inhibitor, replacement and slurry mining. However, all those methods mentioned above have such-and-such problems to some extent. On the basis of analyzing the advantages and disadvantages of these methods, this paper introduces an idea of utilizing dry and hot rocks to exploit marine gas hydrate, and correspondingly gives a simple production model. If succeed in resolving such issues as leakage, cycling passage and surface of heat exchange in building underground boiler, utilizing geothermal energy to extract marine gas hydrates will possibly be a good choice for commercial production in the future.