煤层存在瓦斯水合物的可能性

Possible existence of gas hydrate in coal bed

瓦斯气体在煤储层中的赋存状态主要有游离态、吸附态和溶解态。从瓦斯原始地质赋存条件分析了瓦斯水合物形成必需的物质条件和热力学条件,提出了其赋存的一个新的状态———瓦斯水合物态。利用水合物实验设备对合成瓦斯在2组含煤溶液体系中的生成过程进行研究,得到了瓦斯水合物生成的诱导时间、生成速度及生成时的热力学参数。将瓦斯赋存条件同实验模拟结果进行比较,结果表明:在中高纬度矿区的煤层中有瓦斯水合物自然存在的可能。若瓦斯自然赋存水合物态真实存在,其赋存区煤层应力场、温度场等将发生较大变化,这有利于降低煤矿瓦斯事故的发生频率。

The existing mine gas in coal bed occurs mostly in the free state, the adsorption state and the dissolved state. A new existing status-gas hydrate state is studied in this paper. The analysis of the material conditions and the thermodynamic conditions is based on the initial geologic conditions of the existing statuses of mine gas and the study of the formation processes of synthesized gas hydrate in three reaction systems added with coal by using the hydrate experiments yields the induction time, the formation rate and thermodynamic parameters. The comparison between the initial geologic conditions of the existing statuses of mine gas and the experimental data indicates the possibility that the gas hydrate in coal bed occur in the mine field located in the high-middle latitude district. The actual existence of the gas hydrate state and the consequent changes in the stress field and the temperature field of the gas hydrate storage area serve to reduce the occurrence of the mine gas accidents.