天然气水合物岩石物理实验研究进展

天然气水合物是我国地质调查和资源勘查的重要矿体之一, 勘探开发面临着诸多难题, 如地震响应特征、力学和电学性质等需要开展深入研究。天然气水合物的赋存需要特定的温度和压力范围, 环境温度和压力的变化可能会造成天然气水合物的分解, 这在海洋环境和地质灾害等研究领域造成了诸多问题。天然气水合物地层的物性和岩石物理变化特征较复杂, 在实验室开展天然气水合物测试分析是了解其岩石物理性质、获取岩石物理参数的一种有效手段。回顾了凝水成冰法、四氢呋喃(THF)溶液法、过量水法、过量气法、温度法、冰粉混合法等实验室生成水合物的方法, 总结了温度、气体压力、粒径、矿物成分、含水率、表面活性剂、含盐量、地层骨架等水合物生成实验的影响因素, 介绍了水合物岩石物理实验研究中声学、力学、电学等方面的研究进展, 展望了天然气水合物岩石物理实验未来的研究方向。

Gas hydrates are an important type of mineral resources in geologic and resource surveys, but there are many challenges, e.g.unestablished seismic responses and mechanical and electrical properties, in hydrate exploration and development.Without appropriate ambient temperatures and pressures needed for gas hydrate occurrence, these solid compounds may decompose and then trigger marine environmental change and geologic hazards.An effective way to understand complicated rock physics of gas hydrates is lab tests.We review the synthetic methods including cooling and icing, THF solution, excess water, excess gas, temperature, and ice powder blending and the factors that may influence hydrate synthesis, e.g.temperature, gas pressure, particle size, mineral composition, water content, surfactant, salt content, and formation skeleton.We also discuss the progress in acoustics, mechanics, and electricity related to hydrate rock physical experiments and future efforts focusing on rock physical experiments.