天然气水合物成藏体系研究进展

基于近年来国内外冻土区和海域天然气水合物勘探成果，从稳定条件、气源、气体运移、有利储层这几个方面概述了水合物成藏体系的新进展。研究结果表明，地温梯度、海底表层温度、气体组分、孔隙水盐度等多种因素影响并控制了水合物的相平衡条件。全球已发现的水合物气体来源以生物成因气、生物成因−热成因混合气为主，热成因气体对水合物成藏的贡献得到了越来越多的重视。烃类气体以扩散、溶解于水和独立气泡的形式在沉积物中发生迁移，断层、底辟、气烟囱构造等为含气流体运移提供了有效的通道。归纳出六种水合物的产出特征和四种水合物的储层类型。通过对水合物成藏模式的总结对比，认为以地质构造环境差异而进行的成藏模式分类具有更好的代表性。

Research Progress in Natural Gas Hydrate Accumulation System

On the basis of gas hydrate exploration achievements in permafrost regions and marine environment in recent years, new progress of gas hydrate accumulation system is summarized in aspects of gas hydrate stability conditions, gas source, gas migration and reservoir rocks. The results show that the geothermal gradient, seabed surface temperature, gas composition, pore water salinity and other factors affect and control hydrate equilibrium conditions. Biological and biological-thermogenic gas are the main sources in the global hydrate reservoir. Thermogenic gas becomes an important role in gas hydrate accumulation system. The hydrocarbon gas migrates in the sediments by diffusion, gas dissolved within migrating water, and as a separate bubble. Faults, diapirs, gas chimney and other similar structures provide effective channels for gas fluid migration. Six different types of hydrates and four hydrate reservoir rocks are introduced based on hydrate features occurrence around the world. According to analysis on different gas hydrate accumulation models, the classification of the accumulation model on the basis of different tectonic environments is a better representative.