孟庆国,刘昌岭,李承峰,等. 祁连山冻土区多组分气体水合物形成过程实验研究[J]. 海洋地质前沿,2022,38(1):72-79. DOI: 10.16028/j.1009-2722.2020.128
    引用本文: 孟庆国,刘昌岭,李承峰,等. 祁连山冻土区多组分气体水合物形成过程实验研究[J]. 海洋地质前沿,2022,38(1):72-79. DOI: 10.16028/j.1009-2722.2020.128
    MENG Qingguo, LIU Changling, LI Chengfeng, et al. Experimental study on the forming process of multi-component gas hydrates in Qilian Mountain permafrost area[J]. Marine Geology Frontiers, 2022, 38(1): 72-79. DOI: 10.16028/j.1009-2722.2020.128
    Citation: MENG Qingguo, LIU Changling, LI Chengfeng, et al. Experimental study on the forming process of multi-component gas hydrates in Qilian Mountain permafrost area[J]. Marine Geology Frontiers, 2022, 38(1): 72-79. DOI: 10.16028/j.1009-2722.2020.128

    祁连山冻土区多组分气体水合物形成过程实验研究

    Experimental study on the forming process of multi-component gas hydrates in Qilian Mountain permafrost area

    • 摘要: 祁连山冻土区天然气水合物气体组成复杂,储层裂隙发育,研究其形成过程对准确理解该区域天然气水合物的形成机制具有重要意义。基于祁连山冻土区水合物的气体组成配置了多组分气体,并对其在纯水、水合物矿区水及冻土岩芯介质体系中的水合过程进行了实验观测,获得了不同条件下多组分气体水合物的诱导时间及聚集形态特征,探讨了不同反应介质(水样盐度、沉积介质)对多组分气体水合物形成过程的影响。结果表明,冻土岩芯中多组分气体水合物的形成诱导时间较溶液体系更短,水合反应更快。多组分气体水合物呈现“松针状”“发丝状”“块体状”等多种形态,并优先在气液界面和反应釜内壁形成聚集,其形成过程呈现明显的“界面优势”特征,即冻土岩芯孔裂隙表面以及矿区水中悬浮颗粒为水合反应提供了除气液界面和反应釜壁外的“第三界面”,有效加快了多组分气体水合物的形成过程。

       

      Abstract: Multi-component gas hydrates are widely distributed in the fractured layers of the Qilian Mountain permafrost area. It is of great significance to the study of forming processes of the multi-component gas hydrates and better understanding of the formation mechanism of the natural gas hydrates in the Qilian Mountain area. Copying the gas samples released from the Qilian Mountain gas hydrates, multi-component gas samples were artificially prepared. Based on the visual observations under different temperature-pressure conditions, the formation processes of multi-component gas hydrates were respectively studied in pure water, mine water samples and sediment cores collected from Qilian Mountain hydrate deposit area. Based on the morphological characteristics of the multi-component gas hydrates, the influences of different reaction media (mine water salinities and sediments) on the formation of multi-component gas hydrates are discussed. In the pure water system, the multi-component gas hydrates are formed in various forms, such as pine needle, hair filament and block, which appear preferentially at the gas-liquid interfaces and the vessel wall. Compared to the pure water, the formation induction times of multi-component gas hydrates in the mine water samples collected from Qilian Mountain permafrost area were relatively short, suggesting that the low salinity mine water samples have no obvious inhibition on the hydrate formation processes. The induction time of multi-component gas hydrates formation in the Qilian Mountain cores was shorter and the hydration rate was faster than those in solution systems. It is obvious that, the formation processes of multi-component gas hydrates in the Qilian Mountain media shows a feature of "interface priority ". The fracture surfaces of Qilian Mountain cores and the suspended particles in the mine water samples provide the "third interfaces" besides the gas-liquid interfaces and the vessel wall for the hydration reactions, which effectively accelerate the formation processes of multi-component gas hydrates.

       

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