作　　者： ; ; ; ;

机构地区： 中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室

出　　处： 《天然气地球科学》 2013年第2期265-272,共8页

摘　　要： 在半饱和含水态具有不同粒径、孔隙半径的人工、天然介质——硅胶、粉土内形成甲烷水合物,3支pF-meter探头测量反应过程中介质内垂直方向上不同位置处的基质势,据此计算分析介质内由水合物形成引起的水分消耗规律,进而探讨不同介质内甲烷水合物形成反应特征。通过实验发现,多孔介质的颗粒、孔径物理性质明显影响甲烷水合物的形成反应特征:水合物在具天然介质性质的粉土内的形成反应是一个长期持续过程,相反地,在硅胶内的形成反应过程较短且在硅胶内均匀形成;人工多孔介质——硅胶粉内的水合物形成反应速率维持恒定,天然多孔介质——粉土内的水合物形成速率由快减慢;甲烷气体由反应釜顶部注入,气体扩散进入介质顶层的速率最高,顶层介质内水合物形成速率略高于中、下层的形成速率;经历相同的形成条件,粉土内的最终水分转化率略高于硅胶内的最终水分转化率。 Methane hydrate was formed in the artificial and the natural media which had half-saturated moisture contents and different particle sizes and pore radiuses, and the artificial was chosen as silica gel powder and the natural was chosen as loess. During the reaction processes, the matrix potential values on different positions in the vertical direction of media were measured by three pF-meter probes. According to the measured values, the water depletion rules in the media caused by the methane hydrate formation reactions were calculated and analyzed and the characteristics of methane hydrate formation reactions in media were then studied. Experimental results show that the physical properties of different media-particle size and pore radius can obviously affect formation reaction characteristics of methane hydrate： the formation reaction process of methane hydrate in loess, complying with natural media properties,is perennial and durative, reversely, that in silica gel powder is ephemeral and uniform ; during reaction processes, the formation reaction rate within silica gel powder, artificial medium, keeps constant and that within loess, natural medium, slows down as reaction progressing; because methane gas was injected into substrate through reaction cell top, methane diffuses into top layer of substrate fastest and the hydrate formation reaction rate within there was slightly faster than those in both middle and bottom layers; undergoing the same conditions for methane hydrate formation, final water conversion rate in loess is slightly higher than that in silica gel powder. The above comparing result analyses also bring some reference values in geological aspect to us.

关 键 词： 甲烷水合物 形成 水分 颗粒性质 多孔介质

领　　域： [石油与天然气工程]