中文摘要：

自由水盐度直接影响水合物的生成和分解,为了充分研究自由水盐度对甲烷水合物相平衡的影响,本文利用正交实验设计方法研究了不同离子组成和浓度条件下多孔介质中水合物形成与分解特性。运用正交法研究水合物可减少实验次数、缩短实验周期。甲烷水合物相平衡点通过定容压力搜索法测得。与纯水体系相比,添加离子后相同压力条件下甲烷水合物的平衡温度降低,并且随着离子浓度的增加,平衡温度进一步降低。方差分析证明阳离子中Mg^2＋对水合物平衡影响最显著;极差分析结果表明,阳离子的影响程度从大到小依次为Mg^2＋、Ca^2＋、Na^＋、K^＋。SO4^2-、CO3^2-、Cl^-三种阴离子浓度对水合物相平衡点影响均显著。水合物诱导时间变化无明显规律,受离子种类、浓度影响不显著。

英文摘要：

The salinity of free water affects directly the formation and decomposition of methane hydrate. The phase equilibrium of methane hydrate in porous media under the condition of different compositions and concentrations of anions and cations was studied by using the orthogonal experimental design. The experimental results showed that the equilibrium temperature of methane hydrate under the same pressure conditions would decrease with the presence of ions. The increase of ions concentration would cause the gradual decrease of equilibrium temperature. Analysis of variance demonstrated that only Mg^2＋ had significant influence on the equilibrium point of methane hydrate. The influences of the concentration of three anions on the equilibrium point of methane hydrate were all significant. The induction time of methane hydrate was irregular and was rarely affected by the kind and concentration of ions.