【摘要】 为了真实反映甲烷水合物的饱和度及其存在形式对沉积层渗透率的影响,利用自主研制的水合物合成与渗流试验一体化装置,制作天然砂土沉积层,研究沉积层的绝对渗透率随生成的水合物饱和度的变化规律。结果表明:水合物沉积层的绝对渗透率与水合物饱和度之间呈指数递减关系,在较低饱和度下即引起渗透率的急剧降低,随着饱和度的继续增加,曲线变得越来越平缓,在达到试验的最大饱和度时,绝对渗透率下降的幅度最大;水合物在沉积层中主要以占据孔隙中心的模式生成,水合物优先合成于大孔隙,甲烷气体分子优先与大孔隙中心的自由水分子生成水合物。更多还原

【Abstract】 For actually reflecting the influence of methane hydrates saturation and its existence form on the permeability of bearing sediments,using our own integration device of hydrate forming and seepage tests,the natural sand soil bearing sediments were prepared and the change law of absolute permeability of hydrates bearing sediments with the saturation of hydrates was studied.The experimental results show that the relationship between the absolute permeability of hydrates bearing sediments and the saturation of hydrates shows exponential decline,the permeability decreases sharply in lower saturation,meantime the curves become more and more gently with the increasing saturation of hydrates.The declining extent of absolute permeability is maximum when the saturation reaches the maximum value in this test.Hydrates were generated mainly by the form of taking up the pore center in hydrates bearing sediments,and they can preferentially form in the macropores.The molecules of methane gas can preferentially form hydrates with the free water molecules.更多还原