不同饱和度水合物沉积物的三轴加载渗透率试验

发布时间：2018-10-04 20:05

【摘要】：水合物沉积层的渗透率是影响天然气水合物开采效率的重要物性参数之一,为了探讨在天然气水合物开发过程中有效体积应力和水合物饱和度变化对含水合物沉积层渗透率的影响规律,选取天然粉砂土作为沉积物骨架,进行了不同饱和度水合物沉积物的三轴加载渗透率试验。结果表明:(1)当水合物饱和度恒定时,水合物沉积物的渗透率与有效体积应力呈负指数曲线变化规律,且曲线的斜率随着有效体积应力的增加由大变小;(2)在一定的有效体积应力条件下,水合物沉积物的渗透率随水合物饱和度亦呈指数递减规律变化;(3)有效体积应力和水合物饱和度变化对水合物沉积物渗透率的影响表现为非独立性,即随着前者的增大,后者对水合物沉积物渗透率的影响减弱,而随着后者的增加,前者对水合物沉积物渗透率的影响也减小。由此提出了有效体积应力和水合物饱和度对水合物沉积物渗透率的影响机理,即前者对渗透率的影响在于其对渗流通道的压缩作用,而后者对渗透率的影响则在于水合物对渗流通道的堵塞作用。
[Abstract]:The permeability of hydrate deposits is one of the important physical parameters that affect the recovery efficiency of natural gas hydrate. In order to study the effect of effective volume stress and hydrate saturation on the permeability of hydrate deposits during the development of natural gas hydrate, the natural silt sand is selected as the sediment skeleton. The permeability tests of hydrate sediments with different saturation were carried out under triaxial loading. The results show that: (1) when hydrate saturation is constant, the permeability and effective volume stress of hydrate sediment change in a negative exponential curve. The slope of the curve changes from large to small with the increase of effective volume stress. (2) under certain effective volume stress condition, The permeability of hydrate sediment changes exponentially with hydrate saturation. (3) the effect of effective volume stress and hydrate saturation on the permeability of hydrate sediment is non-independent, that is, with the increase of hydrate saturation, The effect of the latter on the permeability of hydrate sediments is weakened, but with the increase of the latter, the influence of the former on the permeability of hydrate sediments is also reduced. The influence mechanism of effective volume stress and hydrate saturation on the permeability of hydrate sediment is put forward, that is, the effect of the former on permeability lies in the compressibility of seepage channel. The effect of the latter on permeability is due to the blocking of percolation channel by hydrate.
【作者单位】：辽宁工程技术大学力学与工程学院;辽宁工业大学土木建筑工程学院;
【基金】：国家自然科学基金资助项目“超临界二氧化碳多脉冲气爆低渗透煤层抽采瓦斯增产机理研究”(编号:51574137) 辽宁工业大学教师科研启动基金“注热开采甲烷水合物过程中水合物分解—渗流—储层变形热流固三场耦合机理及数值模拟研究”(编号:X201403)
【分类号】：TE31

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