The characterization of fluid transport in a porous solid by pulsed gradient stimulated echo NMR
The characterization of fluid transport in a porous solid by pulsed gradient stimulated echo NMR
复制标题
通过脉冲梯度受激回波核磁共振表征多孔固体中的流体传输
DOI：
--
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
J. Tessier
中科院分区：
文献类型：
--
作者：
K. J. Packer;J. Tessier
报道了脉冲磁场梯度刺激回波核磁共振测量在枫丹白露砂岩样品中水相的流动和扩散。在固定观测时间Δ下，利用受激回波对梯度脉冲面积q的依赖关系推导位移概率分布P Δ(X)，其中X为场梯度方向，与驱动流动的施加压力梯度平行或垂直。P Δ(X)的形状作为Δ的函数是根据一组随机定向的毛细血管内的层流来建模的。对于小的Δ，分子大部分停留在它们开始时占据的毛细血管内Δ，因此，小的Δ的P Δ(X)受毛细血管的定向分布支配。对于大Δ， P Δ(X)的演化只有在引入分子在毛细血管内的速度梯度上的扩散，以及d…
Pulsed magnetic field gradient stimulated echo NMR measurements are reported for the flow and diffusion of an aqueous phase within a sample of Fontainebleau sandstone. The stimulated echo dependence on the gradient pulse area, q, for a fixed observation time Δ, is used to derive the displacement probability distributions, P Δ(X), where X, the direction of the field gradient, is arranged to be parallel or perpendicular to the applied pressure gradient driving the flow. The shape of the P Δ(X) as a function of Δ is modelled in terms of laminar flow within a set of randomly oriented capillaries. For small Δ, molecules remain largely within the capillaries they occupy at the beginning of the time Δ and, as a consequence, the P Δ(X) for small Δ are dominated by the orientational distribution of the capillaries. For large Δ, the evolution of the P Δ(X) is reproduced only when diffusion of molecules across the velocity gradients within the capillaries is introduced and, in addition, the fluid transfers between d...