Packer K J, Stapf S, Tessier J J, Damion R A
Department of Chemistry, University of Nottingham, UK.
Magn Reson Imaging. 1998 Jun-Jul;16(5-6):463-9. doi: 10.1016/s0730-725x(98)00071-x.
The determination, by pulsed field gradient (PFG) nuclear magnetic resonance (NMR), of the probability distributions (propagators) of displacements for fluids undergoing transport by both flow and self-diffusion within porous solids is outlined. The nature of the observed propagator, P delta (Z), for the transport of a single aqueous phase through an outcrop sandstone (Fontainebleau) is described. Recent measurements of the propagators for both aqueous and oil phase flow in the limiting saturation states of irreducible water (Swi) and residual oil (Sor) in the same sample are illustrated through the use of difference propagators. These are shown to emphasise the regions of the propagators most affected by the presence of the second, stationary, phases in these limiting saturation conditions. Measurement of the propagators for both oil and aqueous phases undergoing simultaneous flow are also described for the same sandstone sample and the effect of increasing Swi on the nature of the oil flow is briefly discussed. Finally, a new two-dimensional (2-D) experiment is introduced which measures the propagator P delta (X, Z). This is the joint probability for displacements X and Z in time delta. Some preliminary observations of these two-dimensional propagators are shown for single-phase flow in the Fontainebleau sandstone sample, where Z and X are, respectively, displacements in the axial and radial direction for the cylindrical sample for which the pressure gradient is along Z and where bulk radial flow is constrained to be zero.
概述了通过脉冲场梯度（PFG）核磁共振（NMR）测定多孔固体中流体在流动和自扩散共同作用下位移的概率分布（传播子）。描述了通过露头砂岩（枫丹白露砂岩）的单一水相传输所观察到的传播子Pδ(Z)的性质。通过使用差分传播子，展示了最近对同一岩样中在不可压缩水（Swi）和残余油（Sor）的极限饱和状态下的水相和油相流动传播子的测量结果。结果表明，这些差分传播子突出了在这些极限饱和条件下受第二固定相存在影响最大的传播子区域。还描述了对同一砂岩样品中油相和水相同时流动的传播子的测量，并简要讨论了增加Swi对油相流动性质的影响。最后，介绍了一种新的二维（2-D）实验，该实验测量传播子Pδ(X, Z)。这是时间δ内位移X和Z的联合概率。给出了枫丹白露砂岩样品单相流动中这些二维传播子的一些初步观测结果，其中对于圆柱状样品，Z和X分别是轴向和径向的位移，压力梯度沿Z方向，且总体径向流动被限制为零。
