Nuclear-magnetic-resonance relaxation due to the translational diffusion of fluid confined to quasi-two-dimensional pores

Abstract

Nuclear magnetic resonance (NMR) relaxation experimentation is an effective technique for non-destructively probing the dynamics of proton-bearing fluids in porous media. The frequencydependent relaxation rate T to-bulk desorption rates for a thin pore. G(t) is found to decorrelate when spins move from the surface to the bulk, display three-dimensional properties at intermediate times and finally show a bulk-mediated surface diffusion (Lévy) mechanism at longer times. The results may be used to interpret NMR relaxation rates in hydrated porous systems in which the paramagnetic impurity density is negligible.

A model for the interpretation of nuclear magnetic resonance spin-lattice dispersion measurements on mortar, plaster paste, synthetic clay and oil-bearing shale

“…The expressions required to describe all the combinations of spin-pair interactions which contribute to the relaxation dispersion for a specific system have been presented [8,9]. The 3τ model is applied to four systems: an oilbearing shale (water and oil), a plaster paste, mortar and saponite clay.…”

“…The plaster and clay systems test the 3τ model for systems where paramagnetic impurities are absent and so the relaxation rate is associated with the interactions between spins in the surface monolayer and the bulk. The underlying theory, the fitting process and detailed analyses have been presented [8,9]. A summary of the results is presented in Table 2 together with the outcomes of the original analysis.…”

“…By placing the effective paramagnetic layer below the surface, the long-time limit of G(t) decays as t −2 (rather than t −1 when all spin species are contained in a pure 2D layer) leading to fundamentally different T −1 1 dispersions and a different value of the time constant τ when the model is fit to experimental data. The t −2 dependence of G(t) has been previously demonstrated theoretically and computationally [6,8,9]. A second innovation is that we integrate across the full thickness of the fluid to correctly account for the strong distance-dependence of the dipolar interaction.…”

Theoretical investigation of heterogeneous wettability in porous media using NMR

“…Groups led by Korb, Godefroy and Faux applied different models to interpret the T 1 dispersion using fast field cycling NMR (FFC-NMR) 26 – 30 . Faux et al .…”

Multi-Quanta Spin-Locking Nuclear Magnetic Resonance Relaxation Measurements: An Analysis of the Long-Time Dynamical Properties of Ions and Water Molecules Confined within Dense Clay Sediments

“…As a consequence, numerous theoretical and experimental studies were devoted to that problem in order to quantify the influence of the geometrical and thermodynamical properties [31][32][33][34][35][36][37][38][39] of the porous media on the NMR relaxation mechanisms of their confined fluids. In addition to NMR relaxation measurements performed at a limited number of available magnetic fields [16,33], spin-locking relaxation measurements [16,33,[40][41][42][43] were initially performed to extend the investigation of the dispersion curves to lower magnetic fields.…”