Fast-Field-Cycling (FFC) NMR relaxometry is a powerful tool to analyse water properties in disordered porous media such as salt crusts. It probes the return of the macroscopic nuclear magnetization to its equilibrium state along an external magnetic field after a perturbation . The return to equilibrium of the magnetization, quantified by the so-called spin-lattice relaxation time T 1 , is induced by fluctuations in local magnetic fields, which in fluids occur primarily due to two effects: the rotational tumbling of individual molecules, which is responsible for intramolecular relaxation, and (2) the relative translational motion of molecules, which is responsible for intermolecular relaxation. For fluids confined in nanoporous media, a decrease in T 1 for increasing surface-to-volume ratio S/V is generally observed . For a slit pore of size h = V /S, one expects 1