Introducing dimensionless parameters into the correlation of NMR relaxation time to transport properties of porous media

Abstract

Dimensionless parameters representing the viscous permeability (k) and NMR relaxation time (T 1 ) of particle beds, while accounting also for the particle size, are shown to improve drastically the accuracy of k-T 1 correlations in the slow diffusion regime, in the absence of bulk relaxation effects. The finding is based on a regression analysis of numerical results for k and T 1 in both random and ordered isotropic and anisotropic beds of fibers. Use of the formation factor (F ) improves further the accuracy of the correlations only for the strongly anisotropic unidirectional arrays of fibers. A survey of related literature reveals an extensive effort in recent years in upgrading k-T 1 correlations, driven primarily by applications in petroleum and gas field exploration and recovery.