Wiley InterScience: Journal: Abstract

Abstract | References | Full Text: PDF (214k) | Related Articles

Research Article

Investigation of thin surface-wetting films in two-phase saturated porous media

William M. Holmes¹, Ken J. Packer^{2
*}

¹School of Chemical and Physical Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand
²School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK

email: Ken J. Packer (Ken.Packer@bluecom.net)

^*Correspondence to Ken J. Packer, The Beeches, 68 Cawston Road, Aylsham, Norwich NR11 65D, UK.

Keywords

PGSE NMR • two-phase • diffusion • porous media • spin-lattice relaxation

Abstract

Strongly water-wet porous solids were saturated with two immiscible phases, an aqueous and an hydrocarbon phase, in varying proportions. The porous solids studied were a sample of Fontainebleau sandstone and packs of monodisperse glass beads. The diffusive displacements of the aqueous phase (i.e. the wetting phase) were investigated using pulsed field gradient stimulated echo (PGSTE) NMR to measure the one-dimensional displacement probability distribution P(X). Measurements of P(X) are presented for the whole accessible water saturation range. At lower water contents the displacement distributions P(X) show a distinctive shape, which is attributed to the distribution of the aqueous phase in thin surface wetting films connecting pendular rings where the beads are in contact. The data are reproduced well by a random walk computer model based on such a geometry, the simulated propagators being very sensitive to the surface film thickness. The longitudinal relaxation times of the water phase were also measured and found to deviate from the fast diffusion model at low water saturations. Copyright © 2002 John Wiley & Sons, Ltd.

Received: 30 September 2002; Accepted: 4 October 2002

Digital Object Identifier (DOI)

10.1002/mrc.1130 About DOI