title: Investigation of two phase flow and phase trapping by secondary imbibition within Fontainebleau sandstone.
abstract: Pulsed magnetic field gradient stimulated echo NMR is used to investigate the simultaneous flow of two phases (an aqueous phase and an hydrocarbon phase) within a strongly water-wet sample of Fontainebleau sandstone. The Fontainebleau sandstone is prepared in increasing steady-state water saturations by a secondary imbibition process. The increase in the water saturation causes an increasing fraction of the oil phase (non-wetting phase) to become trapped within the sample. The stimulated echo dependence on the gradient pulse area, q, is used to derive the displacement probability, PX, for a fixed observation time. These displacement probabilities clearly show the progressive trapping of the hydrocarbon phase with increasing steady-state water saturations. Quantitative measurements of the fraction of the oil phase trapped were made from the echo attenuation function Edelta(q), both as a function of water saturation and observation time.
authors.affiliation: School of Chemical and Physical Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand.
authors.forename: William M
authors.initials: WM
authors.lastname: Holmes
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Packer
mesh_terms: D019015:Geologic Sediments; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010578:Petroleum; D012212:Rheology; D014867:Water
chemical_list: D010578:Petroleum; D014867:Water