Investigation of two phase flow and phase trapping by secondary imbibition within Fontainebleau sandstone.
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.
Holmes
William M
WM
School of Chemical and Physical Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand.
Packer
Ken J
KJ
D019015:Geologic Sediments; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010578:Petroleum; D012212:Rheology; D014867:Water
D010578:Petroleum; D014867:Water