Steady-state and unsteady-state two-phase relative permeability hysteresis and measurements of three-phase relative permeabilities using imaging techniques
The objective of this work is to improve determination of two-phase and three-phase relative permeabilities by the use of saturation imaging techniques. The first part of the paper reports on steady-state and unsteady-state relative permeability experiments performed on restored-state carbonate reservoir cores. The aim was to study how relative permeability test methodology impacts relative permeability curves. hysteresis and residual oil saturations in these intermediate-wet cores. Refined oil was used. Significant hysteresis was observed in both the unsteady-state water and oil relative permeabilities. The characteristics of the unsteady-state water relative permeabilities imply that viscous instabilities were present during the waterflood. Centrifuge capillary pressure-wettability tests performed on companion core plugs both before and after the relative permeability tests showed good agreement with the unsteady-state results, but indicated change towards less oil-wetness during the steady-state tests. The main conclusion of this work is that extensive flushing of a restored-state core with refined oil may lead to a non representative relative permeability data and should therefore be avoided. The second part of the paper presents a summary of results obtained from three-phase unsteady-state flow in water-wet sandstone (Berea and Clashach) cores. In-situ saturation measurements show that the water relative permeability is dependent on water saturation alone, and that there is no change in water relative permeability due to three-phase flow. The waterflood residual oil saturation was found reduced in the presence of a gas phase, and may depend on the phase (oil or gas) injected prior to waterflooding.
- OSTI ID:
- 199482
- Report Number(s):
- CONF-951002-; TRN: 96:000706-0053
- Resource Relation:
- Conference: Annual meeting of the Society of Petroleum Engineers (SPE), Dallas, TX (United States), 22-25 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of Reservoir engineering. 1995 SPE annual technical conference and exhibition; PB: 1008 p.
- Country of Publication:
- United States
- Language:
- English
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