Waterflood relative permeability was measured in Indiana limestone under five mixed-wet conditions,as characterized by macroscopic contact angles on polished calcite which ranged from ?w = 55? to 150?,and two Darcy velocities: Uw = 1.5 μm/s and 30 μm/s. Oil relative permeability at initial oil saturation decreased and brine relative permeability at residual oil saturation increased with increasing ?w under the conditions considered presently. Greater-thanone end-point relative permeability was observed at θw<90° for oil and at θw>130° for brine. End-point brine relative permeabilities were larger at the larger Uw under all oil-wet conditions considered,i.e.,?w>90?. In contrast to recent literature that associate greater-than-one permeability to the flow of non-wetting fluid against surface,we observed enhanced permeability even when the flowing fluid was the wetting phase. Our results demonstrate that models assuming kr ≤ 1 underestimate fluid displacement for a wider range of contact angles than previously documented
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