Velocity and gravity effects in relative permeability measurements

There have been several studies on the effects of gravity and flowrate on laboratory relative permeability measurements. Most of these studies have concentrated on the effect of these parameters on the flooding front. Miller's (1983) data showed that the influence of these and other variables are not understood. The study found that the calculated recovery at breakthrough was different than the observed recovery at breakthrough. The calculated recovery at breakthrough was based on theory derived from Buckley-Leverett piston-like displacement. This study attempted to determine how gravity or core positioning and flowrate of the displacing fluid might be used to achieve a stable flooding front. A relative permeameter with unsteady-state flow was used for the apparatus. The core material was an unconsolidated silica sand. It is found that gravity has no significant effect on the difference between calculated and observed recovery at breakthrough. It is also observed that an increase in flowrate could increase the flooding front instabilities. Therefore as flowrate decreased the calculated and observed breakthrough approach a single value.