Experimental evidence of the existence of optimal injected steam mass flow rates to get the maximal water gravity drainage driven into steam chambers of different shapes

Based on a simple model theoretical, in this work we experimentally study the problem of gravity water drainage due to continuous steam injection into elliptical or circular porous chambers made of glass beads and embedded in metallic, quasi-2D, massive cold slabs. These configurations mimic the steam condensation, for a given time period, during the growth stage of the steam-assisted gravity drainage (SAGD) process, a method used in the recovery extra-heavy oil from homogeneous reservoirs. Our experiments validate the prediction of the theoretical model regarding the existence of an optimal injected steam mass flow rate, per unit length, φ', depending on the chamber shape, to achieve a maximum recovery of a condensate. We show that there are different and unique recovery factors, depending on the chamber's shape, when measured as the percentage of the mass of water recovered with respect to the injected steam mass. Our results can be extended to actual oil-saturated reservoirs because the model involves the formation of a film of condensates close to the chamber edge that allows for gravity drainage of a water/oil emulsion into the recovery well.