In a three dimensional scaled physical modeling experiment, Cold Lake oil sand was subjected to cyclic stimulation with supercritical ethane through a single horizontal injector/producer well located at the base of the reservoir. Hot ethane gas was injected into the bottom of the formation until the bottle hole pressure reached slightly above the ethane supercritical pressure of 4.9 MPa. Production of diluted bitumen followed the injection cycle through the same horizontal well until pressure in the reservoir was depleted slightly below 4 MPa. At that pressure liquid production rates were very low. During the experiment, temperature in the model varied considerably with the distance from the wellbore as well as with the number of stimulation cycles.

Supercritical ethane enhanced the cyclic solvent gas process by improving the early production rate. As well there was an increase of recovery of solvent in the blowdown at the end of the experiment. Both are important factors for the process economics.

Time animation of the temperature profile revealed that solvent gas preferentially invaded the region in close proximity to the production end of the horizontal well. The observation was consistent with the post test measurement of residual oil saturation in the model which showed that bitumen was preferentially depleted from that region. Evidently, full utilization of the horizontal well was not achieved in the experiment. Production enhancements would be expected if this technical deficiency could be overcome.

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