It's the principle of leaving less oil behind. When people talk about enhanced oil recovery, it's really accessing the oil that's left underground. The fracking technology that's opened up a number of the resources is very much based on using a well to reach out, if you will, to contact and produce more oil.
The addition of light hydrocarbon creates a miscibility with the oil itself. If you had a bit of tar on the side of your car, you might use some Varsol or gasoline to clean it off. Water won't do the job. Propane, ethane, and butane are natural constituents of natural gas. When added to steam, they leave less oil behind and improve the geometry of production so that the recovery factors increase. We have two drivers in the reservoir, like in a hybrid car, where you have a natural gasoline engine in addition to a battery. The light hydrocarbon will reflux or recycle within the reservoir. We can recycle it, and it will reduce steam-oil ratios by up to half.
It's at a commercial stage at Imperial Oil in Cold Lake, which really began in situ development. They have already gone commercial with a project they call LASER. At LASER, the program uses condensate, and they've seen reductions in steam-oil ratios of 25% as well as an increase in recovery by a little better than 40% overall. Their recovery factor went from 25% up to 35%. Probably most important, they've seen an increase in the rate of recovery. If things move more quickly, you waste less energy, and it's a much more efficient process.