To extract oil that is too deep for surface mining operations, in situ mining, or “in place” mining, is used. Mining companies use steam and gravity to bring the sticky oil to the surface. This method is used where the oil sand layer is deeper than 75 meters (246 feet).
Two parallel L-shaped wells reach into the deep oil sand deposit. One injects steam through holes in the pipe. This warms the oil and lowers its viscosity. The oil then flows down to the well below where it’s pumped to the surface.
This method is not as visible in the Landsat images as the surface mining is. Each well needs a “well pad,” a small area of boreal forest cleared. A growing number of small dots appear in a grid pattern over the time series images. A vertical line appears near the top of the 2009 image. This airport was built to fly in workers close to the mining sites.
Again, a Sentinel-2 image from September 29, 2016, shows the area in slightly finer detail at 20-meter resolution. The dots that represent well sites appear a little sharper in this view.