Low-Pressure SAGD Project
The first thing you need to know about the Clearwater Project is that it uses 100 percent underground or in situ extraction of the bitumen – it’s not a surface open-pit mine. Both phases of Clearwater use multiple pairs of horizontal wells drilled underground and employing steam-assisted gravity drainage (SAGD) to get at the bitumen. The surface footprint of Phase I is very small at barely 10 hectares, the facilities are modest in size – and there are no tailings ponds.
Clearwater uses an innovative version of SAGD to further increase operating safety. The steam will be injected into the reservoir at much lower pressure than is usual in SAGD projects – 1,000 kilopascals (kPa) maximum versus the normal 1,700-4,000 kPa. That much lower pressure reduces the underground stress on the cap rock that sits over the bitumen reservoir, greatly reducing the risk of any steam moving away from where it should be.