Canadian Natural believes it holds some of the best oil sands assets in Canada, providing tremendous value and growth potential. Our thermal assets are located in two of the major oil sands deposits in Western Canada – the Athabasca and the Cold Lake deposits.
Thermal In Situ
Canadian Natural's oil sands deposits are in the form of bitumen, which in its natural state, is too viscous to flow. When bitumen is too deep (>80 m) to economically mine, steam is injected, reducing the oil viscosity and allowing it to be pumped through surface wells. Only about 7% of Canada's oil sands can be mined, the majority has to be recovered using thermal in situ recovery.
Within the Athabasca deposits, the McMurray reservoir is our primary target and steam assisted gravity drainage (SAGD) is the recovery process of choice. SAGD uses two well bores, one for continuous steaming and the other for continuous production. Within the Athabasca region, the majority of our assets are in the planning stages, which include Grouse, Birch Mountain, Ipiatik, Gregoire and Leismer. Kirby, the next phase of our Thermal Growth Plan began construction in late 2010 and is targeted to add 40,000 bbl/d of capacity with a targeted steam-in date of 2013.
In the Cold Lake deposits, we have our Primrose and Primrose East operations where we currently produce from the Clearwater reservoir using the cyclic steam stimulation (CSS) process. CSS uses a single well bore to inject and produce steam. This technology has been historically applied to reservoirs that have barriers to vertical flow. The production peaks and troughs at Primrose are a reflection of the cyclic steam process – the peaks are associated with production cycles from newer, less mature wells and the troughs are associated with production cycles from the more mature areas in the field.