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SAGD vs CSS vs mining

The three ways to get bitumen out of the ground.

Field guide entry · written September 23, 2026.

Mining

Truck and shovel. Where the deposit sits close to the surface, the overburden comes off and the oil sand goes to a hot-water extraction plant. Only about a fifth of the oil sands resource is shallow enough to mine; the rest needs wells. Mined projects: Horizon, Muskeg River, Jackpine, Kearl, Fort Hills, Suncor Base, and Syncrude's Mildred Lake and Aurora. Mines are the only source that feeds upgraders directly, and their output is flat by design until the pit moves.

SAGD

Steam-assisted gravity drainage. Two horizontal wells, one above the other. Steam goes into the top well and forms a chamber; heated bitumen and condensed water drain down to the lower well by gravity and get pumped up. It needs a thick, permeable reservoir and it is the dominant in-situ method: Foster Creek, Christina Lake (both Cenovus and MEG), Sunrise, Surmont, Jackfish, Kirby, Leismer, MacKay River, Firebag, Long Lake, Tucker, Orion, Lindbergh, Great Divide, BlackGold, Hangingstone, and Blackrod all use it. The key metric is steam-oil ratio: cubic metres of steam per cubic metre of bitumen. Canadian SAGD projects run cumulative ratios of roughly 2.5 to 6, with good operators around 3. Recovery can exceed half the oil in place, which is why SAGD won.

CSS

Cyclic steam stimulation, the original thermal method: huff and puff. Inject high-pressure steam into a well, shut it in to soak, then produce from the same well. Repeat. It works in reservoirs that do not suit SAGD, typically thinner pay. The trade is efficiency: late in a well's life the steam-oil ratio runs higher than SAGD. In Alberta it lives at Imperial's Cold Lake (the largest CSS project in the oil sands), CNRL's Peace River, and CNRL's Primrose.

Why it matters

Method sets the decline profile. SAGD pads decline and get replaced by new pads, so the project is a drilling treadmill. CSS wells cycle. Mines just run. When you see a project's forecast shape, you are mostly seeing its extraction method.

Sources

Heavy Reading · the WCSB supply letter.
Public information only: AER ST3/ST39/ST53 and company disclosures via the WCSB S&D model. Nothing here is licensed data, so this page renders the same with or without ?public=1.