Canada's missing barrels

The majors have carried billions of barrels of oil sands reserves on their books. The price downturn is making them disappear

This era of lower-for-longer oil prices has raised a thorny question for Canada's oil sands producers: at what point does oil in the ground cease to exist on the balance sheet? The answer is when the US Securities Exchange Commission (SEC) says so. The question became more acute after ExxonMobil was forced to write off 3.5bn barrels of its oil sands reserves in its annual 10-K filing. It amounts to the entire booked reserve base of its Kearl oil sands mine that was commissioned in 2013 at a cost of C$12.9bn ($9.81bn) and another 200m barrels of bitumen at its Cold Lake in situ project. The oil sands writedown slashed ExxonMobil's proved reserves by around 20%. ConocoPhillips followed suit, c