The price for Western Canada Select – a blend of heavy oil sands crude and conventional oil – fell 3% last week to close at the lowest levels since February.
The effective price for bitumen-derived oil from Alberta’s oil sands is now $57.25 a barrel.
West Texas Intermediate (WTI) dropped 1.8% to below $94.65 a barrel on the New York Mercantile Exchange Friday.
A US Energy Department report issued Wednesday said oil stocks climbed by 4.1 million barrels over the past week, the sixth rise in a row.
North Sea Brent fell to $105.85 Friday.
The Athabasca deposit is the largest known reservoir of crude bitumen in the world and the largest of three major oil sands deposits in Alberta. The other two are the Peace River and Cold Lake deposits.
Together, the three oil sand deposits lie under 54,000 sq mi and contain about 1.7 trillion barrels of bitumen in-place — about equal to the world’s total proven reserves of conventional crude oil.