Canadian heavy crude prices have fallen to their weakest level relative to US oil futures since 2018, when a major pipeline bottleneck led Alberta’s government to limit production by the province’s largest producers.

Western Canadian Select’s discount in Alberta to the monthly average of West Texas Intermediate futures widened to $31.70 per barrel early Tuesday, according to prices from Modern Commodities and General Index. That was the largest discount since November 2018.

Canadian Cold Lake, a secondary benchmark, also traded at a steep discount on the US Gulf Coast. Its $23.10-per-barrel gap was at levels not seen in eight years.

Sources: Bloomberg Markets.