Planned maintenance at several large refineries in the Midwest has decreased the volume of crude oil processed in the region, which has resulted in lower prices of Western Canadian Select (WCS), a crude oil typically processed in the Midwest. WCS crude oil is typically priced lower than other crude oils because of differences in crude oil quality, but increasing production of WCS and pipeline capacity constraints in Western Canada have resulted in even lower prices of WCS compared with crude oil benchmarks such as Brent.