WCS pricing has related refinery issues. 850,000 boe of refining is off line in the united states right now, this is amost 3 times as much as is normally offline. The BP whiting refinery that normally has 413,000 boe of processing capacity is down until the end of October.
This refinery usually buy 250,000 boe of wcs daily.
The refinery will be back on line at the end of October.
BP Whiting Refinery IMHO