Shell Canada, a unit of Royal Dutch Shell , has warned customers synthetic crude volumes from its 255,000 barrel per day Scotford, Alberta, upgrader may be reduced in November and potentially December, trading sources said on Monday.
A Shell spokeswoman declined to comment.
In a separate incident, the Syncrude oil sands project in northern Alberta has also told customers it will cut synthetic crude volumes by around 5 percent in November, two trading sources said.
Syncrude has capacity to produce nearly 350,000 bpd.
A Syncrude spokesman did not immediately respond to a request for comment.
(Reporting by Nia Williams and Catherine Ngai; Editing by Cynthia Osterman)