The update follows a fire over the weekend that damaged pipes, power and communication lines between two units of the Mildred Lake upgrader.
Synthetic crude oil will be produced at minimal rates for the next two weeks as part of a phased recovery strategy.
Synthetic crude is a light, easy-to-refine oil that is made by upgrading oilsands bitumen.
Canadian Oil Sands (TSX:COS) is expecting 2015 crude output to come in at the low end of its targeted range of between 96 million and 107 million barrels as a result of the fire, which caused no injuries.
Canadian Oil Sands is the biggest partner in the Syncrude mine north of Fort McMurray, Alta., with a 37 per cent stake; other owners include Imperial Oil Ltd. (TSX:IMO), Suncor Energy Inc. (TSX:SU), CNOOC Ltd., Sinopec, Murphy Oil and Mocal Energy.