04/24/2014 07:31 EDT | Updated 06/24/2014 05:59 EDT

Canadian Oil Sands revises Syncrude estimate after 'unplanned maintenance'

CALGARY - Canadian Oil Sands Ltd. (TSX:COS) is revising downward its production guidance for the Syncrude Canada oilsands mine north of Fort McMurray as a result of a breakdown at coker 8-1.

The company said Thursday that the "unplanned maintenance" work on the coker — part of the process to convert tarry oilsands bitumen into a lighter type of crude that refineries can handle — will overlap the turnaround of coker 8-2 scheduled for the second quarter.

As a result, COS has revised its estimate for Syncrude production in 2014 to a range of between 95 million and 105 million barrels — down from a previous estimate of 95 million to 110 million barrels.

The expected output equates to 35 million to 38.6 million barrels net to COS, the largest owner of the Syncrude mine with a 36.74 per cent interest.

The other owners of Syncrude include Imperial Oil Ltd. (TSX:IMO), Suncor Energy Inc. (TSX:SU), Chinese firms Sinopec and CNOOC, Mocal Energy and Murphy Oil.