Canadian Natural completed an orderly shut-down of its Horizon Oil Sands Plant to complete unplanned maintenance on the Fractionating Unit in the Primary Upgrading Facility.

Since that date Synthetic Crude Oil production from Horizon has been fully suspended. The Fractionator separates the cracked hydrocarbons from the Coker into various components. It was initially Canadian Natural's view that this unplanned maintenance could be completed in a short time so as to return to full production levels by mid to late February, thereby not affecting the Company's ability to meet its 2012 annual production guidance for Horizon.

On February 11, upon gaining full access to the Fractionator, Canadian Natural determined the damage to be somewhat more extensive than originally thought, with a current estimated time to return to full production levels now targeted for mid to late March. As a result of this unscheduled downtime, Canadian Natural now targets 2012 annual production guidance for Horizon of 93,000 - 103,000 barrels per day of SCO down from its initial 2012 annual production guidance for Horizon at 105,000 -115,000 barrels per day of SCO.

Fourth quarter 2011 Horizon production averaged approximately 103,000 barrels per day of SCO.

Tags: Canadian Natural Resources Ltd