(Adds details, background)
* Seen returning to full output in mid- to late March
* Damage worse than initially thought
* Production forecast cut to 93,000-105,000 bpd
CALGARY, Alberta, Feb 13 (Reuters) - Canadian Natural Resources Ltd’s Horizon oil sands plant will not return to full output until mid- to late March, as repairs to a processing unit at the northern Alberta site will take longer than first expected, the company said on Monday.
Canadian Natural, the country’s largest independent oil explorer, shut the plant down last week for what it initially believed would be minor repairs to a fractionation unit, which separates hydrocarbons from the coker facility into various components.
“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,” it said in a statement.
The company said the extended outage has forced it to cut its production target. It now expects the operation to pump 93,000-103,000 barrels a day in 2012, down from the previous forecast of 105,000-115,000 bpd.
The unplanned maintenance at Horizon, which has a capacity of 110,000 bpd, comes after discounts for Canadian synthetic crude widened to record levels into the mid-$20s a barrel under benchmark West Texas Intermediate crude.
The grade sold for about $18.50 a barrel under WTI on Monday, market sources said.
For most of last year, light synthetic crude sold for a premium to WTI due to a seven-month outage at Horizon that followed a devastating fire.
Shares in Canadian Natural rose 42 Canadian cents, or 1 percent, to C$38.17 on the Toronto Stock Exchange. The company announced the extended shutdown after the market closed. ($1=$1.00 Canadian) (Reporting by Jeffrey Jones; editing by Rob Wilson and David Gregorio)