* April WCS last at $19.75/bbl below WTI
* April synthetic last at $6.00/bbl above WTI
CALGARY, Alberta, March 14 (Reuters) - Canadian oil prices were little changed on Thursday, remaining near recent highs on robust demand and supply concerns.
Western Canada Select heavy grade for April delivery last traded for $19.75 per barrel below West Texas Intermediate, according to Shorcan Energy Brokers, unchanged from Wednesday's settlement price.
Still, Canadian heavy oil prices have steadily improved from discounts that reached below $40 per barrel in January, when squeezed pipeline space and refinery maintenance work backed up the crude within the Alberta market.
Those pipeline issues have mostly been resolved and Canadian crude exports to the United States last week reached 2.7 million barrels per day, according to the U.S. Energy Information Administration, more than 700,000 bpd above year-prior rates.
Prices have also been supported by a light refinery maintenance schedule and few unplanned refinery shutdowns in the U.S. Midwest, the primary market for Canadian crude exports. Research firm IIR Energy reported on Wednesday that 1.48 million barrels per day of U.S. refining capacity is expected to be offline this week, down from 1.77 million barrels per day in the week ended March 15.
Light synthetic crude for April delivery last traded at a premium of $6 per barrel to WTI, also unchanged from the settlement price on Wednesday. Synthetic has been trading well above the benchmark on expectations that supply will be constrained by planned work on a hydrogen plant serving Suncor Energy Inc's 100,000 barrel per day Upgrader 1 unit and an expected full shutdown of the unit expected in the second quarter of the year.