By Scott Haggett and Nia Williams
CALGARY, Alberta (Reuters) - Some of Canada's largest oil sands producers began scaling back production on Thursday after their natural gas supplies were cut back due to a pipeline rupture on TransCanada Corp's
Suncor Energy Inc
The 350,000 bpd Syncrude Canada Ltd oil sands project also has suspended shipments while Canadian Natural Resources Ltd
TransCanada on Thursday said the 1.6 billion cubic foot per day North Central Corridor pipeline ruptured in a remote area about 140 kilometers (87 miles) west of Fort McMurray, Alberta.
The rupture cut critical supplies of gas to oil sands operators, who need the fuel to produce bitumen and for the upgraders that convert it into refinery-ready synthetic crude.
Canadian cash crude prices strengthened after TransCanada issued its warning. Western Canada Select heavy blend for November delivery was last trading at $26.50 per barrel below the West Texas Intermediate benchmark, according to Shorcan Energy brokers.
That compares with a settlement price of $30.00 per barrel, below the benchmark on Wednesday.
Light synthetic crude from the oil sands for November delivery strengthened to $9.50 per barrel below WTI, compared with Wednesday's settlement price of $10.60 under the benchmark.
The line break has not affected all operators in the region. Royal Dutch Shell Plc
The North Central Corridor line, built in 2010, is part of TransCanada's Nova regional natural gas pipeline system.
(Reporting by Scott Haggett; Editing by John Wallace, Bernard Orr and Theodore d'Afflisio)