By Nia Williams and Mike De Souza
CALGARY, Alberta (Reuters) - Nexen Energy apologized on Friday for an oil sands pipeline leak in the Canadian province of Alberta that is one of North America's largest-ever oil-related spills on land, and said its clean-up crews were working around the clock.
The subsidiary of China's CNOOC Ltd said it is still trying to find the root cause of the leak in the pipeline, which was new and installed last year. It found a visible breach about the size of a hand.
The incident is another blow for the environmental record of the oil sands industry, already under fire from environmental groups for its carbon-intensive production process.
Ron Bailey, a senior vice president of Nexen who leads the company's Canadian operations, said the company is "deeply concerned" about the spill, which it detected at its Long Lake facility on Wednesday. The pipeline leaked 31,500 barrels of emulsion, a mixture of bitumen, water and sand.
The company said it thinks restarting the pipeline, which connects its Kinosis oil sands project to the Long Lake facility, will take "some time"
The spill covered 16,000 square meters and the Alberta Energy Regulator (AER) said the leak did not contaminate any water bodies.
The regulator has sent investigators to Long Lake to try and determine the cause of the pipeline failure.
Environment Canada's Enforcement Branch said it had opened a file on the incident, and was in the early stages of gathering information.
Nexen shut down the pipeline at its 72,000 barrel per day Long Lake facility, about 36 kilometers (22 miles) south east of the oil sands hub of Fort McMurray, and isolated it as part of the clean up operation.
Alberta Premier Rachel Notley, who on Friday finalised a Canadian energy strategy with other provincial leaders after a series of meetings this week, is also due to hold a press conference later on Friday.
(Editing by Jeffrey Hodgson and Christian Plumb)
